Gas prices are going to make me bankrupt!

[Ky strutt n bust n]

It is getting alittle pricey.  I made the mistake of going to ATs when I wore out my stock tires and dropped to 15mpg from 17-17.5(GMC 4x4 5.3L).  150 mile round trip to the camp and I'm only getting around 13-14 when hunting. Fun fun.

Ronnie I'm running AT's as well.  Thats what came on it and its what I've always put back.  When it was new I was getting about 21-22.  Now with all gas stations here selling 10% ethanol I have dropped to 17-18.  I wish I could switch to Highway tread but most of my places require 4x4 to get to if its the least bit wet.

Mine came with the 20" aluminum wheels and 275/55/20 GY LS2 street treads.  I put 80K on those tires, but bumble bee spit on green grass would call for 4x4.  I pulled them and put some Cooper Zeon LTZ ATs of the same size on her and the mileage went down the tubes.  15mpg HWY is a bummer with today's prices.  I put around 25k+ on one every year, so it would probably be worth it to chunk the new tires and go back to a less aggressive tread. I'd prob save the cost of a new set of tires in less than a year.

Talked to someone that had Pirelli ATs of the same size and he said his mileage was good, but the tires did look like street treads.  The LTZs are darn near like mud grips.   I used to get 18-19 on trips with the LS2s and even logged 21-23 on a trip to WY.  This year I never broke over 16.9 and mostly around 16 on my hunting trips.

The key to getting decent mileage out of an aggressive tire is run the tire pressure as close to max PSI as possible, without causing too much wheel hop.  Light truck tires, especially the D and E range tires, can run max PSI up to 65-80lbs.  Running them below 40 will add a lot of rolling resistance and chew into your mileage.  I'm running 285/75/16's Nitto Terra Grappler E's on a 1/2-ton Silverado...not ideal, I know, but I'm running 55 PSI in the front and 45 PSI in the back, and I'm getting 18-19MPG (adjusted) on the highway.  Any more pressure in the rear, and she gets a little scary with the bunny hops on rough pavement.  Taking them down to 40 PSI yields only about 15-16 MPG.

will the tire wear be uneven if you boost up the PSI like that?

thats kind of what i was thinking? i just took mine to get balanced and rotated and i had 45 psi in all mine(31.5x70x17's) and theyre terra grabblers. they took mine back down to 35 psi. idk why but said 45 was to much. haven't noticed no gas mialge change

[stinkpickle]

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The key to getting decent mileage out of an aggressive tire is run the tire pressure as close to max PSI as possible, without causing too much wheel hop.  Light truck tires, especially the D and E range tires, can run max PSI up to 65-80lbs.  Running them below 40 will add a lot of rolling resistance and chew into your mileage.  I'm running 285/75/16's Nitto Terra Grappler E's on a 1/2-ton Silverado...not ideal, I know, but I'm running 55 PSI in the front and 45 PSI in the back, and I'm getting 18-19MPG (adjusted) on the highway.  Any more pressure in the rear, and she gets a little scary with the bunny hops on rough pavement.  Taking them down to 40 PSI yields only about 15-16 MPG.

will the tire wear be uneven if you boost up the PSI like that?

As long as you're not running them higher than the max cold pressure listed on the sidewall, you should be fine.

[stinkpickle]

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thats kind of what i was thinking? i just took mine to get balanced and rotated and i had 45 psi in all mine(31.5x70x17's) and theyre terra grabblers. they took mine back down to 35 psi. idk why but said 45 was to much. haven't noticed no gas mialge change

They might be basing that on the suggested tire pressures listed for your vehicle.  If your Terra Grapplers aren't stock (I'm assuming they aren't), just look at the max cold pressure value on the sidewall.  Either way, you may not experience much mileage difference between 35 and 45 PSI, but when the sidewalls on my TG's show any flex (around the 40 PSI mark and under), the mileage sinks.  You'll just have to experiment.