Upgrade to 31x10.5, What changed?

[hunterdan]

While the speedometer shows 65, i used a gps to calculate my actual speed to 69-70 mph. With this combination I was able to get around 25 mpg on the highway a few times. Granted I haven't been able to get those numbers in quite a while now, but it is still possible to get decent mileage with 31's and the 3.73's that I have. Your odometer will be off as well. If you want things to read properly, you can calibrate your speedometer using a new speedometer gear (if equipped), or in my case having the dealer program the computer for the tire diameter, which is actually the revs per mile.

Dan

 

[storlied]

How much did your dealer charge you?

 

[hunterdan]

Never felt the need to have it done, I had a hard enough time trying to get prices on a set of 31" BFG's from them, but I assume they would charge an hours worth of labor.

Dan

 

[storlied]

95$......................

 

[Hitchhikingmike]

What would ya'll think of 31"ers on an ex with 3.55:1 rear end gearing? Is that too much?

 

[HahnsB2]

What would ya'll think of 31"ers on an ex with 3.55:1 rear end gearing? Is that too much?

IMHO 3.73 is the minimum for 31s, some people like to suffer though
I can't even stand these 3.27s with 235/75s, it's getting 3.73s and keeping the same size tires.

 

[storlied]

31's? What changed? I want 33's now.

I'm running 3.73 with my 31's... it's okay but I want my torque back.. once I go to 33's.. I'm gearing to 4.56!

 

[joshwho44]

Did anyone else notice a significant decline in fuel economy after switching to 31s? I seem to have gone from 18mpg to 15-16 mpg on the highway after switching to 31x10.5x15s. I didn't really expect the SOHC with 4.10s to suffer so much... My speedometer and odometer are both spot on as well (checked with gps on multiple trips).

 

[storlied]

You might have been mis-understanding your mileage before the 31's if your instruments are right on now. (Much like me also, once I switched to 31's.. speedo was perfect.) Meaning stock, it was off.

 

[joshwho44]

But wouldn't the larger tires translate into the gas mileage increasing rather than decreasing? I only moved up from 255s so the difference in diameter should be about an inch. If I remember correctly it used to read 3mph slow according to the gps... I also know for a fact that the mileage got worse. Driving the same 300 mile trip between school and home, I haven't been able to make it the whole distance without filling up when it used to be a non issue.

 

[turboranger91]

i run 31's on mine and i've checked the speed against gps. at 60 on the dash, gps reads 62. at 65 on the dash, gps reads 71. it's a bit off, but it's not going to make my tranny explode.