Bigger Tires + MPGs

[Snap65]

What size did you upgrade to and what's your MPG?

Me:
Stock tire for 16" I got 16 city/22.5 hwy.
Currently with 255/70R16 I get 14.5 city/20.3 hwy.

 

[FLOffroad]

255/60R18 Grabber AT2s - I get about 19-21hwy.

I don't do hardly any city driving, so I can't really say -- somewhere in the 15-17 range (I'm really light on the gas).

 

[GSU4x4]

265/70R16 Grabber AT2s - I get about 13 city & 17 hwy

gas mileage sucks...that's why I'm looking into buying a small car soon to drive the majority of the time

(btw thats rarely going about 2.5k rpms)

 

[swshawaii]

Mileage adjusted from the stock tire size? Not huge, but it adds up.

http://www.miata.net/garage/tirecalc.html
http://www.1010tires.com/tiresizecalculator.asp - Canada

 

[colintrax]

^^ you need to accelerate fast enough to get to 5th gear. The more time you spend in 1st gear, the more gas you waste. Don't be afraid to spin 3k if there isn't a red light or stop sign coming. Just don't rev past 3, that's about the point you start wasting gas to accelerate

 

[eppd00]

On my 08 STA 4.6, I went from the stock 255/50R20 Pirelli to a 275/55R20 Michelin. The stock diameter was right at 30" and the Michelin is right at 32".This has the truck reading about 5mph slow before correcting the speedo,thus increasing mpg. Essentially it changed the ratio down to about 3.25-3.31 from the stock 3.55 or thereabouts. I lost a little on acceleration ,but not enough to complain about. On the highway, flat terrain, mileage is usually between 24 and 27 running 65-70(no cruise control). Start climbing hills etc it will drop to 21-23 but it will pick back up on level roads. Combination, it will drop to 19-21, if you don't get hung up in traffic and do a lot of idle time, then it will really drop.
For what it's worth, gas mileage is very good compared to what I used to get with my 01 and 05 Tracs. Never more than 21mpg with either one. The problem with both of them was the 4.10 gear that I ordered to get the locking rear.(not available from the factory with the Gen.2 Trac). My 97 Explorer with a 302 and 3.73 gear doesn't compare with the STA mileage wise either. Best i ever got out of it is 21-22.

 

[fedyfedz]

.

 

[BigV]

On my 08 STA 4.6, I went from the stock 255/50R20 Pirelli to a 275/55R20 Michelin. The stock diameter was right at 30" and the Michelin is right at 32".This has the truck reading about 5mph slow before correcting the speedo,thus increasing mpg. Essentially it changed the ratio down to about 3.25-3.31 from the stock 3.55 or thereabouts. I lost a little on acceleration ,but not enough to complain about. On the highway, flat terrain, mileage is usually between 24 and 27 running 65-70(no cruise control). Start climbing hills etc it will drop to 21-23 but it will pick back up on level roads. Combination, it will drop to 19-21, if you don't get hung up in traffic and do a lot of idle time, then it will really drop.
For what it's worth, gas mileage is very good compared to what I used to get with my 01 and 05 Tracs. Never more than 21mpg with either one. The problem with both of them was the 4.10 gear that I ordered to get the locking rear.(not available from the factory with the Gen.2 Trac). My 97 Explorer with a 302 and 3.73 gear doesn't compare with the STA mileage wise either. Best i ever got out of it is 21-22.

I also went up to a 275 but I got a 45 profile not a 55 to keep it stock height.