Quote:
Originally Posted by wyatt
I will have to check what the tires were when I get back home, and report back. I do know the rims were 8" wide, vs the 7" wide Prius rims. The rim/tire combos are noticeably lighter when lifting. This is comparing between my wife's 15's and the 17's. I don't have a mass reading on both, so it's not a real comparison, but it is something I noticed.
Running the old tires on the back of the car would be an option, but we plan to sell off the 17" rims to someone looking to "upgrade" their ride. Anyone here looking for some 17's? 
I agree, it could be a large number of factors that impacted the large change in FE. I am just glad it is up, way up . |
I'd weigh each of the wheel/tire combos. I think you will find the 17s are heavier by a few pounds. Each. I mention this because I've been looking for some different wheels for my truck. Factory 20s are 42# each, I'm told. Just the wheel itself. I plan to pull one off sometime and put it on the scale. (by the way, my factory tires are 42# each also!)
My tires have 51K on them, but weighing should give me some sort of idea. I can get some 20" Centerline forged wheels that weigh 26# each. Their 20x8s weigh 26#, 20x8.5s weigh 28#! A lot of guys on DodgeTalk that race their trucks switch to 17" wheels to save weight (and reduce their gearing). Factory 17s for my truck are about 27# each...without tires installed.
Rotational weight is an ecomodder's enemy.
On Ecopia tires, we just put a set on the wife's Avenger. Supposed to be really good. Firestone says we'll save over $300 in fuel over the life of the tires. I've pumped our tires up too; they only inflated them to 29 psi? Car says 32. I'm thinking I'll go with 35. Didn't want to replace the old tires (only 46K) but I hit a piece of metal that cut half-way across the tread on the left rear. Fortunately it was a slow leak; not a rapid puncture. The car's steering is noticeably lighter with the Ecopias.