View Single Post
Old 12-22-2012, 05:15 PM   #4 (permalink)
ever_green
Master EcoModder
 
ever_green's Avatar
 
Join Date: May 2011
Location: Toronto
Posts: 264

gueff - '19 Mercedes Benz A250 4MATIC AMG
90 day: 30.55 mpg (US)
Thanks: 8
Thanked 79 Times in 33 Posts
I would focus more on coasting than acceleration. from my experiments (i just posted a thread) differences between 60% or 80% load acceleration are minor, specially for long distances (ie. merging onto a highway). for shorter distance such as 2 stop signs 300ft apart i would use as little engine load as possible.

i have a 4.11 final drive on my subaru and my rpms are a tad bit high -> 3000rpm at 70mph. however my engine load is fairly low at that speed, only 40%. with this i can easily get 37mpg easy just by using cruise control. so for cruising i think lower engine load is better as well, but again this is for my car. i know alot of auto enthusiasts swear by high load and lower RPM but that hasn't been the case for me in the real world. my car has an oversquare engine design which makes it rev happy. your 4.6 is a square design which i'm not sure about. my v6 TL is square and likes 1800rpm with 40% load. so it depends on the car but a 4.10 axle will surely degrade your fuel economy. At the same time 4.10 axle will make the car better performance wise. i would get a 4.10 axle for towing and 3.55 for fuel economy.
__________________

Last edited by ever_green; 12-22-2012 at 05:55 PM..
  Reply With Quote