Tire Load Ratings

Hi all. I installed a set of 265/75/16s on my stock SR5 wheels and it is an E rated tire. It says 80 psi on the tire, but the technicians at Discount Tire set them at 35. I added enough to get to 55psi because I didn't like having less than half the recommended pressure in there. At 35 it rode "ok" but at 55 it rode like shit. Do I really need E rated tires? If not, what are the other options? I'd prefer a softer ride even if it means the tire doesn't last as long. I'm trading the new set in on something more aggressive and really wanted the BFG AT KO2, but they only come in E. The only thing I tow is a utility trailer with my SxS.

 

You don't need an E rated tire but you also don't need to have it anywhere near 55psi. An E rated tire is for a 3/4 ton truck and the max PSI rating is for the maximum load rating. Those tires are rated to support 3415lbs each when inflated to 80psi. Your new E tires can provide the proper load handling for your truck at about 35psi.

 

Good to hear. I've been in an F350 for a few years and coming back down to a regular sized truck is taking some getting used to.

 

I run my E rated at 29psi. Rides great.

 

37 is the corrected pressure for that particular size and load rating.
55 is excessive.
https://www.tacomaworld.com/threads/air-pressure-in-10-ply-tires.666417/#post-23368540

 

What would be the difference in ride going from a Cooper E load tire to a Wrangler Goodyear DuraTrac with a C load range?

 

Requires the same pressure(37 psi).
Some claim a difference; some don't.

 

I have Toyo-at3 in E rated I run them at 34PSI. The greater available PSI rating can be used for carrying heavy loads.

 

Your truck rides on air, the tires simply contain that air. In the old days tires were rated by the number of plies. The more plies, the more air the tire could safely contain. They switched to load ratings because manufactures were able to get more capacity with fewer plies. A E load range is typically referred to as a 10 ply tire. Your truck new likely had 4 ply tires although that is even hard to guess because in p-metric sizes they now use a numeric load index. In any case going from a 4 to a 10ply tire is over kill. You by no means need that.

The amount of air is not dictated by the tire, it is the vehicle manufacturer. You should keep the air to at least what your placard shows as a minimum. You can increase up to the tires max. On passenger car tires this is usually 35psi. On C load range (or 6 ply tires) it is usually 50, and so on. Running a heavy load you want to run more air. Remember, you are riding on air and that is what gives you the load capacity. An E load range tire has a maximum of 80 psi. If you run it at 80, it will support the maximum weight per tire which is probably around 3200 lbs each meaning with 4 they will support 12,000lbs! Substantially more than what your truck is rated to carry plus the truck.

All of this means nothing because unless you up your axles, tranny, ect. you will never need that so why spend the money and have an awful ride? I would stick to Cs at most unless you plan on going off road. More plies will give you added resistance to punctures, but that is really the only advantage.

 

I run my LT265/75R16 10 Ply tires at 42 psi and the ride is fine to me.

 

Running 33" Toyo M/T which are E rated. I keep my fronts at 35 psi and the rears at 32 psi and it feels great. I air up the rears to 40 when loaded and all tires down to 15 psi when crawling or roosting the dunes and beach. I found C rated tires to be a bit soft and a bit squishy when cornering hard on pavement. E rated tires have a bit stiffer feel but I feel they handel better on and off road. But I also drive like I stole it and get sh!t gas milage so maybe don't listen to my opinion lol.

 

On E rated on these trucks you're looking 29-35 cold. Is tire dependant. The same pressure will not work for different makes of tires, gear truck weight etc. Chalk test is your best bet to get a better idea where you need to be. I check my pressures often. You will notice the sidewall flex on the C rated vs the E rated. They'll ride a little softer. I do not care for the wallowy feeling. Ymmv

 

Much better. Why did you buy E?

 

I believe certain sizes with certain manufacturers only come E rated. That is what it shows for the Duratrac's in 285/76R16 that I plan to get.

 

No, No, No. Absolutely wrong. Tires do not dictate pressure and the chalk test is an absolute joke. It provides zero useful information and is little more than a gimmick. I really don't understand why people still repeat this nonsense. I'm not bashing you. I'm guessing you probably heard about it on the internet like the majority of people that suggest it do.

 

Yes, this is correct and this is one of those sizes that the majority of them are E rated because this was an OE 3/4 ton Chevy size. They don't make many non Es in this size because while there is nothing wrong with putting a higher load range tire on any vehicle, you don't want to do the reverse. You put Cs on a 3/4 ton truck and you could find yourself in trouble if you load it down.

 

Sure dude. You do you

 

I'll bite:

What is a better alternative?

 

Quit dinking around.

Get a set of Michelin LTX AT/2. Begin with the pressure listed on the tag on the driver's side door jamb. Ride for a while, adjust pressure to your liking.

Suggest not to go below the door placard or over the tire's maximum pressure.

 

The best alternative is not putting too much thought into this. It is kind like the arguments over what is the best oil change frequency or a great octane debate. The key to air pressure is never going below the placard pressure (unless you are driving a 90s Explorer) and never going above the tires maximum. Anything between those numbers is a compromise. You want smoother, more comfortable Cadillac ride, go lower. The trade off is that your tires wont last along, and your mileage suffers. You want a stiff ride that you get better gas mileage, you go higher. The trade off is that your back will ache and your filling will fall out. The right answer is that as long as you stay in between those boundaries that you are ok. Just remember that all posted pressures are measured cold. Driving as little as a mile can increase your pressure.