Largest tire size that is OK for towing without having to regear?

Finally Installed my 2.5" ARB OME suspension lift this weekend. I wont to put bigger tires on. I just bought a Camper 7500 lbs gross 600 lbs hitch weight. What are the tallest Tires that I can safely put on without needing to regear?

 

i think it depends more on the weight that you're adding to the truck. if you go with lighter wheels, you could put 35s on and not affect your towing capabilities. i went from the stock 20" wheels and tires to 18" wheels with 295/70 and shaved 1.5lbs at each corner.

 

I guess I should have mentioned the wheel size I have the 18" 2021 Pro wheels, they are the BBS Forged and pretty light weight. How much weight do you Tow with the 295/70 and do you have any rubbing issues?

 

I'd say the sweet spot would be 295/70/18. I have a slide in camper and sometimes tow a trailer. Considered going up to the true 35" tire but I think it would require a regear for proper function on the highway.

 

I have 295/70/18 and am considering re-gearing for a much lighter trailer (<3000lbs, but very tall, so the vacuum caused by the trailer is big), and I don't feel like running my truck at 3000 rpm for 16 hours straight.

 

The answer to your question is really subjective. You're going to get a ton of opinions but the real answer will be "it depends".

Some things to consider:

1. What is the elevation? A naturally aspirated engine loses about 3% of its power for every 1000 feet of elevation gain. So the experience of someone who lives in Colorado may be less relevant to someone in Florida.
2. What type of tread? A mud terrain is different than an AT. Bigger lugs generally increases resistance.
3. How heavy is the tire? If you decide to go up from OEM on load rating you're likely increasing the weight of the tires. Heavy wheels and tires directly impacts performance.
4. What speed do you cruise at? If you want to go 75 MPH everywhere with a 7k trailer you may not want to go larger.
5. Toyota V8's are designed to rev to be in the power band. But are you? Some people just hate the idea of running in 4th gear all day and consider it a truck fail when the rpm's go up. Bigger the tire, the more rpm's you are likely to see while towing.

For me, with living at about 4000 feet and regularly traveling over mountain passes while towing my "aerodynamics of a brick" travel trailer, I would not be happy with the performance of towing with >34" tires and OEM gears. But again, that subjective for me.

 

What a difficult question.

1 weight: weight sucks and you feel it in tye seat of your pants.

2 drive ratio: i went from stock 20s with a 32 to a 275/70/18 and my final drive ratio is about 4.10 instead of the factory 4.30.

I have Wildpeaks and despite going lighter wheels, I still added about 10lbs per corner. Couple this with the reduced final drive ratio and I've dabbled with the idea of regearing for a 33" because it just doesnt have the power in the right ranges like it used to when towing. A lighter tire choice would help, but tire selection is a different topic I wont get into here, aside from understanding tradeoffs of each, to include weight.

 

Smaller diameter tires allow the drivetrain to work easier, no question about it. Like said above, many factors, so no one size fits all here.

 

Very subjective. But, I tow a 5k lbs total weight trailer, have 35” tires with added truck weight, stock gears and live at about 5,000 feet with trips often going to around 7,000 feet. I do notice the trailer on steep grades but otherwise it is fine IMO.

 

Mountainpete, Thanks for the info you gave me a-lot to think about and consider. You seem way more knowledgeable on this subject than I am. Could you throw out a recommendation with some of my information please?
1. I also live at about 4000 feet and occasionally travel over mountain passes.
2. All Terrain Tread
3. The wheels are the BBS Forged from a 2021 TRD Pro and are pretty light. Tires TBD
4. Speed 65 when Towing.
5. 4 Gear does not bother me when Towing.

 

Look at 285/65 r18. Depending on the manufacturer it's basically a 33" x 11.5. Slightly taller and wider to give a more aggressive stance for all of those times you aren't towing, but not much taller overall. From a size perspective, this is probably the safest bet. Weight of course depends on the manufacturer.

I would also look at 275/70 r18. @bflooks above shared some great info. It's a taller tire but the same width as OEM.

Overall, your Tundra is super capable even with larger tires. Think honestly about how much you really tow. Is it only really a few times a year? If so, a bigger tire may be worth the trade off for other benefits. But a bigger tire will also mean less fuel mileage throughout the year and higher replacement costs.

And for reference, this is my Tundra, with 285/65 r18. Elka suspension around (about 2.5" lift front), Icon add a leaf rear, coachbuilder shackle +1 and airbags (with 15 psi as I just unhitched the trailer).

 

I went OCD on research and went with 295/70/17s; they have proved to be a good balance however anytime you drop revs/mile re-gearing will optimize performance WRT shift points and HP. A friend told me.... she still hauls ass-in BEAST mode.