Coolant Temperature Hack. Better MPGs!

when i pres the EV button right after hitting the power button it Will not start warming up
only after the SOC drops below 45 or something then it starts and begins to warm up
at that point i can shorten that startup with this mod..

 

You gotta be kidding me! Over what distance, terrain and driving conditions did you achieve that? If one can consistently achieve 200 mpg in a Prius simply by falsifying the engine coolant temperature, then I would presume this would grossly outweigh the environmental advantage of keeping the catalytic converter hot to reduce emissions.

Thus, I'm skeptical you could consistently achieve even half of that mpg (100mpg) with this mod under typical driving distances and conditions. Perhaps you could significantly boost your MPG this way if your commute was very short. But why go through all the trouble, when an engine block heater would provide the same benefit for a couple pennies on the mile?

Those engineers at Toyota are a pretty smart bunch, and I'm sure they experimented with different thresholds of temperature control before arriving at the present system.

I'm very interested in this entire issue of temperature control and modes. My own commute is just 4 miles of flat terrain with about 10 stop signs or traffic lights, speed limit 30mph (which I exceed a bit in order to pulse and glide, when possible). Before my scangauge, I would average about 48mpg. With the scangauge, which provides me better awareness of engine status and modes, I now average about 53 mpg. My coolant temperature doesn't achieve the target 185 degrees until the end of my 4 mile commute. Last night I did a simple experiment --- I drove to work, then turned right around and came back. With the engine completely warmed up and in Stage 4, I achieved 85 mpg on the return trip. Based on that experience there is absolute no way I could achieve even over 100 mpg with either a truly warmed up engine, or a faked-out coolant temperature.

 

Well, there's a little more to the story. He also recently had installed a plug-in conversion with an additional battery, described in this thread. That's where most of the improvement over the fuel economy achieved by us mere mortals comes from. The hack helps more fully exploit the conversion's capabilities.

 

cool mod, but since i did not buy the Prius to reduce my gas bill. i will pass.

this just makes the Pri pollute like a reg gas car until warmed up.

 

old cars did not run with higher fuel to warmup faster so maybe this hack/mod is not that bad for the prius engine?

 

not bad for engine im guessing since engines have run this way for years and still do. just bad for environment. so what is worse? lower gas mileage or slightly more pollution?

if there are independent sensors in the exhaust stream, it might not be so bad after all, as the car may still be able to sense unburnt fuel and be able to recycle it anyway

 

sure your not going to contact Hymotion? P1600??

 

ok is the hymotion pack taking more standby current from the 12volkt batt. when the car is turned of?

 

Here is a neat video you can see this guys coolant hack and also some neat looking gauges..

[ame="http://www.youtube.com/watch?v=e-o3qtq3NUs"]YouTube - CNN : Eco Solutions : Hybrid Hackers[/ame]

 

Those gauges look like the Super MID gauge made by Yoshi. I'm jealous since I see he has 3 strung together and 2 is the maximum for the Scanguage.

My coolant hack is working great so far. Somewhere, the concern was brought up of the engine running lean since the coolant temp is being faked. I have a question about that: Wouldn't the O2 sensors sense the lean condition and call for the injector pulse width to increase?

 

Thanks for the link Jay, I think I'll bookmark it. For the most part, 2 gauges is about right but there are those rare occasions when I want to monitor another parameter or two.

My guess is you could probably fit 6 or more SG's on the dash if you were creative in how you positioned them. Not that I've measured or anything like that.

 

nice and funny video . like it!

 

Any problems running the two together?

 

When the car is running closed-loop (probably immediately after the S1 warmup) the answer is likely yes. When it first starts, the O2 sensors do nothing so it would not know to adjust the mixture. Maybe you should configure the SG to give you the open loop/closed loop display and only start using the hack after it reads closed? I **think** that you would be good-to-go as far as mixture is concerned.

 

and?
after a while can you tell if your still using it?
and no problems?