Relation to fuel-economy vs Vehicle Resistance

sometimes the seemingly 'cheap' materials can be problematic. but when you put it in the context of higher fuel efficiency, it makes it all the more worthwhile.

 

That's funny I was just looking for a place to plop this equation I stole from the Chevy Cruze chats.
My intent was to post this this on the spare tire thread but I will offer it here.
Think it says +50-lbs is -0.6 MPG at 50 MPG for 3165 car weight (PiP).

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time to start yanking out all the extraneous parts!

 

Bisco-I think we should just simplify to say this "GM" equation predicts -1 MPG per 100 lbs.
(which is maybe what someone else already posted - but at least we have some theory behind it)
Somebody check my math.

 

With the regeneration in the Prius (plug-in or standard), why is there a connection between mpg and weight? For conventional cars, it the additional energy needed to accelerate additional mass is lost when you slow down.

 

can you elaborate charles? i'm not following, thanks!

 

If regen was 100% effective, weight may not be a factor in MPG. As it is about 30% effective (compared to 0% in other cars) it still hurts MPG to slow down and speed up again with electricity. Much better to coast to a stop if you have the time.

 

aha! thanks.

 

Charles/All- Good points. Obviously it would be best if someone here had a friend in Toyota and we could get the exact equation from Toyota engineer for Prius. Not having that Toyota input, I managed to Google a GM engineer equation.

We can accept Jimbo's idea that Prius may be ~ = 70% x GM value, until such time as we get Toyota equation. Should we here be more proactive in asking for Toyota engineer assistance for some of our questions??

 

I think it would be really cool to see the Prius Team here. I've seen them in the Gen 3 forums.

 

How technical is PriusTeam? My understanding is that this is essentially the Prius product management team for Toyota USA, so at best, they would have contacts to the engineering team in Japan for technical questions. PriusTeam had a significant presence in the PlugIn forum during the rollout of the pre-orders.

 

Yeah, I mean, they have more contact with engineering than any of us lol.