The Prius Experiment

[Phase]

Originally Posted by Caddylackn

I have thought of making a curtain of old CDs or DVDs glued to a piece of sheet that I can just pull a string and it comes down by the back window. Blocking their headlights from blinding me and throwing 100% of their bright lights back at 'em.

No way they won't get the hint.

Or just tint the rear windows?

[Blacktree]

Just a quick update. We now have 2 fillups since adding the CeraTec to the engine and transmission. So far, the results look promising. Actually, the last fillup was a new personal best! It came out to 65.9 mpg. Previous to that, the best was 63.6 mpg, back in April.

I haven't done the math yet, to see if the FE increase is enough to cover the cost of the additive. That can wait until I get more FE data.

Also, we have another tropical storm (possibly strengthening to a hurricane) coming our way. So the projects are on hold... again.

[hayden55]

Originally Posted by ps2fixer

I see, I'm actually working on an engine simulator to test stock computers, would be interesting to simulate engine knock (knock sensor) and see if it only pulls ignition timing, or timing + adds fuel. I don't have any computers from an engine that had boost factory though. Would be interesting to see the data on it though.

Reading back through before i asked a question. But yes the ls400 pulls ignition timing for 87 vs 91 etc... (power difference is 5whp and around 0.3s in the quarter mile) It for sure knows the difference through the knock sensors. I get the same mpg with normal cruising with 87 octane. 87 is the minimum octane requirement and 91 octane is the octane the car is legally required to be stated is the octane it was rated on to achieve its numbers with.
But WOT and staying in open loop the whole time with mountain pass spirited driving in the ls400 there is a big difference in fuel economy. I get like 14mpg on 87 and 17mpg on 93 with the ls400. And yes you typically need to run around 11.0-11.5:1 with boost vs like 12.5-13.0:1 with NA apps on E10. So it gets to be very wasteful. You will melt the combustion area components if you go too lean and blow the motor. I did see that lexus runs the ls400 rich at wot to give it better reliability though. (like 12:1 ish at wot, closed loop is not the same as it runs at lambda in that mode). So yeah if you wanna learn some more about look at some HPA videos on youtube on tuning, join the efi tuners guild on facebook, etc...

Back to prius stuff though. Blacktree have you monitored oil consumption on your Prius? If it has any you should try the magic corn juice and do a piston soak. Its insane how well it works at dissolving oil sludge, fuel varnish in old fuel tanks, engine degreaser, fuel injector cleaner, etc etc... Its insane. I used it recently to clean the oil pan, fuel lines, and gas tank on an ls400 that sat for 13 years recently and it all just melts away instantly. I wouldn't leave it in too long around rubber stuff though as e85 is still just alcohol so its kinda rough on rubber if it touches rubber for a long time.

[Blacktree]

Originally Posted by hayden55

Blacktree have you monitored oil consumption on your Prius?

Yes. It consumes about 0.5 liter between oil changes. And I change the oil every 5000-5500 miles. I've been told these cars are known for burning oil, but I must have got lucky.

Side note: I did a quick estimate, and it seems that in my case the Ceratec would need to add 2 mpg to pay for itself. That assumes the car had 60 mpg before, and the gas price is $3 per gallon. It also assumes the Ceratec additive will last 30k miles (which is what Liqui Moly claims). But those are just estimates. Real world results may differ.

And for anyone who is following along, the "break even point" for you will differ based on your existing fuel economy and the price of fuel in your area. But generally speaking, the lower your FE and the higher the gas price, the more likely you will see a benefit.

[hayden55]

Originally Posted by Blacktree

Yes. It consumes about 0.5 liter between oil changes. And I change the oil every 5000-5500 miles. I've been told these cars are known for burning oil, but I must have got lucky.

Side note: I did a quick estimate, and it seems that in my case the Ceratec would need to add 2 mpg to pay for itself. That assumes the car had 60 mpg before, and the gas price is $3 per gallon. It also assumes the Ceratec additive will last 30k miles (which is what Liqui Moly claims). But those are just estimates. Real world results may differ.

And for anyone who is following along, the "break even point" for you will differ based on your existing fuel economy and the price of fuel in your area. But generally speaking, the lower your FE and the higher the gas price, the more likely you will see a benefit.

Oh you're good then. I wouldn't worry about messing with a car that only consumes essentially a quart every 10k. thats A- territory. Just keep the pcv system loop cleaned up and kink free and you'll be as good as it gets. And keep changing the oil every 5k or less.

[Blacktree]

OK, the LiquiMoly video is up! The conclusions probably won't be a surprise to anyone.

https://www.youtube.com/watch?v=BRUxs9zw5K4

Also a side note: lately I've been hearing some noise from the front end. Sounds like a bad wheel bearing. I can't really tell from the driver's seat which side is making the noise. But I think I can put a mic in there and drive around a bit, to find out. So I bought a wheel bearing / hub unit. And I'll install it as soon as I know which bearing is bad.

[hayden55]

I would say your testing conditions have a real world error of a handful of percent. So it would really be impossible to test if that stuff really worked with such a low percent change. Maybe if your car got 50.0mpg evey month of the year it would be more verifiable.

Yup check your caliper slide pins, slide clips, clean and lube if necessary, check the boots on the halfshafts and make sure they aren't leaking and creating a dry or dirty noisy axle, pull on the hubs up and down and check for play.

[freebeard]

Hard cornering to the left and right might be enough to point one way or the other.

[Blacktree]

Originally Posted by hayden55

I would say your testing conditions have a real world error of a handful of percent. So it would really be impossible to test if that stuff really worked with such a low percent change. Maybe if your car got 50.0mpg evey month of the year it would be more verifiable.

I tend to agree. The driving conditions are not as consistent as I would like. Plus we have things like changing seasons and occasional maintenance issues skewing the results. Also, this method of testing fuel economy takes a long time.

Most of the mods I'm doing are aerodynamic. So I think it would be a good idea to try some coast-down testing.

[Xist]

Hey, impressive results!

I just fear that mechanical issues are eating your savings!

I have been here a while and people have tried various ways to attach wheel covers. Several members have simply zip-tied the covers to the wheels, which never lasted long.

Vekke made some plastic caps that I tried, but they were too fragile, and so were the zip ties.

They sell various types of zip ties, so maybe some are UV-resistant, which may not matter if your covers have sharp edges.

I liked this idea, which dates back to the days of Kmart: https://ecomodder.com/forum/showthre...orn-14306.html

I think that I did buy some lug nuts to try it, but they were surprisingly expensive at a parts store.

Someone suggested grabbing them from a junkyard, but the other problem is drilling into a lugnut.

I am sure that it would have worked much better had I started with a punch, but I didn't think of it, and it didn't go well.

Members with cars with steel wheels, used resin and old t-shirts to make smooth wheel covers. Supposedly this site will ship 4 Prius covers for $70: https://suburbanwheelcover.com/
https://ecomodder.com/forum/showthre...vex-14958.html

Metro glued pieces of plastic to his wheels to fill in the gaps, but they fell out.

You have done more ecomodding than I have and I have been here longer than most!