Tires: P vs LT-rated ?

Assuming the same size, which ones are more appropriate for my Toyota Tundra

4x4: P or LT-rated? I haul a load quite infrequently. I also have infrequent (and mild) off-pavement ventures. Wet/snow performance is important, as well as dry, needless to say, on a year-round tire. (I am considering Bridgestone Revo 265/75R16 for now which comes in both versions.)

  1. P-rated are cheaper and, since I rarely carry a load, seem appropriate. But how about the wear characteristics? LT has somewhat deeper tread which suggests longer wear, but does it give me that much of it to justify the extra cost? Deeper tread is also better for snow/wet traction, I assume (for awhile, at least, until it wears even with a P-tire).

  2. On the other hand, since LT is designed to carry a load, it must be more rigid, thus producing more noise/vibration. I am about as much concerned about ride comfort on dry as the wet/snow performance.

  1. Which one of these has smaller rolling resistance, i.e. gives me greater MPG and by how much?

Thanks in advance!

Reply to
J.Smith
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The Revo is an awesome tire and will give you great wet/snow traction. They are the highest rated AT tire out there. You would be best to go with the 'P' rated Revo's for what you want, or if you really want to get LT tires, get the 'C' load rated ones. They are the best compromise between durability and ride. I don't think either one will make more road noise than the other, that is mostly determined by the tread design. I have LT265/75/16 'D' rated tires on my Tacoma, they are the Nitto Terra Grapplers. I immediately saw a 1-2mpg drop after putting them on, but managed to get it back by running them at 40psi front and 35psi rear. This is because the LT is heavier that the P in the same size, creating more rotational mass. It is most noticeable on initial acceleration. You might not notice any MPG or acceleration difference if you have the V8 engine, but my V6 can feel it. The 'D' load rating can safely run 65psi cold. The ride is definitely stiffer, but I actually prefer it that way. When running them at the recommended psi of 30 front and 26 rear, I couldn't tell a ride difference between the stock P rated tires I had on before. The LT does have a slightly deeper tread (1/16") so you should get better mileage if they are properly inflated and rotated. I have 10k on mine and they still look new, and have a 500 treadwear rating, as do the REvo tires, which should give you 50k easy. You can check out the different specs on the Revo here....

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Reply to
dave

I've been considering the same question. 265/75-16 tires have a slightly larger outside diameter than 265/70-16 tires, so you'd feel the loss of a small amount of power. Gas mileage might improve unless the higher "effective" gear ratio causes your transmission torque converter to unlock more often. 245/75-16 tires are about the same outside diameter as

265/70-16, but many folks don't like the skinny look.

I think I'll get P265/70-16 tires. That was Toyota's choice, and they likely know something I don't about tires for their trucks--although I disagree with them about inflation pressure, and we all know how they went cheap with the OEM Dunlops and Bridgestones.

For slippery road traction, I like to have my tires siped when they're about half worn. I buy new tires with good factory siping. When there's about

7/32'nds of an inch of tread remaining, I have the tire shop use their 5/32" sipe cutter. By then, the rubber is hardened from many miles of hot road surfaces & friction, the edges of the tread blocks are worn rounded, and often the factory siping is worn away.

Ken

Reply to
Ken Shelton

Thanks for input, Dave! I think you are right -- I will stick with the P-rated ones for now, considering my application.

Reply to
J.Smith

Yeah, I thought about that, too, but I think on a (mostly) unloaded V8 you would barely notice it, if at all.

You mean sooner-than-usual downshift? (What does "torque converter unlocking" mean?) I haven't even thought about that. You think on a 3% larger tire (which

265/75 is to 70) that would be significant? (How many MPG might I lose on average on a level road?)

I would go with 265/75-s. They are a little beefier and some $20 cheaper as well (larger but cheaper, go figure), but COSTCO (which is the cheapest source I was able to find) won't install them, 'cause they are over the OEM specs. So, I am scratching my head, should I buy them and install at another place thereby waiving the road hazard, or get the more-expensive (and less-desired) 265/70s?

That's interesting! Never heard of anyone doing that. How much such a service costs? I hope it's not too expensive.

Thanks, Ken!

Reply to
J.Smith

The torque converter on almost all newer vehicles locks the two halves at highway speeds to increase gas mileage. Its acts the same as a manual transmission when the clutch is fully engaged so there is no slip between them, the slip in an auto transmission being the fluid. You can accelerate with it locked, very gently on a flat road. Too much gas will make it unlock, which feels like a light downshift.

You should actually get slightly better mileage with the larger tire because the wheels are now turning less revolutions per mile at the same speed. If the tires are somewhat heavier than the stock tires, this usually balances it out. Remember to add 3% to your mileage when figuring MPG. 300 miles is actually 309.

265/75 are cheaper simply because they are a much more popular size. Many full size trucks and SUV's come with this size stock. If you have a Discount Tire store near you, go to them and tell them what quotes you have recieved from other stores. They will price match to get your business. The store I got mine at even installed them for $1 per wheel less their own wholesale direct price from the internet, after you figured in mounting and balancing, which is usually $1/inch. A 16" wheel tire is $16 to have mounted/balanced.
Reply to
dave

Thanks, Dave, for explaining the converter locking (and other stuff)!

mounted/balanced.

I certainly have a Discount Tire closeby (It's called America's Tire here) and they do price matching -- only problem, not on Bridgestones, which is a special order item. (Damn!)

Reply to
J.Smith

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