RobertSmalls' Prius C
 

I've got a new vehicle: a 2012 Prius C. This replaces my ecomodded 2000 Insight as my daily driver.

http://farm9.staticflickr.com/8068/8...32c4c3f1_k.jpg

The fuel economy won't be as good as the Insight's, and I'll miss the way the Insight lets people know I'm serious about fuel economy. But all in all, I like the Prius C so far.

I plan to EcoMod the Prius C, but in more subtle ways than I did the Insight. Any externally visible modifications must look like it could have come from the factory that way (plausibly deniable). On the interior, I'll allow myself a freer hand, but I won't tear out half of the interior panels like I did on the Insight.

I've already removed the 541g owner's manual and the rear floor mats. The rear speakers are slated for deletion, but I'll make sure you won't be able to tell. If I can go the whole winter without wanting to turn on the rear wiper, then I'll delete it in the spring. I don't expect big gains from minor weight reduction, but every little bit helps.

I'm hoping to get bigger gains from instrumention, electronic modifications, a grille block, and possibly an engine block heater. I've pumped up the tires to sidewall max.

Here's a shot of the two cars, with the camera level with the Insight's roof:
http://farm9.staticflickr.com/8059/8...27f8677e_k.jpg

I do love the stick shift in the Insight, but I believe the Toyota transmission is more efficient in most cases. Toyota Prius - Power Split Device

The Prius C is no wider, 2" longer, and 3.6" taller than the Insight. A Prius Liftback (the "regular" Prius) is 2" wider, 21.1" longer, and 5.4" taller than the Insight.

I could go on for hours, and I probably will at a future date. But that's all for now. I'm looking forward to seeing what this car can do.

Robert,

First of all, welcome back to EcoModder!!

I have not seen a post from you in a long time!

Secondly, can you reduce the size of those two pictures above? They are pretty large.

Thanks, Jim.

Congrats on the new vehicle! (What prompted the change?)

I'm looking forward to seeing what you do with the C.

It is good to see you back on the forum again. I look forward to seeing what you have planned, and what kind of mileage you can squeeze from the C.

I'd also like to know what prompted the purchase?

The Prius is a different size because the Prius C is a Prius in name only, literally. It is a Toyota Yaris hybrid with a Prius C nameplate.

Good to have you back! Something that stands out between the profiles of the Insight and the Prius C is the apex of the roof is proportionally closer to the front of the Insight. It looks like the final angle of the roof on the Insight is a tad steeper, as well?

It's good to be back. Also, happy 5th anniversary, EcoModder. I suppose I should make a gift out of wood somehow.

Cider, you're right that the car is based on the Yaris hatch, with slightly improved aerodynamics, different interior, and a smaller version of the Prius' engine. This is badge engineering done well.

Btw, Europe will not get the Prius C. Instead, they'll have the "Yaris Hybrid". This will give us good information on the cost and weight associated with this particular hybrid system.

Neil, a (photoshopped) shot with less perspective in it would allow for more accurate comparisons, but I agree with your assessment. The C's less aggressive rear taper, further aft roof apex, and earlier truncation of the Kammback shape are all compromises to allow for rear seats. As with all cars, I only wish it were four feet longer.

What prompted the change? No one thing in particular, but the combination of the following:
*the need to move larger things
*the cosmetic deficiency of the "teach yourself collision repair on a budget" approach I took with the Insight
*the Insight is a 12 year old car. Not the end of the world, but it's needed service to the HV battery, 12V battery, ground wires, exhaust, and clutch hydraulics this year. I expect that the C won't need anything but scheduled maintenance for half a dozen years.
*Rear seats. Those may become a requirement sooner or later.
*Toyota PSD > Honda IMA. Also, the Prius C can make much better use of a grid charger and/or additional battery capacity than the Insight can.

Congrats on the new car ! What will be the outcome of the Insight ?

That's true, you can check the real world MPGs of both cars right here:
Toyota Prius MPG Reports | Fuelly
Toyota Prius C MPG Reports | Fuelly

When it comes to cost and MPG, the C is a totally different animal.. :p

Wow, Robertsmalls got a prius...:eek: Dont worry, it wont be long before you are approaching 100 mpg in that vehicle too.:thumbup:

Congratulations on your purchase! :)
I was wondering which trim level did you get?

Upper grille block!

http://farm9.staticflickr.com/8210/8...06b7bb9f_b.jpg

I cut a piece of black coroplast to the size and shape of the upper grille. I thought about making a template out of tissue paper, but it proved easy enough to cut it slightly large, do a test fit, and trim as needed.

http://farm9.staticflickr.com/8062/8...440fed39_b.jpg

I wonder how much of the lower grille I can block. I'd like to do a more sophisticated adjustable lower block than I had on the Insight. This would be especially helpful for this car, to reduce warm-up time.

--------------

The car has 300 miles on it now, and I'm getting slightly better than the EPA Combined 50mpg. Weather is autumnal, and the driving has been a mix of highway, suburban, and urban.

Worst FE so far was about 25mpg on a 1.7mi trip to the hardware store today. The engine warms up awfully slowly in gentle city driving. It didn't help that I accidentally left the cabin heater on. This is a route I drive fairly often, so I'll keep working on it.

The engine bay is getting a bit grimy. This isn't necessarily a problem, but it is a symptom of aerodynamic issues:

1. There's an awful lot of radiator area. I'll keep an eye on engine coolant and inverter coolant temperatures, and I'll bet I can block most of the grille.

2. There's a hood gasket, but only between the headlights.

3. The underside of the engine bay is largely open. I'll see what I can do to correct that without drilling too many holes.

A view from the front:
http://farm9.staticflickr.com/8349/8...f0075d35_b.jpg

The (total lack of) underbody panels:
http://farm9.staticflickr.com/8359/8...6d057cdf_b.jpg



I wish this were true. The C is good at many things, but getting 100mpg is not one of them. :(

AJ: I got the Two. I thought long and hard about getting the One, which would have been $1500 cheaper, but the One gets the fleet seats and is missing things like the center armrest, cargo area cover, cruise control, split rear seats, etc.

The lack of cruise control kept me away from the C1. The C2 was the best choice for us.

What do you think of the headlights on low beam?

Please keep us posted on the amount of grill block used.
I might have to add one, if the MPGs start to drop when it gets real cold..

I vote for a full grill block. I was just at the Milwaukee Hybrid Group meet talking with Prius guru Wayne Mitchell (fire engineer on Priuschat) who knows a ridiculous amount about the different Prius' and HSD. The basic consensus of the discussion was for winter do a full grill block unless you are taking a prolonged highway trip, then just pull a tiny part out (we talked pipe foam since that is the most common block type). In summer you might need to open it up a little more, but I think he said he just runs all summer with one pipe foam piece removed. Warm up is critical for good mileage with a HSD vehicle. I have a 7 mile commute and most of my mods are focused on heating the car up and it has definitely helped.

I just looked at the cars and found my Ford has a gap between the two heat exchangers.
(refrigerant & coolant coils)
That allows me to just drop a sheet of Coroplas between the two.
Just like dropping a sheet of paper into a file folder. :D
It's not real cold yet, so I'm starting off with a 30% block.
And will select coolant temp on the SG2.


'C' upper intake:
I noticed a small air-intake duct on the left (passenger) side.
Inside the engine compartment, it exits right in front of the air-intake for the ICE air filter.

It seems to me, the duct is designed to allow cold air to flow around the coils and directly into the ICE air input.
It's a bypass air channel. Should it be left open?

Xringer: I like the headlights. The car comes with DRLs, and lets the driver decide whether to run them or not. I actually use the second headlight setting (DRLs plus corner lights, headlights off) for city driving at night, when you need lights to be seen rather than to see.

Yes, that trumpet thing is the engine air intake. As you can see, it's not positioned to try to take in cold air. For fuel economy, you want your intake air temperature as high as the engine will tolerate. 120°F is a safe bet.

Daox, what time of year do you remove one piece of foam from your grille? How fast can you go / how hot can it be outside with a 100% block?

I saw the little down-pointing 'trumpet' horn on the input to the resonator box-filter path, but what I was referring to, is the little air-duct that you can see on the extreme left end of the upper grill.
It's output is a few inches away from the trumpet horn intake.

I've seen these air inputs on other cars, feeding right into filter input.
I figured they wanted to drive cold air into the filter.

But, if we want warmer air going in, blocking that duct is a good idea.
Might keep a few insects out of the air filter too.

The newer insight had that too. I tucked a water noodle in that gap and in the sumemr in stop n go traffic it makes the ac way colder.

So the c is different than the base 3? I drove it like a rental car, got 49.9 mpg, drove it with some eco sense and got 65mpg. :thumbup:

Just the other day it was 45F out and I was on country roads for probably 10 minutes. The full grill block was fine, no chance of the fan kicking in. I then got on the freeway (60 mph) and probably traveled another 10-15 minutes, and the coolant had gotten up to 204F before the fan kicked in and dropped the temps back down. I then turned the heat on medium and the coolant fan didn't have to turn on for the rest of the drive which was probably another 20 minutes or so.

Our C is a C2 model. Here's the model info.. The Toyota Prius c models and prices

The average C driver gets about 51 MPG Toyota Prius C MPG Reports | Fuelly

Unexpectedly, I got 62.5mpg on the way to work, and 66.0mpg on the way home. I'm impressed, especially for a 45°F day, and driving home with the headlights on. These are numbers that would be only slightly disappointing on an Insight, and there are a few important ecomods left to do on the Prius C.

------------

Perhaps some Prius veterans can chime in here, but this is what I've figured out about the Eco Meter. The Eco Meter is a bit like a tachometer, in that it indicates how hard various parts of the powertrain are working, and how much power the driver has requested.

http://www.autoguide.com/images/cont...Score-0207.jpg

The blue region is regenerative braking. Braking is bad, for obvious reasons.

The first half of the green region is where EV mode is possible. Electricty isn't cheap, so I use it sparingly. If I can extend an engine-off coast in traffic without drawing much power, I'll do it, but the combustion engine should be the primary source of propulsion.

In the first half of the green region with the engine on, the engine isn't heavily loaded enough to be efficient. This is the vertical part of the BSFC curve at 1000RPM. Stay out of this region.

The second half of the green region is where the engine operates efficiently. This is where I keep it during cruise and acceleration.

The last segment is colored red and labeled "PWR". I'm not sure exactly what happens here, but it sounds like trouble.

------------

Biggest peeve: once the car is warm, it will let you accelerate up to 45mph or so without turning on the engine. It has a 1KWh battery, which should be good for at least a mile or two. But I have to resort to trickery to even back out of my driveway without it turning on the engine. That's especially sad because the combustion engine is only a hindrance to rearward progress.

The car is programed to try to get its catalytic converter hot within a certain number of minutes of being turned on. So instead of waiting until I'm on the main road to fire up the ICE, it does it three seconds after you power up the car. For now, I've exposed the shift interlock override so I can park the car in Neutral and pull it out of the garage by hand. Then I start the car, and I have three seconds to get the car rolling backward before I have to be in Neutral. It won't start the engine until I shift to D. I really want the ICE to stay off until I get out of my neighborhood and out to the main road, where it can warm up quickly.

The long-term solution is to trick the car into allowing me to use EV mode right off the bat. I wonder if a coolant temperature hack would do the trick. It would be amusing to repurpose the presently-useless "EV Mode" button for the task.

I'm sure I don't need to ask if there's a good reason why you don't back into your driveway.

Makes more sense to do this when the car is warm and willing to shut off its engine so you can EV mode yourself into your parking space going backwards. Also makes human-assisted launches possibly more efficient going forward (because you don't need to then stop & change direction) ... or, hey - you could reverse your rear tires up a pair of ramps for "launch assist" when it's time to leave!

Tim (Daox) has been working on a coolant sensor hack. I don't know the details, but maybe he'll chime in.

I wonder if a 144vdc battery charger could be used to top-off the pack after you parked in the evening?

So, if you tricked your C into cool-ICE EV-mode, you would have enough juice to get up to main street.?. :)

The coolant hack I have worked on (presently not installed nor working) is not going to do what you want it to. The EV mode is not based on coolant temperature I do not believe (unless you turn the heat on). It is based on pack temperature.

Also, good luck with even getting 1 mile out of your battery pack. Max SOC is 80% and max discharge is 55% on my 2nd gen. That means you get to use a whole 25% of that 1kWh pack. Believe me, you'll pay for it when the engine kicks back on too. It really is best to stay out of it IMO.

Conservation of momentum! I roll onto my street at 15mph, bounce into the driveway at 10mph, and coast to a stop in front of the garage.It's a NiMH pack, same as the Insight's. I don't see any reason why I can't use the Insight's battery charger to charge it. I'll look in to it later.

Daox, I'll try it with a warm engine some time and see what the SG SoC indicator says. The first leg of my commute is 0.3mi, has a top speed of 25mph, and has five complete stops and a red light. I understand why EV mode in a gas-fueled car is generally a terrible idea, but it could work well in this case. One step better would be an ICE kill switch, though. If such a thing does not exist, it needs to.

Good news: I found a copy of the FSM.
More good news: The section on "Hybrid Vehicle Control" is 572 pages.
The ECU has 110 terminals. :eek:

The way I got 15 more mpg was to save ev use for maintaining and coasting. I also rode the brakes to a stop hard enough to fully lite up the brake part of the indicator. I also fully inflated the tires to sidewall psi. :eek:

Ive gotten a lot of nasty emails about my rip of the useless ev switch too on a youtube video I made of my test drive. Infact during the test drive Ive pressed the button several times and got one message after another as to why it couldnt go into it. Then, looking at the screen, half the time it appears the ICE was off and it was on battery and that was even at highway speeds. :eek:

I never let the idling bother me at low speeds. It was explained to me the drivetrain is geared too high for the ICE to drive the car below 10 mph and it was better for it to spin using mg1 to top off the pack and mg2 to move the vehicle and the coolant heating up, blah, blah, blah.

When I go downtown, my first stop light is 1.3 miles down the hill.
When I take off, the C is running first in EV mode, then in mixed mode.
So it seems to be warming up fast.

We've parked downtown (3 miles from the house), picked up items at a store,
get back in the C a few minutes later, hit the EV button and drive about a quarter mile
to the bowling alley on the battery. The EV button works if the car is warmed up
and the SOC is up..

The catalytic converter "light off" is about 45-55 seconds and common to our 2003 and 2010 Prius. One of the best metrics is MG1 torque but you can also see this by watching the mass-flow (or gallons per hour Scangauge II.) The catalytic warm-up phase is an "EV with engine idle" so my strategy is:

• Mentally start a 45-50 second 'clock' to accelerate to a coasting speed.
• Accelerate modestly, use your instruments to keep engine in 'idle' mode. I typically reach 35-40 mph when I am able to shift into "N".
• Park near exit, this allows you to maximize acceleration in this brief phase.

I know 'common wisdom' is drawing on traction battery charge is expensive to replace. In my case, I'm finding the charge is replaced within 2-3 miles and at 45-55 mph, I can't find a significant hit. This is not in any way an endorsement of trying to maximize regeneration which is fuel inefficient. Rather this brief interval is available and can be exploited.

Bob Wilson

Cool front wheel covers on the insight. what'd you use or do you have a link in which they're discussed? (they don't look like pizza pans)

I'm not sure if Mr Smalls did a write-up on his wheel covers. But he showed them to me at GGP a few years back. They're fiberglass cloth, laid up on the wheel (which has only small openings, stock). He attached them to the center caps, so they can be popped on/off relatively easily.

Wow, this month makes 2 full years 'C' ownership.. No recalls yet.
And, every time we drive by a gas station with higher and higher prices, we are thankful.. :)

Just a suggestion but you might consider having the transaxle oil changed. If you do, provide a clean, dry, sample bottle and ask for (and write on table) that you need 1 cup sample of the old oil.

The reason is I had our new 2010 transaxle oil changed with the first, dealer oil change. Testing revealed some left over manufacturing debris, some early wear material, and early loss of sealant in the oil. By doing the early change, these small particles were removed before the differential and other gears had a chance to grind them up into the 'smoke sized' particles found in other Prius samples. But of course, it is your car.

Bob Wilson

Hi Bob,
If that suggestion is meant for me, I'm not sure we have to be worried about the transmission just yet.
Since the Prius C only has about 6,500 miles on it so far.. :snail:

Just the same, I rotated the tires and changed the oil and filter last summer.. :cool:

2 years and 6500 miles? The Honda hybrids caution you about not driving the car and how parking it for more than a month can lead to damage to the battery pack. 270 miles a month on average.

The Prius gets driven just about everyday. Just not too far. :)

The Ford is the one that only gets used once or twice a month.
I have a battery tender connected to it. Otherwise, it goes dead.
Next year the battery will be 7 years old and I'll get a new one.

I think the Escape has got around 7,000 miles on it.. Almost broken in..