A/T Tire question

[nate1dawgg]

I am a complete noob when it comes to tires. I've been trying to research them with all the great info on this site, but still needing some help. I'm in need of replacing my stock tires soon and would like a little info. I'm running 265/65/18 right now and would like to keep that size, at least until I'm able to buy a BB tune. I'm looking at the Cooper A/T3's in that size. My question is what kind of MPG hit am I going to take if I get the P rated tire and I'm running 3.08's. Am I going to see a loss of power with that tire weight increase and those gears?

[TooTall1]

A "P" rated tire isn't heavy like an "LT" tire. MPG shouldn't change much if at all. Even a heavier tire really only affects mileage in stop and go driving, once the tire is at speed it's no different with a heavier tire. An object in motion tends to stay in motion.

[nate1dawgg]

Thanks for the reply TooTall1. I'm still a few months from buying tires, but thought I'd get some research in now.

[kstruckcountry]

A "P" rated tire isn't heavy like an "LT" tire. MPG shouldn't change much if at all. Even a heavier tire really only affects mileage in stop and go driving, once the tire is at speed it's no different with a heavier tire. An object in motion tends to stay in motion.

This. I went to LT tires and lost no MPG. Even if I had lost mileage it would be worth it to avoid flats for me. But if you don't need LT tires even a P rated all terrain will make the truck a lot more usable.

[nate1dawgg]

But would I lose anything (power, MPG, etc.)having 3.08 gearing? What are the differences between P and LT? Again forgive me, tires are way out of my knowledge.

[Big Whiskey]

Without going into too much detail....an LT (light truck) tire is more heavy duty than a P (passenger) tire. LT tires are stronger, which makes them more resistant to punctures and makes them able to haul heavier loads than passenger tires. However, LT tires are also heavier, more expensive, and do not ride as softly as passenger tires. If you buy those Cooper AT3's your're looking at...and stay with a P-rated tire of the same size...you shouldn't notice any difference at all in regards to power or MPG.

[TooTall1]

However I did notice that the Cooper AT/3's have a tread depth difference between the LT and P versions. In the LT285-70-17 the tread depth is listed at 17mm, while the P version of the same tire is listed at 13mm tread depth. I'm having a set of LT285-70-17's installed tomorrow!

[nate1dawgg]

Turns out there's not even a LT in that size

[TooTall1]

There is a LT285-65-18 in the AT/3

[nate1dawgg]

Ya, but I'm looking to stay stock for now 265/65-18

[Big Whiskey]

However I did notice that the Cooper AT/3's have a tread depth difference between the LT and P versions. In the LT285-70-17 the tread depth is listed at 17mm, while the P version of the same tire is listed at 13mm tread depth. I'm having a set of LT285-70-17's installed tomorrow!

Just FYI, tire tread depth is measured in 32nds of an inch, rather than millimeters. So, the LT tires you mentioned would have 17/32" and 13/32" tread depth, respectively.

 

Turns out there's not even a LT in that size

If you're wanting a LT tire, then run what I'm running....LT275/65/18 in Load Range C. You'll get the added strength of an LT tire (6 ply rating, vs the 4 ply rating of the factory passenger tires)...as well as the extra tread depth (like TooTall1 mentioned)...without much added weight or negative effects on drive-ability. They're only a little larger than stock, and not as heavy as a Load Range E (10 ply rating) tire. My MPG is still on par with stock....although I do have 3:42 gears.

[KMGZ400]

The rating of the tire will not affect how powerful it feels at all.. Get what suits your needs. Changing the size is a different story

[TooTall1]

I had my LT 285-70-17 Cooper AT/3's installed yesterday! I'm loving them!

 

The Rod, thanks for the clarification on the tread depth, the Cooper stat page just used the 17 or 14 numbers, and I assumed it was millimeters.

 

I'll try to get some pics soon!

[kstruckcountry]

I hope your coopers do as well for you as mine are doing for me. Really happy with mine.

[nate1dawgg]

Thanks for all the info!