What psi should I be running 35"

I'm running 39 psi. My garage floor is so dusty I have a natural chalk test going on.

 

I run 50 for longer trips. 40-45 for around town and daily. 25 on the trails and air down to 15-18 for the trickier stuff. Last set of rubber on my FJ went just over 60k miles and still had plenty of tread left. Those were Procomp Extreme IIs, 35"

 

FWIW mpg is significantly better at the higher pressures. Downsides: traction is lessened, as are associated stopping distances. The ride will "bounce" more.

Just sayin

 

Maybe I’m an idiot… I run 25-30psi around town. Lots of highway miles at 80+mph. 35x12.5r18 Wildpeak at3w, load range F I believe. I love the cooshy feel and no problems so far. Got me thinking I should chalk line test tho…

 

40-42 depending on whatever the ambient air temp puts them at. Seem to be wearing nicely. 34” tires and 20” wheels. Load range E. Contemplated doing 50-60psi to see if the mileage changes any but been to lazy to actually try.

 

Seems like I’m in the 32# range with my 34” 275/65-20 LRE Cooper AT3 XLT tires.
I’ve ran these as high as 42# with no appreciable difference in handling or rolling resistance. I do bump them up when towing the RV.

Tread wear is even and I’m right at 55,000 miles on them now. I’m sure I could get 60-65K out of them, but I’m tired of waiting for my new ones to go on…

New Falken LRE 285/75-18 AT3W should be going on in the next few weeks, and expect them to run at a similar pressure.

 

I think your the first I’ve heard running the Wildpeak 35x12.5r18 since they’re only offered in load range F. Those are crazy heavy and just way over kill for a Tundra. I run an E load Wildpeak (295/70r18) and think its to heavy. Wish they made a c load 35x12.5r18!

 

I've run 50, 45, 40 and now decided to run 32 psi. Off road shop assured me it would be fine, but my problem was the stiffness since I have 35's on 20 inch rims (also E-rated sidewall). You'll be fine at 35 if you like the ride, just air them up to tow

 

To add my 2 sense about it I actually called toyo and spoke to the engineers there about this topic. Ik nerdy as hell, anyways the engineer gave me a formula to give a pretty good estimate on. It would have been smart to write it down somewhere but it should be pretty universal for our application. If I remember correctly it’s something along the lines of look at your OEM door placard with the OEM tire size and it gives you a psi rating for max load capacity and that load capacity manufacturers are kind of creating that with four people in the truck all seatbelted in with some weight in the bed to be on the safe side, so look up a normal load index chart for a passenger tire like a chart or a table take the psi that’s given and divide that by 1.1% And then you get your new load rating for floatation tires which are also known as LT light truck tires so you get your load index divided by 1.1 whatever your door says divided by 1.1 then you re-reference the load table and that should give you your psi so Talking to the engineer they're saying that with a full capacity of people in my truck, my front should be like I think they said 32,32 and 34 in the rear but she was like if you're just the one driving you have no one that rides with you that could go down so she was like realistically 34 is safe so you don't have to adjust your tire pressure but you know anywhere in that 30 to 34 psi range just for my application but it probably be the same for yours and the rating of the tire doesn’t matter if it's E or D8 ply or 10 ply does not matter the only thing that you're doing is passenger tires to floatation tires which are LT tires I may have butchered this but yeah lol the chalk test is also very good if you want to take the time to get the absolute best pressure

 

Look into the LRE vs LRF a bit more before assuming! It’s not as clear as it should be, for sure.

I’m willing to bet that your LRE 295/70-18 has a higher load capacity than the LRF 35/12.50-20 does. “Load range” is an antiquated system and doesn’t mean too much.

More accurate is the load rating index. A 3-digit number. Your 295/70-18 is probably a 127 or 129. I believe the 35” LRF is only a 125 or so.

That 35/12.5-20 is definitely heavier, but it’s a much larger tire.

Our LRE tires are likely just as much overkill as that LRF.


Just looked it up on Falken’s site…

35x12.50-20 LRF:
34.6” x 12.7#
Load index 125
Weight is 76#
Capacity is 3,640#


295/70-18 LRE:
34.3” x 11.9#
Load index 129
Weight is 68.1#
Capacity is 4,080#

 

100% agree. Overkill... and intentional. I frequently go places I shouldn't go alone (hunting) and the peace of mind is worth a reduction in ride quality. I saw an Australian video that showed a small increase in puncture resistance with higher load range tires (video didn't test sidewall, which I would expect to be no different). Also, I have 5.29 gears so tire weight is not felt when accelerating. Haven't noticed a difference when braking.

Falkin actually makes a 35x11.5R18 (load range C) that is considerably lighter (62.6# vs 73.9# for the 35x12.5R18s).

Also: Chad D - you are correct. Falkins AT3W size 295/70R18 (load range E) have a load rating of 4080# whereas their 35x12.5R18 (load range F) are rated to 3970#.