Pathfinder I
Yup. I install them then walk around checking other things on the truck, checking out other people's trucks or taking photos. They always get my pressure to within 1 or 2 psi of where I want it and that's good enough offroad.
What tire pressure are you running your e rated tires at for daily driving?
- Thread starter Tray
- Start date
Here you are a tire size calculator:
tiresize.com
But in fact I did not find a certain tire size listed in the link above when I searched for it; it is the tire of the Land cruiser 71 (short wheelbase) and it is a 16" with the following values:
225/95R16 = 32.83X8.6R16
Which can be converted as follows:
Diameter = 2((.95)(225))+((16)(2.54)(10)) mm
Diameter = 2(213.75) + 406.4 mm
Diameter = 427.5 + 406.4 mm
Diameter = 833.9 mm
Diameter = 32.83 "
The most nearest one listed in the site above was the following one:
32X9R16
while mine is:
32.831X8.6R16 ~= 32.8X8.6R16
May be some other sites have better calculators of Tires sizes.
Tire Size Calculator
The best tire size calculator. Use our tire size calculator to find tire size specs and suggested tire sizes. Then check prices for all available tire sizes.
But in fact I did not find a certain tire size listed in the link above when I searched for it; it is the tire of the Land cruiser 71 (short wheelbase) and it is a 16" with the following values:
225/95R16 = 32.83X8.6R16
Which can be converted as follows:
Diameter = 2((.95)(225))+((16)(2.54)(10)) mm
Diameter = 2(213.75) + 406.4 mm
Diameter = 427.5 + 406.4 mm
Diameter = 833.9 mm
Diameter = 32.83 "
The most nearest one listed in the site above was the following one:
32X9R16
while mine is:
32.831X8.6R16 ~= 32.8X8.6R16
May be some other sites have better calculators of Tires sizes.
Last edited:
Advocate II
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Tire pressure debates cracks me up.. I’ve been running with 36lbs in 285/75/16s BFG KO2s. Underneath a 6,000 lb Landcruiser 80 series.. I run 22lbs in our trailer that’s scales out at 1,000lbs .. on a long trip and loaded down I’ll put 38 lbs in the rears.. I get flat even wear and easily attain 50,000 miles and more,, don’t know how much more cause I sell them used at 50k and get new ones.. Tire pressure is dependant on one thing, the weight on the axle.. 18 wheelers have 12,000 lbs on the steer axle and run 90 lbs.. 100-120 lbs on the drives and trailers @ 16,000 each .... you guys that are running 60-70 and 80 lbs— Why? You simply don’t have enough weight to justify that much air pressure.. I’m completely unfamiliar with your logic and a lot of guys do this .. thanks & peace out
Close. Pounds of pressure multiplied by the surface area = amount of force. That surface area is mostly your contact patch, but some types of tire construction allow the rest of the tire to help a bit.
A larger diameter 37 x 13.5" wide tire, has a larger contact patch, so it can lift more weight at a given pressure than a 245/75. Semi truck tires are quite large. Construction makes more of a difference as well. F rated or heavier tires are rock hard at 90 psi.
I can say with complete certainty, that a Goodyear, E rated 245/75r17, Duratrac, can't lift the max weight it's rated for, at 88psi. It'll be on it's side walls. Lol.
But a Cooper STT or Firestone Transcrete AT2 will be pretty solid at 88.
My F250 CC Fx4 sits on Michelin LTX AT's with less than 1000# cargo, 55psi front, 45 psi rear. Add a slide in camper or a large TT, and I go straight to 70/88.
A larger diameter 37 x 13.5" wide tire, has a larger contact patch, so it can lift more weight at a given pressure than a 245/75. Semi truck tires are quite large. Construction makes more of a difference as well. F rated or heavier tires are rock hard at 90 psi.
I can say with complete certainty, that a Goodyear, E rated 245/75r17, Duratrac, can't lift the max weight it's rated for, at 88psi. It'll be on it's side walls. Lol.
But a Cooper STT or Firestone Transcrete AT2 will be pretty solid at 88.
My F250 CC Fx4 sits on Michelin LTX AT's with less than 1000# cargo, 55psi front, 45 psi rear. Add a slide in camper or a large TT, and I go straight to 70/88.
Expedition Master III
I have to say that forums like this, and watching You-Tube videos, have given me better knowledge, and a broader understanding of proper inflation choices. In years past, it was lower PSI in sand, but never to the extent now accepted as adequate, due to not having a way to pump them up outside of a service station, That problem was finally rectified. Secondary was the on road PSI was dictated by front axle weight (Diesel Engine). I kept the rear tires at a lower pressure due to riding empty in-town most the time. In my 3/4 ton it minimized the Pogo stick affect. I also tried to reduce outside front scrub, by ensuring a slightly higher pressure, which I evaluated frequently to avoid CROWNING down the center of the tread. I never had a issue with any excessive wearing, due to rotations being done. All my sets had fairly even wear at the end of their useful tread depth.
But I now have the tools to customize my air pressures to match my environment. This means lower pressures on unimproved fire roads, back country access trails etc. In the last 4 years I have added a Vivair 88P compressor, a deflater kit, a Digital PSI gauge, and a better tire patch-kit setup. My E-rated tires, 285x75x16 AT's, run about 65 PSI front, 50 PSI rear. in town. The worst thing is running under inflated in the Desert summer months, as inherent heat buildup + excessive road surface temps= NOT GOOD. Remember; these are E-Rated LT tires, not P-Metric, or even C rated LT's. They can take a higher PSI. I just intend to moderate my past acceptable pressure, and find a better, more compatible lower one. Your never too old to learn
But I now have the tools to customize my air pressures to match my environment. This means lower pressures on unimproved fire roads, back country access trails etc. In the last 4 years I have added a Vivair 88P compressor, a deflater kit, a Digital PSI gauge, and a better tire patch-kit setup. My E-rated tires, 285x75x16 AT's, run about 65 PSI front, 50 PSI rear. in town. The worst thing is running under inflated in the Desert summer months, as inherent heat buildup + excessive road surface temps= NOT GOOD. Remember; these are E-Rated LT tires, not P-Metric, or even C rated LT's. They can take a higher PSI. I just intend to moderate my past acceptable pressure, and find a better, more compatible lower one. Your never too old to learn
It's hard to say exactly. It depends on the weight of your rig mostly. My thought is that you should run them for awhile and check tread depth and tire wear. If you notice more tread wear in the center vs the edges, you'll know whether to increase or decrease tire pressure.
Enthusiast II
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