66 mpg 2009 Totoya Prius, Champrius 4.0 Under Construction now
 

Howdy all!

I'm the creator and owner of Champrius, the Champion Camping Prius. (pronounced with stress like champion, not like Prius). My last revision of her (3.0) peaked at 66 mpg @ 65 mph unladen and got 61 mpg in real world use.

In March 2022 I had a fender bender that destroyed the boat tail and decided to do a major upgrade. I thought that the ecomodders here might like to follow the engineering odyssey. It will all be posted on Instagram; here is a good place to start:
https://www.instagram.com/p/CeeL6xyFp-k/
However, if you have in depth questions about the build I can answer them here. (I often exceed the Instagram message post length. ;-)

My goal this time around is to top 70 mpg in real world use, which is basically setting the cruise control to 65 mph on the highway and going +5 over the speed limit everywhere else. For those curious, my figures have virtually no hypermiling. The most I do is long slow stops for safety, which as a side effect helps regenerative braking and occasionally helps me avoid stopping. When I was doing active hypermiling, I was able to squeeze a good +10-25% improvement, depending on conditions. But that not only required a lot of attentiveness, it's not how most people actually drive. I'm interested in "fire and forget" improvements that could reach the mainstream.

Champrius has been around for years featured several places, including this forum. This thread has some good images (some of it obsolete stuff I've removed):
https://ecomodder.com/forum/showthre...tml#post616905
while this one has tries to reverse engineer some values:
https://ecomodder.com/forum/showthre...tml#post635155

It's also been featured on Jalopnik:
https://jalopnik.com/check-out-the-a...1832590335/amp
and all over Reddit, including r/WTF and my personal favorite r/Shi ttyCarMods. There have also been some viral TokTiks, etc. (Actually, I laugh my butt off when someone in the comments on Reddit says to sort the group by most popular posts... and 3 of the top 5 end up being about Champrius.)

Last but not least, I've discovered a new ecomod that I'd like to share, which was another reason for finally joining the forum. Here it is:
https://ecomodder.com/forum/showthre...tml#post669246

Enjoy! :thumbup:

I've hit a milestone! The new 4.0 version of Champrius under construction just topped 50 mpg!
https://www.instagram.com/p/Ce30CVQLQWk/

There's still a lot to do. I already know the tail will give me several mpg, and I have high hopes for the new nose cone.

For those interested, here's the current list of mods that got me from 39.2 mpg to 51.3 mpg:

DELETE: +% mpg gain [cost, time]
1.5% Rear and Passenger seats [$10, 2 hrs]
1.0% ~1/3 of the interior [$10, 4 hrs]
1.0% Antenna [$0, 2 hr]
1.0% Rear Windshield Wipers [$10, 2 hrs]
0.5% Rear spoiler [$0, 2 hrs]

REPLACE:
4.0% Tiny side mirrors, added vortex generators [$40, 4 hrs]
3.0% Smooth moon hubcaps from pizza pans (rear only atm) [$100, 6 hrs]
2.0% Max tire pressure 44 psi of low resistance tires [$0, 10 min]
0.5%+ Hood insulation (better colder / short trips) [$50, 2 hrs]
0.5% Gas Cap, Radiator Cap [$30/100k, 20 mins]
0.5% Air Filter[$20/30k, 15 mins]
0.5% Synthetic oil [$80/10k, 2 hrs] with oil catch can [$40, 4 hrs]

ADD:
5.0% Extreme grille block to 40 sq in [$20, 15 mins]
4.5% Solar Panel as partial Kammback [$500, 6 hrs]
3.0% Dual Cat Shields [$300, 8 hrs]
3.0% Windshield wiper deflectors [$40, 2 hrs]
2.5% Wheel fairings (partial skirts for easy maintenance) [$50, 4 hrs]
0.0% Shrouded ceiling vent + signal booster [$200, 4 hrs]

Can you go into detail about the VGs with the smaller side mirrors? I replaced my super silent factory side mirror with a hand crafted mini side mirror, but the wind noise is insane from it and really annoying at higher speeds.

Hey Phase! Sure.

First of all, I bought the mini side mirrors. They came with already curved backs, and were 5 sq inches in area, which was exactly what I was looking for. So I don't know what can be done about your hand crafted mirrors except to shroud them with a smooth manufactured shaped.

As for the vortex generators, VGs are used to re-attach flow separation to a surface, like behind a mirror or to a back windshield / trunk that's concave to the airflow. They "inject" higher pressure air into a low pressure "shadowed" zone. Both airflows are turbulent, but when properly used the VG causes earlier re-attachment and thus better flow.

Each VG comes with a characteristic length L and width W. They are usually designed so the two are comparable. You want the turbulent unattached zone to be between 1L - 3L behind the VG, and if large enough, to place multiple VGs around 1W-2W apart. (Placing them closer than 1W at best does nothing and at worst interferes with each other.) Also note that we want at least 2L flat surfaces ahead of the VG for effectiveness, but often we can't get that near a mirror. (It's much easier on a roof, say.)

To give you real numbers, the gaspods I'm using have L = W = 3 inches. So I want to place them 3"-9" ahead of the separation point from the mirror, and around 3"-6" apart.

To find the separation point one can use tuft testing / smoke injection / look at the mirrors in a rainstorm / anything else that visualizes airflow around the mirrors. If you know the W and L of your VGs, place the tufts around 2L apart horizontally and 1.5W apart vertically. See where the flow becomes separated and put the VGs ahead of it.

You can see videos of me tuft testing here:
https://www.instagram.com/p/Ce13TiGFm0_/
and I'll take a pic of my current setup and post it in a moment.

Note that mirrors are notoriously finicky and you shouldn't use my setup as a template. I've seen other cars where the optimal placement was below the mirrors, they needed 3 VGs to cover the whole separation, they were placed differently, etc. Also note this isn't the optimal placement even for my car; it should be an inch ahead and both two inches lower. But there wasn't nothing to stick them to, so I had to compromise putting them on the mirror plate.

Be aware that VGs can also make a whistling noise. I originally used the gaspods on the front edge of my spoiler, where it met the rear window. It gave me a whopping +7-11% FE, depending. For an already optimized car, that's astounding. I took them off a week later, because they caused a heinous low level shriek. I'm an audiophile, and the improved mileage wasn't worth going batty from the noise.

Last but not least, if you are custom crafting your mirror, then I've seen other VG variants that might be more suitable for you. One had very tiny L = W ~ 1 inch VGs along the outside rim of the mirror. It directly injected air into the shadow (instead of onto the side of the car like I'm doing). Another is a flat flap used like a winglet on an airplane wing. That has the dual use of being a vortex stopper and a VG. Anyhoo, those might be appealing options.

Hope this helps!

A picture is worth a thousand words. Enjoy!

Looks too big.

Haven't you tried to copy Toyota's OEM vgts?
Like this: https://m.media-amazon.com/images/I/...AC_SL1500_.jpg

That's actually what the handmade ones I had before looked like. But from what I could tell on the tuft and mpg tests, it didn't seem to matter.

Also, I placed one higher up because it straightened out the lines that flowed over the roof, which were pretty chaotic before.

Hmmm... I wonder if it might even be better to *remove* the one near the mirror instead. Something to experiment with someday.

For what I understand, they are mounted backwards: the blunt should be facing rearward. So what is your logic process to install them?

They are mounted correctly. Different VGs have different orientations. You might be thinking about triangular VGs, which are often placed fat side to the back of airflow. These are aerofoil VGs called Gaspods:
https://aerohance.com/

As for the logic process... I detailed that just a few posts ago:
https://ecomodder.com/forum/showthre...tml#post669668
Let me know if you have more specific questions.

Well, we might be seeing the beginning of the end for Champrius:
https://www.instagram.com/p/CfHZAqXFjB3/
Something in her radiator just failed and it doesn't seem safe to drive her currently.

I'll keep peeps posted, but it's going to be a week before I can even get into a shop to see what's wrong.

Yikes! What's the symptom.

So prius prime and then mod it? Champrius prime?

The sad sad facts
 

The main error codes seem to be:
P1121 - https://lusciousgarage.com/blog/priu..._sensor_stuck/
P0A93 - https://lusciousgarage.com/blog/priu...r_pump_seized/
I'm also getting the Red Triangle of Doom and a red warning on the MFD, which I've never seen before. That can't be a good sign.

My guess is that the inverter coolant system is horked somehow. After doing some reading it looks like the coolant control valve getting stuck is a common problem, and in an old car just needs to be replaced. That's a $500 repair.

If I get lucky, that's why the inverter pump isn't working. If I don't that also needs to be replaced. That's at least a $500 repair.

If I get super uber lucky, the AC is still working and the reason I'm getting no cold is the coolant valve is dumping heat into the cabin at the same time. If the AC is out... that could be anywhere from a $200 to $2k repair, depending.

I've already called my Toyota dealer and have the car scheduled for an appointment for next week. That's when I'll find out how bad things are. If we are looking at multiple thousands of dollars to get Champrius ship-shape again... I have to seriously consider mothballing her and getting a new car. And right as I was knee deep in the mods for her, too. (sigh) :(

Hahaha! That made me think of Optimus Prime. :)
https://static.wikia.nocookie.net/ro...20140919185127

Actually, I think if I get a new vehicle it will be electric. Probably a Tesla Model Y or an electric van if I could score one. As much as I love the Prii, I think I want to migrate off of fossil fuels entirely and jump on the e-bandwagon. :thumbup:

My goal is an Arcimoto FUV. What do you think of the xBus?

DDG:

The Arcimoto does indeed look like fun. The xBus is also a cute vehicle, but doesn't fit my use case. It doesn't have good aero, and doesn't look like it would be good to live out of for weeks at a time.

I was excited by Canoo and Rivian awhile back
https://www.canoo.com/
https://rivian.com/
But unfortunately, both of them got distracted from their original goals. Canoo wanted to build modular custom vehicles, and is now doing stuff for NASA. Rivian wanted to build outdoor adventure trucks, and is now building vans for Amazon.

And those are just two of the actual, real, non-vaporware companies. There were a ton of places that rode the electric hype, scored funding, and then disappeared. It looks like for the moment that Tesla is the only real alternative for an electric car. I wanted to use Champrius for another few years until the other car companies seriously got into the electric game, which would hopefully increase options and decrease prices. But it's looking like that may not happen, first, because supply constraints are driving up all electric car prices, and second, because (gulp) Champrius may not make it that long.

I like the Canoo, too. The transparent A- and C-pillars.

From the article I linked it looks like xBus has supply chain problems.

Expensive but OEM:
Edit:
https://media.hagerty.com/media/wp-c...20190905183357

My 2006 Prius just had the inverter coolant pump fail recently at 265k miles. Same code you have P0A93, but I didn't have any other codes with it. I was able to validate the pump wasn't running, and I swapped it with one from another Prius I happen to have ($500 beater/parts car, cats were stolen). Anyway, swapping the pump was a bit of a pain mainly because of the tight working area, but besides that it was pretty easy to do with just basic hand tools. It looks like the valve is in a similar location. A new OEM pump is around $110, aftermarket (probably Chinese) is $25 if I remember right. I've always been a DIYer though and it helps my dad was a mechanic, so I grew up around fixing cars and such.

Good luck with the repairs, sounds like pretty simple issues to get solved, but might be expensive to pay someone else to do them.

Hah! Champrius just broke 280k. Maybe the inverter system failing around now was planned obsolescence. :)

Hmmm... you raise an exceptionally good point, though. My options aren't limited to a) pay lots of money for repairs or b) get a new car. I could take option c) attempt repairs myself on a car I was going to junk otherwise anyway. That's definitely a lower cost option, and if I get lucky and don't screw anything up, potentially just as good.

I'm still going to take the car in and get it diagnosed professionally, as I need to know whether the problem is with the valve and/or the pump. But after that depending on the situation, I might (ahem) take matters into my own hands.

Thanks ps2fixer! If I royally hork my car, it will be because of the bright ideas you placed in my head. :thumbup:

If it doesn't work out, bring the car to Michigan and I'll pay ya scrap value for it =).

Not much to mess up on the pump, it's 2 hoses and a 2 pin electrical connector and 3 mounting bolts. It's just a tight fit getting to it. After it's hooked up, you turn the car on and open the bleeder to purge the air out. There's some youtube videos on how to do it.

It's pretty easy to check if the pump is running, just turning the car to ready mode the pump will be running. If you feel no vibration on the hose, or can't see any flow in the resivor, then the pump isn't working.

The engine coolant valve code sounds like one of the issues existed, and the other recently popped up since the engine coolant system and inverter coolant system are isolated. The only thing they share is the radiator, but the compartments are separate.

If your car has the factory catalytic converts on it yet, those are worth close to the value of the car, worst comes to worst, could cut those off and get someone to pay a fair price for them (or ebay them) and sell the rest of the car to a junk yard or scrap yard. Locally that's $200/ton and the car is 1.5 tons. That puts scrap value around $1500-1800 complete.

Always good to look at all options, I'm huge anti debt for the way I live, so the only way I'd replace a vehicle is if I could afford to buy it out right with no loans. Save a ton of insurance, no interest, older car plates are cheaper. Generally older cars also have cheaper insurance as they are safer too. My 1997 Corolla was cheaper insurance with 2 air bags than my 2006 Prius. Insurance company owner told me it's because there's more metal in the corolla and there's less chance of getting hurt in a wreck. That reminds me, I recently got a dash cam I need to install, and I need to ask my insurance company if there's any kind of discount for having the dash cam. It makes legal battles much simpler if there's ever an issue, no going off of what someone says, just watch the video.

My Corolla hit 305k miles before the gas tank straps rotted off the car, still runs and drives but from sitting the brake lines rusted out too. I also have a 92 camry with 300k miles. My dad's Toyota T100 pickup 4x4 has 330k miles and still going. Toyota makes very good vehicles, just Michigan is terrible on any vehicle due to the salts used during winter. My 1990 Lexus LS400 is just getting a little rust around the wheel wells in the rear (it's RWD) and V8 powered, but it only has around 240k miles currently.

Anyway, I replaced my pump and all seems good with my car, code didn't come back and I put the grill block back in. When the code came up, I removed the grill block and it didn't come back, so efficient driving can keep the inverter from over heating even with no coolant flow.

There's always a plan D too, if you have any colleges near you, call them and check if they have an automotive repair class. It's pretty common for them to work on vehicles for people so the students get hands on experience. I'm not sure if you have to pay for anything besides parts or not though. If you know anyone wanting to be a mechanic, it's a simple enough job to do, not much to mess up besides not "burping" the system or leaving a hose clamp off. I'm sure my cousin would have loved to be paid to fix a car back when he was taking automotive repair classes. I think he was in high-school back then too so that might be another spot to check.

Either case, good luck with whichever route you go with the car.

Talking about the car, I was hoping I could get 50mpg out of my car driving it "normal", but I got 46mpg instead. Once I slowed down and tried to coast as much as possible (nothing too extreme) my last tank was 55mpg. I see trips 60-65mpg fairly often, but I'm traveling at 40-45mph in a 55mph zone out in the country and 55-60mph on the express way gets me about 50mpg for longer trips with just a lower grill block. My cat is reporting as bad (P0420), but I live in a state with no emissions testing, so probably going to delete it and cash in on the scrap value of it and get to keep the car still. I've wondered if the cat being deleted would effect mpg much as it is a bit of a restriction in the exhaust. Not exactly the best "green" mod to do of course, but buying an electric vehicle isn't really green either when you consider where the power comes from (most likely coal for most areas of the usa), how the car is built, batteries, mining for materials, etc.

I'm actually very similar in philosophy. I decided a long time ago to never buy a new car and always get used ones. The price to performance ratio is just so much better, if one is willing to accept occasional service outages. The second big decision was to never own a home or property. Not having a mortgage allowed me to travel the world and have many great experiences. The third big decision was to retire early. I'm far happier living modestly on a fixed income than I ever was on my hamster wheel running the rat race. :D

Yea I'm similar, but I like to own my stuff. I hate debt though, my house was the only real loan I've had and I worked with the owner so 0% interest for the first 5 years, paid it off in 4 years and the last year I went self employed and income was way lower.

Since I'm self employed full time (since 2013), it feels about like I'm retired, but I still "work" on things. I enjoy most parts about my work though. I used to work a "normal" job before, first one was a bit boring but it was midnights. Other job was in the health industry and that company was ran terribly, everyone was over worked and overly stressed out. After I quit the business was sold like 3 months later and my whole department was fired.

Anyway, I hope to retire early, only mid 30's right now, but I have some money saved up and investments and such. If all goes well my retirement should be paid for at 65+ if the investments perform as expected and inflation doesn't eat it all up, but I have to pay my way from now to 65 with what I have currently. Hopefully my business scales up well and eventually have people work for me and I can focus on more of the fun aspects of the business which is also the niche thing most people don't want to invest time into.

I've done enough traveling picking up junker/scrap cars, vacations are fine, but I never really got too big into just traveling to travel, too many other things weigh on my mind that I could be doing instead of traveling I guess.

Sounds like you need lots of header wrap or maybe the catalyst just needs to go bye bye.
Too much belly pan has caused cooked wires, fried sensors, gas tank boiling for other people.

Hehe. I was actually one of those "other people" on my first version. I naively covered everything up on my first go around and started cooking the interior cabin. I got super lucky that I did it in the Fall and found out about it in Winter. I think that if I had done it in Spring... it would have been adios Champrius. :D

This time around I left the original airflow mostly intact:
https://www.instagram.com/p/CfHZAqXFjB3/
So air has a continuous path from the engine bay to exit in front of the gas tank, just like the Toyota engineers intended. The only thing I changed was the flow to the wheels. They had channels that 10% of the air would use to deflect in front of each of the rear wheels. But that snakes around a lot of the underbody as well. So I decided to seal all the off and dump all the air in the center.

Something else I'm proud of is that I left the pipe exposed. When you look at the stock underside, the pipe is clearly below the belly pans (see attached pic.) In earlier designs I covered that up, and it slowly cooked the plastic. In v4.0, I've decided the engineers probably wanted it exposed to airflow to cool it or somesuch, so I've left it alone and continued the belly pan underneath it.

You could use metal screen over the exhaust, I think that's how areo civic was done, but it's a long time since I looked through the thread.

Build thread:

https://ecomodder.com/forum/showthre...1-0-a-290.html

Right now the cats are covered by two cat shields made out of aluminum. Those seem perfect, since they are actually designed to withstand the heat. If I were to ever cover the muffler, it would be with something similar, i.e. a thick sheet of aluminum. But at this point I'm not certain I would even gain that much from it.

I used to use chicken wire over air inlets, but this new design doesn't have any on the underside. And I've learned the benefit of leaving outlets open to clear water and debris.

Howdy all!

Champrius has reached another milestone; she just topped 55 mpg on my standard benchmark run.
https://www.instagram.com/p/CfrnG34FE0n/

Moreover, things have gotten spicy. I have a gentleman's wager how much modifying the front of a car will gain in gas mileage. I believe I can get 8+ more mpg, whereas aerohead has called me out and said flatly there's no way I'll even gain 4. You can see the evolution of the bet here if you are interested:
https://ecomodder.com/forum/showthre...tml#post670114

So if I can get 65+ mpg consistently I'll win the wager, whereas if I'm stuck below 60 mpg then I'll bow to aerohead's oracular wisdom. In the middle it might be too close to call because of testing error.

It's raining all this week where I am, so I'll be focusing exclusively on the front starting next week. The race is on! :)

Here's the current list of mods for the car that bring it from 39.2 mpg to 55.6:

DELETE: +% mpg gain [cost, time]
1.5% Rear and Passenger seats [$10, 2 hrs]
1.0% ~1/3 of the interior, spare wheel, jack, etc. [$10, 4 hrs]
1.0% Antenna [$0, 1 hr]
1.0% Rear Windshield Wipers [$10, 2 hrs]
0.5% Rear spoiler [$0, 2 hrs]

REPLACE:
4.0% Tiny side mirrors, added vortex generators [$40, 4 hrs]
3.5% Smooth moon hubcaps from pizza pans [$100, 6 hrs]
2.0% Low rolling resistance tires [$400/80k, 2 hrs]
0.0% Max tire pressure 44 psi [$0, 10 min] (safer to say we lose FE for underinflated)
0.5%+ Hood insulation (better colder / short trips) [$50, 2 hrs]
0.5% Gas Cap, Radiator Cap [$30/100k, 20 mins]
0.5% Air Filter [$20/30k, 15 mins]
0.5% Synthetic oil [$80/10k, 2 hrs] with oil catch can [$40, 4 hrs]
0.?% LED lighting (inside, headlights, etc.) [$70, 2 hrs]

ADD:
15.0% Full 42" boat tail with tail box [$450+, 18 hrs]
3.0% Windshield wiper deflectors [$40, 2 hrs]
3.0% Dual Cat Shields [$300, 8 hrs]
2.5% Wheel fairings (partial skirts for easy maintenance) [$50, 4 hrs]
2.5% Mid pan [$50, 8 hrs] + Rear Diffuser [$75, 6 hrs]
0.0% Shrouded ceiling vent + signal booster [$200, 4 hrs]
0.0% Solar Panel as partial Kammback (superceded by tail) [$500, 6 hrs]

Figured it's worth a mention, us ecomodders that don't have an insta account can't see your posts/updates as it requires a login.

I think 4mpg is doable, 8mpg might be pushing it for the front end mods unless you're counting stock front vs adding grill block and such. With a grill block I'm sure there's improvements, but I don't think there's much to gain on the prius in that area. Air dam all the way down to the road, wheel splats, wiper deflectors. If you go extreme, you could try to reconstruct the shape of the nose, but I don't think it's too bad of a shape stock.

Either case, will be interesting to see how things turn out (or read since I haven't even seen a pic of the car yet lol)

That's odd. My account is public and my posts are global. Anyone should be able to view them.

I just went to my account from a fresh browser and was able to view everything just fine. Try my main Instagram account and see if that works:
https://www.instagram.com/kimlumbard/

I'm redoing the whole front end, including: a new air ducted inlet for the radiator, shaping as much of the outlet as I can, a much curvier and pointier nose, air curtains, and my secret special sauce. :D No worries if you are in the doubting camp with aerohead... prepare to be amazed in a few weeks. :eek:

I've attached a pic from the tail end, which was the last major mod I completed. Once I get the front done, I'll take some posterity pics and post them on Instagram and here.

Here's what I see at that link. Try a private browsing window, that will clear login cookies and such.

https://i.gyazo.com/b4e1b8bc2f1c7fe1...33e361e35a.png

I'm not completely in the doubter camp, I do think there's gains to be had, but ~8-10% or so is quite a lot. I remember there was a challenge a while back where a team drove a prius for a whole tank and hit a crazy tank average like 100mpg. I don't recall if it was a stock car or not, it was driven at more ideal speeds (25-30mph average I think), no radio, windows up, hot day, etc.

Didn't realize you had a full boat tail and such. You could easily hit those goals with slower speeds =). I'm running a nearly stock prius 45mph and for any kind of longer trip I'm hitting 55mpg or so, just have a grill block and missing a couple bell pan panels lol.

It looks like you live more in the city, I suspect it's more shorter trips for the car and such. You could probably see some big gains from a block heater, trans heater, etc. My MPG is horrible when the car is cold. It starts off around 30-35mpg and climbs at 40mph. There's also a mod to spoof the temp sensor to help get it to turn the engine off a bit sooner and such, I haven't messed with it but read about it. It currently takes my car around 6-7 miles to come up to temp.

Know your opponent
California98Civic -- Bonneville 2012
ecomodder.com/forum/showthread.php/phil-knox-fleet-34-years-aeromodding-1280.html#post628587

We have a mystery! I used a Private Window on Firefox, and I've attached what I see. There is a login bar overlay at the bottom, but it doesn't prevent any of the posts from being clicked, read, navigated, etc. How about if you try a new fresh browser?

Anyhoo, one of the reasons why I dual post to Instagram and Facebook is because FB definitely doesn't let people see things without having an account. But (in the past at least) Instagram does.

Actually, I'm claiming I can get +20% mpg from my baseline of 39 mpg = +8 mpg. So much more than +10%, which is what aerohead (and apparently you) thinks is the limit. :D

I'm uninterested in achieving high mpg for bragging rights. I use this car for extended camping trips, so I travel on the highway a lot. So what I really am trying to optimize is FE at 65mph cruise control.

I'm also not trying to win the bet just to win a bet. I honestly think there are real mpg gains to be had at the front of the vehicle. If that's the case, it's an area for substantial aero improvement that currently isn't being explored or exploited fully. If it's not the case, then I'm just deluded. :rolleyes:

Champrius and I are both snowbirds, so we rarely see cold. In my case, it's because I'm solar powered and love the sun. In her case, it's because her ECU shuts off when it rains or gets too chilly. :eek:

So is Phil Knox = aerohead and that's his vehicle?

The 4.0 front of Champrius will be *way* better than that vehicle. You know, assuming it works. :p

I'm curious how much the sloped fairing in front of the windshield cuts down on drag. One of the things I wanted to experiment with after modding the front of the car was something similar, to replace the windshield deflector. It would be nice to know if it's worth doing.

The other is the side mirrors. I saw another fellow on here with a good idea for them, to place them farther out. I've been using VGs to try to reduce the shadow, but I think we can do that in other (hopefully better) ways.

ecomodder.com/: Sticky: Index of Phil Knox Aerodynamics Seminars & Mod-data lists

Not secret, maybe not obvious.

The pic dates to 2012. The cowl deflector didn't make the cut.

Mirrors need to move away from the A-pillar; peep mirrors, fender top mirrors or stalks forward from the windshield header. [IMHO of course]

I did it in a private window, same thing. I'm on Linux but that shouldn't effect things. I jumped in my Windows 7 VM and it does the same thing as well as well as a server I have setup that runs windows 7. I've had other people link insta posts before but can never view them as a guest.

Kind of funny, for me facebook works as a guest, this is my facebook group, but it's a public group. Twitter also works as a guest, but you have to click posts the right way to view comments or it wants you to login (very annoying). Weird that you can load insta with out logging in though, I suspect you're on windows 10/11? I refuse to install that spyware that Microsoft made. I'm probably pretty biased since I'm fairly deep into computers and I know how info can be used.

https://www.facebook.com/groups/derbyws

Anyway, not sure what you mean exactly by fresh browser, like reinstalled type of fresh? Chrome isn't an option for me due to their terrible privacy issues, and there's no IE on Linux lol. Facebook is terrible too, but I only use it for business.

I see, I didn't have all of the details on what the claims were. I think the grill block is good for around 10% vs stock. My corolla with grill block and half belly pan under the engine and passenger mirror delete would get 38-44mpg, drive home unmodified the car got 33mpg with a bunch of issues I fixed right away.

Anyway, you're looking at a base mpg of 40mpg (mine is 46 with panels missing driving "normal" lol) and the target is 65mpg+ with all mods, not just the front end?

Of my understanding there are larger gains at the rear of the car vs the front. The high pressure zones at the front kind of work out to make an effective areo shape that most of the air flows over. The air dam and such up front helps, but it's it's to redirect the air to less turbulent areas of the car. It's been a long time since I read about the areo civic, but if I remember right, the custom shaped nose cone vs the mostly (or fully) blocked off stock nose was good for like 5% difference.

I do long trips somewhat often, 55-60mph on the express way, the energy to over come the wind drops quickly at those speeds. I just drove my prius to a couple cities away going 75mph (pressed for time) and with the highway driving and city I pulled 50mpg going to the place. On the trip home I went 55mph expressway and around 45mph on back roads and pulled 64mpg according to the scan gauge. Expressway speeds at 60mph with no slower sections I hit around 50mpg as well (based on a ~1.5hr trip with 4 people in the car and such). For my car anything over 45mph the mpg drops lock a rock. With a boat tail and such it should make quite a difference I would think.

I haven't personally experienced having a boat tail yet but I'd expect it to be by far the largest single mod you can do. There's a lot of other little mods that add up pretty fast though.

Here's a section about the areo civic. It's basically modded to the max, manual trans, lean burn Honda engine. Based on these numbers, that car should see roughly 80-85mpg on a long trip at 65mph (with today's' 10% ethanol gas). The prius doesn't seem to do well for high speeds vs low speeds, I suspect it's because of the CVT setup with the electric motors and battery requirement (more drive line losses than a manual trans at high speeds), it really shines at low speed and 40mph and under auto engine off coasting and such. Can your car hit 65mpg at 65mph, I think you'll get close. At such high speeds, it might be better to remove the solar pane or rework the boat tail so it's flush, the leading edge and tunnel effect I think creates a lot of drag, even dropping it down flat and reworking the front and rear edges I think could see some reasonable gains.



Anyway I played around with some numbers, with the areo civic level of CD, you should be seeing around 65-70mpg at 65mph. If you change it to 60mph and it looks like 75-80mpg is possible.

My guess is your car is sitting around .21 (factory is .24) and you're targeting around .18. Of course all of those figures are guesses based on some areo calcs and such, I'm far from any kind of expert. I think if you did the full blown Areo Civic setup, you could hit the goal.

https://www.aerocivic.com/imgs/front-3-4-z.jpg
https://www.aerocivic.com

Hmm. I wouldn't think the OS would be a factor, but perhaps it could be. I am on Windows 10. By the way, if you are interested, I wrote a script to turn off the telemetry and unnecessary services. Every time Windows did an update, it would reactivate it's crap, so I made something that automatically turned it all off again. Anyhoo, if you use a debloater and my script, it actually changes Windows 10 into something more reasonable.

Yes, fresh install kind of fresh. If you are on Linux, Safari or Opera are good choices.

Wow. The best I ever got from my grille block was 5%, and that was with something that I felt was unsafe to actually use. The grille block I settled on was around +3.5% mpg.

For the wager, yes. My actual goal is 70 mpg unladen with Champrius 4.0. I'm hoping to get high 60s by redoing the front, and then to refresh some other mods I already have to push me over the 70 mark. That would mean that once I dump in all my camping gear I should get mid 60s at 65 mph.

That's everybody's understanding... because they haven't seriously considered modding the front as a whole unit. I'm not going to be doing what basjoos and everyone else has done. I'm trying something brand spanking new which I believe will be much better.

On v3.0, the boat tail got me +20% mpg. On this last version, it netted me +15%. It's pretty substantial.

Crazily enough, on the previous boat tail, the solar panel had negligible impact. If it reduced mpg I couldn't tell. I think it was because it was so well oriented with the airflow. On this version, I don't know. The v3.0 was flat and straight from above. The v4.0 version is more rounded and tapers in all directions. So the back edges of the panel are probably interfering with airflow.

Before all my car troubles, v3.0 got 66 mpg at 65 mph unladen. That's why I'm pretty optimistic I can achieve my claimed numbers; I've already done it before. :D

The Gen II Toyota Prius has a 0.26 drag coefficient stock, not 0.24. My previous version was around 0.21, and my goal is 0.185 Cd (good guesses!).

We'll see how things stack up against the Aerocivic once I'm done. Onward! ;)

I see, lot of effort to see posts on a site that I very rarely visit (like 2 times in my life I've wanted to view a page there lol).

I'm sure windows 10 can be changed so it's not so bad, but I don't support the company and how they view privacy and such, so I don't give them any of my money. I build my own computers and have been wanting to run linux for a long time. My windows 7 I paid for (win 7 ultimate), I really should have just went with pro since it's way more popular and seems to have less problems but overall it did ok. I miss the days of xp when things didn't have animations and such as much, everything felt so instant and quick unless there was some real processing needed lol.

On my corolla, it was a massive effect. I didn't drive my prius much with out a grill block to really get a feel what the effect is like, I just knew it was a real easy low hanging fruit. Once I have a solid way to monitor inverter temps, I plan to do a full grill block, right now it's only the bottom blocked off which isn't ideal since the inverter section is at the bottom. It's more than enough for the engine though, With the corolla I left around a 6in wide opening on the bottom for winter time and completely blocked the upper grill, sealed around headlights and hood (tiny help but isn't massive, it helped retain heat much longer though).

I recall someone reshaping the front of their car, I keep thinking it was the areo civic where they had clear plastic from the front bumper arched up to the roof line. There was increases, but it added a lot of problems and the idea was scrapped. One is cleaning the outside, windshield wipers work on glass pretty well, but it doesn't play so nice on plastic and such. The other issue is the inside of the plastic gets dust and such on it and is hard to clean. If you reshape the whole front end, I know there's gains, but that's not exactly as easy to do, I think even a boat tail is easier which I suspect why most people focus at the rear side than the front.

If you was driving a van or truck, I could see larger gains reshaping the front end. I think the Prius shape is reasonable. It can be improved on for sure though. I suspect if you rework the front end to be more of the ideal shape, it's going to mess up the areo in the back, about the best solution I can think of is make the nose the ideal shape, then have a straight section back to the roof line. The clear material used will likely make things appear a bit funky though. Not sure how the laws are around a mod like this. Starting with a van might actually be more ideal for the desired shape but small vans prius sized with hybrid systems I don't think exists, at least not common in the usa lol.

The first google result said .24 for stock prius, but can't ever trust a single source lol. When I was playing with the mpg areo calc I actually bumped the cd to .26 and increased frontal area a little to get numbers that looked more correct to me for the experience I've had with my 2006 prius.

I'm not sure how accurate the coast down cd calculation is, but it would be really interesting to see those numbers along side things. It's smaller number changes, but going from 26% of drag vs a wall down to 21% is still a lot. I'd think the prius is more of an ideal shape for lower cd so if you do a full car overhaul similar to the areo civic but with the more ideal front end, you should be able to beat his cd numbers (in theory at least). Wheel skirts and mirrors I think are a couple areas that could be reworked pretty easily to see good sized gains too.

Have you looked into the mirror laws for your state? Here in Michigan driver side and rear view is required, and it defines it as being able to see objects behind the car like 1000 ft. Most laws don't account for modern tech (I see the backup camera), ideally no mirrors would really be needed if cameras and screens were used.

Too bad your prius wasn't a 2010 (maybe engine/trans swap some day?!), they can be in electric mode at a much higher speed than our cars. Clearly it's not ideal to run off electric, but it gives the option of shutting down the engine after the battery gets charged up and such. I think that's likely a large part in why they seem to run around 10mpg (20% or so) higher mpg averages.

I'm still kind of amazed at my old corolla, I could go 60mph on the highway and hit 40mpg on long trips. My prius in it's current form hits around 50mpg under the same conditions. The prius has stock belly pans and such, where the corolla I had to add them and I didn't fully cover the belly. The corolla is about 400lbs lighter and is a little less frontal area, so what the prius does is still pretty amazing, but it would be even more amazing if it was corolla sized.

Using the same figures, 40mpg to 65mpg for you, I should see roughly 50-55mpg turn into 81-89mpg. I don't think it's a 1:1 comparison for me, but it would be interesting to hit 100mpg+ with a prius at somewhat "normal" speeds. I'm not super worried about the look of this car. I got it for cheap. I just haven't had much time to do mods to it. First thing I want to do is fix up the under body panels or recreate them to get it back to somewhat stock. Hub caps, fender skirts, probably something todo with the passenger mirror (need to keep it encase I'm hauling a trailer so I can see better). I've been thinking a boat tail would be interesting, would like to design something that folds up and can be stored inside the car and likely attaches to the hitch so when I need to haul a trailer I can swap it out somewhat easily. I think my concept would look somewhat similar to how yours appears. I don't expect gas prices to get better for quite a few years so it's not going to hurt anything saving extra money on fuel (main reason of owning the car) =).

When you decide to run Linux, it should take about an hour. Populate a USB drive and boot from there.

Else, do what I did and throw down for a Raspberry Pi 4B and do an immediate and regular update/full upgrade in the Terminal.

I left the Apple ecosystem instead of Windows, at least for the world-facing machine.

It's been a while since I posted this:

https://ecomodder.com/forum/member-f...e-wheel-up.jpg
https://ecomodder.com/forum/member-f...wheel-down.jpg

Mocked up since I had the parts lying around. I'm more inclined to a receiver hitch box.

I've been on linux full time for about 6 months. I have some programming tools (IDE and such) I need to find alts for, but so far it's working well. There's a couple things with the file manager I don't like, but can uninstall it and install a different one, just haven't messed with it.

I've installed linux before in VM's and such, but never full time for my daily computer till the 6 months ago. Either case, a website shouldn't change based on what OS you're running unless it's for like pc vs cellphone type of logic which can be done in a lot better way.

Apple is the distant cousin of Linux/Unix, somewhat like how Android is related to Linux as well but google has their fingers in that one.

I saw those pics, or something real similar not long ago, not sure what I was looking up but I remember the fold up wheel. Guessing the concept is the boat tail folds up behind the car? The prius is a hatch back, so there's a reasonable amount of storage inside, just need to make it fold up small enough to fit inside, or pull pins, etc.

Would be funny to make an inflatable boat tail from something clear. Not sure if the cops would like that too much since the license plate might be harder to read, but if there's an on board air pump, it would be pretty quick to deploy or take down and ideally should take up almost no room. I'd guess it would have to be pressurized a fair bit though to be stable in the wind.

You can see how I misinterpreted the quote?

What flavor of what Richard Stallman would want us to call Gnu-Linux do you run? Raspian is somewhat limited. The Pi 4B doesn't even have a real time clock.

I was with Mac OS from 7.1 IIRC. But when they pivoted to OS X, my favorite tool Norton Disk Editor was never brought forward. Symantec paid me to sit in a $900 chair at their knowledgebase terminal and bring back peoples' data files from the Void. It was the most satisfying work I had.

Boat tails!

Other than the mockup on the Superbeetle, I also did a scale model you may have seen.

https://ecomodder.com/forum/member-f...pe-ii-boat.jpg

This is hinged like a single wheel trailer. The rigid floor would help the difusser and stiffen the structure, shown as fiberglass rods ribs like a mountaineering tent. It should have a wheelie bar for ground strikes.

This is from the 1960s. :)

https://ecomodder.com/forum/member-f...nd-inflate.jpg

edit:
Here's a front for the VW Type II:

https://ecomodder.com/forum/member-f...ocalmotive.jpg