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Old 03-03-2010, 08:46 AM   #22 (permalink)
RobertSmalls
Left Lane Ecodriver
 
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Join Date: Aug 2008
Location: Buffalo, NY, USA
Posts: 2,257

Prius C - '12 Toyota Prius C
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The car leaves the factory with a stratified charge lean burn scheme, that allows AFR as low as 22:1. It happens automatically when the catalyst is warm and the engine is lightly loaded, and the driver notices, because less power is produced at the same throttle position. Also, the fuel economy gauge shoots upward when you enter lean burn mode.

I'm sure Honda used EGT and NOx sensors while developing the engine, but the car only needs a wideband oxygen sensor and lots of emissions equipment as a result of lean burn.


Having a fuel economy gauge is very helpful, but a fuel economy gauge will tell you heading down a hill at very high speeds is good, braking is not bad, and heading up a hill at full throttle is bad. We know all these things are untrue.

I'd like cars to come with a BSFC gauge, and a road load gauge. The BSFC gauge would tell you how efficiently you're producing power, and the road load gauge would tell you how much power you're using. Although your project doesn't (yet?) give the output in real-time, it would still improve my driving.


I would like to install one of your boards in my car. Perhaps I can help find where your road load model deviates from reality.
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