From what I recall I lost 2mpg going from 35x12.5 to 37x13.5's. Now I am thinking about 315's and debating Goodyears over Khumo's which are slighter shorter but 10lbs less.

I can't be the only one that cry's at the pump and then that kid from the Simpsons goes "ha ha".

I know 35's aren't actually 35" as most are about 34.8 (+/- .1) and 315's are 34.4-43.6 with a slight increase in width. So the biggest high difference is 1/4".

I know I won't like pulling up to a F250 with 38x14/5's on 20's but I won't be the one holding a card board sign asking to spare change for gas money. I remember when gas prices shot up. I handed the attendant $100 bill and he asked if I wanted to fill it up because he didn't have change and I said no I only have $100.

Anyhow, I can't find the info I want to figure out weight comparisons with rolling resistance. Taller tires take less revolutions but the added weight offsets less rotations. Higher gears require less fuel because of less effort but higher rpm's offsets that as well. My 37's are about 95lbs/ea, going to 35's are 75lbs/ea, 315 Khumo's are 70lbs and 315 Goodyear are 60lbs/ea but $20 more each. So if they both left the train station at the same time which would get there faster? Wait? What?

 

OK, I think I figured out the calculations. I've been going by my Gryphon with 15mpg avg but if I get 325 to 26 gal then actual is 12.5mpg. Please post mileage per tank you get with what size tire. thank you

 

I've heard that goodyear tires just aren't what they used to be. I think people said that they were very soft and the tread life was shorter than expected. If your set on either the khumos or the goodyears, then I would say khumos. My current mpg is around 13.9-14.2 on the computer readout, with the 5.4 and 33s on 20s.

 

Oh, I thought it was a soft sidewall which made it a light off road only MT. I looked at the Nitto Dunes for price and street use as i'd be more likely to play in the mud then sand but the reviews puts in in the 40k for mileage. I have limited slip and still one side is worn more then the other. Which made me wonder why no one cross rotates any more. Do they just assume all tires are directional? I prefer MT as a lifted truck with AT kinda looks silly. I think your 20's = the added weight of my 37's. From what i've read Firestone seems to have the highest user rating for MT but Khumo's are cheaper. My Toyo's lasted a long time but they have literally been going up $10/mo since January.

I have the 5.4l with a 26gal tank also. What is the milage you get per tank? I think I am getting about 350 but will have to wait until I'm empty. I gained mpg switching from foam filter to k&n ( I beleive).

 

Have you looked at nitto trail grapplers? They are a MT that look great, and they have a long tread life (around 50k-60k if rotated routinely). They are cheaper then toyo mts and have a longer tread life. I've never hand calculated my mpg or how many miles to the tank, but my readout gives me an average of around 14.2 with normal driving, so with a 26 gal tank thats around 370 miles a tank.

 

I love my trail grapplers. I deliver pizza so im on the road all the time and they handle great and are very quiet.

 

50-60K? I've been hearing numbers more like 40-50. For my sake i hope you're right because I'm going to be investing in a set myself

 

See if you can find some really narrow tall tires. My dad runs a xxx/85-16 on his truck. It has the look of a tall tire but is still narrow enough to get good mileage. Plus, there are some cheaper tires that have heavy sidewalls for towing.

I wont go over 33" because of my highway gears and the fact that they would be bottoming out quicker in my fender wells while driving in rough areas. I also don't cry so hard at the pump since I'm around 400 mpt with city driving.

 

I've seen some posts of guys getting 60k out of a set. They most likely rotated them every 3k miles and kept them in good shape. If you don't take care of them and don't rotate them often then you might get 30-40k. I think they have a great tread life considering they are an aggressive m/t.

 

Goracer, just wondering if you have changed your diff fluid recently? Said you were getting uneven tire wear from side to side. The passenger side will typically wear faster as the crown of most roads will put more of the weight on the right side. but it could be a sign of other things. Anyways I noticed a increase in mpg after changing my diff fluid this spring. I went with RP but i think you could benefit with any quality dif fluid and fric modifier if yu have a lsd.

 

I hope i can get that out of mine when i put them on in a couple weeks. It wont upset me to get 60k from them.

 

Deliver pizza in a 4x4? Gas would cost more then sal' + tips.

Tall skinny tires on lifted truck? No, the only reason I went with 37's is Toyo's are 13.5 and I believe their site lists them as 14.5" wide. I would have been terrified of a rollover with 37x12.5's and 7" lift.

I change fluids (redline or amsoil) every 1-2 years except the front diff every 3.

I put the deposit down on the Khumos. With inflation increasing prices $5-$10 a month it's cheaper to buy them now then wear out what's left of the Toyo's. I decided 315's were the best choice. I could not justify $200 more for 35's. I know people think 35's are 35" tall and 315's are 34.5" but neither is true. Most 35's are 34.8 (can be shorter) and most 315's are 34.6 (+/- .2). In this case I traded .2 of height for +.2 of width.

So I filled up today and figured 13.6mpg. My speedo is +3 at 65mph. So that's not taking in to account the 1% (I think) error. I can get 14.6 without the A/C and 15.6 mostly long highways. My Gryphon reads 18.6 avg going to vegas but I can't afford that anymore. I am hoping to get +2mpg back.

I almost got the Goodyears but waited too long and lost the sears discount and rebate. It's rated really well in rain and snow but gas is too much to hit the snow, uhg.

I think I got 50-60k from the Toyos and the previous Procomp's were 25-35k as they cupped really bad, even with rotation.

 

actually its a 2wd

 

I think most people would be happy getting 14-15mpg on 37s. I'm getting 13mpg on my 265/70r17s and once the lift and 35s go on I'll be happy if i get 11mpg until new gears and the edge evo are put in.