Eco_4x4

I just put a leveling kit and BFG 275/70/R18 A/T's on my F150. The shop aired them up to 40, but it killed my gas mileage and after 3 days the tread was already showing wear. The tires say 80 psi max load for load class E. Any one have any recommendations on what psi to set them?

Thanks,
Will

cody6766

I always air my tires up to just shy of their max rating. If the max if 44psi, I shoot for 40psi, cold. That allows for the heating that happens from driving. I've never dealt with 80psi tires, but I'd think 40 is WAY too low.

custm2500

40 PSI is perfect.

MAX has nothing to do with reality. Max is what the tire is designed to hold for it's maximum weight caring.

If you are showing tread wear after three days one of a few things are happening.

1.You eyes are trained to notice a 32nd of tread wear.

2.Your alignment is so bad that you are going to destroy your tires in a week.

3. Or you definition of showing tread wear is they don't look brand new.

My fear would be number two because it is an actual problem. Otherwise you are just letting the idea of 40 psi go to your head. If you have an ECO boost then yes the tires alone will kill your millage. It is well documented that heavier 10 ply tires in the stock size kill millage on the ecoboost.

BassAckwards

40-45psi is fine, and I say this all the time no matter how much heat I catch for it, people just choose to ignore the numbers but even 35psi would be fine on our trucks for a LRE1 tire.

techrep

iTrader: (1)

I run 40 PSI int the winter and 50 PSI in the summer in my BFG's have perfect tread wear @ 45K miles...rotate every 5K with oil change.

Bigbore05

Have the same tired and run 35psi rides great and on a 5.0 no noticeable mpg loss. Tried 50 and wow that ride sucks like riding on stones.

c-one

I've had this setup (level & BFG's) on two different eco's, 11 and a 13. I lost 3mpg no matter how much air pressure I tried. (40-65psi) All I noticed was ride quality. On the wear issue, go get a 4 wheel alignment done ASAP.

Pity7700

just put my second set of 35" BFG A/Ts on. great tires.

first set I had aired to around 45 psi. max rating on tire is 50psi, recommended for my 7700 on door plaque is 50psi in front 60psi in rear.

tread wear wasn't too bad. got 45k out of the tires, slightly over inflated though. center wore a lot more than the outside. center of tire read around 4/32" which is recommended replacement marker, outside read around 6/32" or 7/32" in some areas. talked to my buddy that has an early 2000s 1500 with the same size tire, he has em aired to 35 psi.

this time around I aired them down to 35-40 psi to see how the wear would be. haven't had them long enough to tell yet, I have noticed a drop in gas mileage though.

best thing to do is play around with the numbers a bit.

custm2500

Your truck has a solid rear axle correct? If I am then what is a 4 wheel alignment going to do? You can only get a front end alignment since the rear has no adjustment.

krj10

I have that same tire and they had them aired near max psi and they rode terrible. I aired them down to 37 or so and after almost 4 months I've lost about 1 mpg