Extra credit for EV or regen braking?

Dark_matter_doesn't · 09-17-2009, 12:47 AM

I've noticed that the displayed digital MPG ("cons.") value seems to increase most often when I'm in regen braking. I don't see the value increase as frequently while I'm driving, mainly when I'm braking.

Could the algorithm used by the vehicle for calculating MPG be giving "special credit" for regen braking & energy recovery? Perhaps this is the reason why the vehicle-displayed MPG values are always a bit higher than the fill-to-fill calculated MPG values - the fill-to-fill values don't count the energy gained & stored in the battery.

qbee42 · 09-17-2009, 10:04 AM

No extra credit. The mpg calculation is simply distance divided by the fuel consumed during the calculation interval. If you are running in EV or coasting, little or no fuel is consumed, meaning a higher mpg. In the case of EV, you pay for it later when the engine recharges the battery.

Tom

09-17-2009, 12:47 AM	#1
Dark_matter_doesn't Member Join Date: Aug 2009 Location: Seattle, WA Posts: 93 My Car: 2010 Prius Model: IV Package: Solar Roof Thanks: 25 Thanked 27 Times in 13 Posts Friends: 0	Extra credit for EV or regen braking? I've noticed that the displayed digital MPG ("cons.") value seems to increase most often when I'm in regen braking. I don't see the value increase as frequently while I'm driving, mainly when I'm braking. Could the algorithm used by the vehicle for calculating MPG be giving "special credit" for regen braking & energy recovery? Perhaps this is the reason why the vehicle-displayed MPG values are always a bit higher than the fill-to-fill calculated MPG values - the fill-to-fill values don't count the energy gained & stored in the battery.

09-17-2009, 10:04 AM	#2
qbee42 Senior Member Join Date: Mar 2006 Location: Northern Michigan Posts: 10,480 My Car: 2006 Prius Model: Package: #7 Thanks: 95 Thanked 391 Times in 290 Posts Friends: 10	Re: Extra credit for EV or regen braking? No extra credit. The mpg calculation is simply distance divided by the fuel consumed during the calculation interval. If you are running in EV or coasting, little or no fuel is consumed, meaning a higher mpg. In the case of EV, you pay for it later when the engine recharges the battery. Tom

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