something interesting from EPA

[gone-ot]

...a new page on the EPA Fuel Economy website:

• Fuel Economy: Where the Energy Goes

[Ladogaboy]

I've seen this before. I think it's been up for at least a year or two, but I kept for getting where the info was.

[Sven7]

Cliffs:

It also gives you a little more info on each bit... but you'll have to go to the site to see that!

Fuel Economy: Where the Energy Goes

Only about 14%–26% of the energy from the fuel you put in your tank gets used to move your car down the road, depending on the drive cycle. The rest of the energy is lost to engine and driveline inefficiencies or used to power accessories. Therefore, the potential to improve fuel efficiency with advanced technologies is enormous.

[mort]

OK, so is this believable? At highway speed 10% to 15% of the fuel goes to tire rolling plus drive train? LRR tires are supposed to be around 1% drag, if the engine is 30% efficient that's about 3.3% of fuel energy. Are standard tires 2 or 3 times worse?

-mort

[Ladogaboy]

Maybe, but isn't 30% rather generous for engine efficiency?

[mort]

Originally Posted by Ladogaboy

Maybe, but isn't 30% rather generous for engine efficiency?

Hi Ladogaboy,
I know, but the EPA graphic (highway) says "Engine Losses: 65% - 69%"

-mort