View Single Post
Old 11-18-2019, 04:35 PM   #7 (permalink)
Hersbird
Master EcoModder
 
Join Date: Feb 2014
Location: Missoula, MT
Posts: 2,668

Dark Egg - '12 VW Touraeg
Thanks: 305
Thanked 1,187 Times in 813 Posts
Quote:
Originally Posted by Taylor95 View Post
https://jalopnik.com/what-kind-of-fu...1839901794/amp

Despite some inaccuracies and bad comparisons I noticed in the article, it explains well that engine efficiency plays just an important part in fuel economy as coefficient of drag does. So some cars that are shaped like bricks (my Jeep) can still get good FE without making too many concessions to aerodynamics. Not something too many ecomodders consider as most cars here have small engines and have a fairly low cd already.
They used .22 as an engine efficiency in the caculator while claiming a .4 engine efficiency in the article. 40% must be "peak" efficiency not seen at 50 mph.

I was going to try and see how reducing engine efficiency while leaving the aero good to see what effect that had compared to the aero. You have to take efficiency down to .105 to get 29 mpg. I don't know of any properly functioning ICE that is quite that bad. Take the speed up to 70 and run the same numbers and the aero is now a 40% worse penality than thermal efficiency.
  Reply With Quote
The Following User Says Thank You to Hersbird For This Useful Post:
Xist (11-20-2019)