Nitto's finally on!

[TBontrager]

Regarding pressures, I'd be interested in hearing more of what people are running in their Nitto 305's. Big Bob quotes 45f/35r. I talked with a Nitto rep. and he gave me the following weight ratings at various pressures. I'd like to know how you would use this information to come up with optimum pressures for a loaded or unloaded truck.



PSI / Weight (lbs)

35 / 2290

45 / 2629

50 / 2910

60 / 3195

65 / 3525





Tim

 

[Seed Guy]

Here is a tidbit for ya. The nitto tera grappler and the toyo open country AT use the same carcass.

 

[GFoley]

For the 6. 5" wheel, all of the the tire mfgrs recommend ONLY 3 tires to fit that width. They are the 245/75, a 238/85, and a 255/85. EVERYTHING else recommends a minimum of 7" wheel width.



If ya find something else made by someone that say 6. 5 is OK, let me know. I decided to buy only wheels this time, not tires AND wheels so I went 255s. Maybe my next purchase will be both in a different size. BTW, a 255 on the 6. 5" doesn't extend beyond the fenders like anything wider will.

 

[nickleinonen]

Originally posted by Seed Guy

Here is a tidbit for ya. The nitto tera grappler and the toyo open country AT use the same carcass.

same company ownership too...

 

[Hohn]

Originally posted by TBontrager

..... I'd like to know how you would use this information to come up with optimum pressures for a loaded or unloaded truck.



PSI / Weight (lbs)

35 / 2290

45 / 2629

50 / 2910

60 / 3195

65 / 3525





Tim

Let me answer this question for you, Tim. Those pressures represent the load capacity of the tire at different pressures. This is usually the optimum inflation pressure (for tread wear longevity) as well.

You'll need to weigh your truck at a truck stop. This will give you the weight you have on your front and rear axles. Divide by two to get the weight on each tire.

For example, I weighed my truck and found that I had 2710# on the rear axle, 4100 on the front. That means I have 1305# on each rear tire and 2050 on each front tire. I would use this weight on each tire to lookup how much inflation pressure I need to support that load.

Do NOT just inflate your tires to max pressure (especially to the spec inside your door jamb). They will be overinflated for running around empty. That, and the spec on the door plate is ONLY for the stock 245 75R 16E size. Your owner's manual folder should have a tire inflation chart for the optional 265 size.

For 305s, you need to get the info from Nitto/Toyo as you have done, and inflate accordingly. Keep in mind that the 305s are E rated tires.

Also remember that for a given load, you need less pressure to support that load as you increase tire size. The stock 245s need every bit of 80 psi to support their max load, while the Nitto 305s can support MORE load at only 65psi. That's because pressure=force*area, so when you increase area (larger tires) you need less pressure to exert the same force.



I would say the 45f/35r pressures are pretty close to right on for an empty truck. When empty, you are nowhere near the tires load limit, and it takes a lot less pressure to support your truck's weight.



Remember, that if you have to err on one side or the other, it's better to overinflate (within the limit of the tire) than to underinflate. Too little pressure will cause the tires to run hot, break down, and may cause catastrophic failure in addition to uneven wear. Overinflation will cause unever wear only-- MUCH safer!



Happy inflating!





HOHN

 

[Hohn]

I forgot to mention that for your front tires, the weight on them is NOT the same. You will be fine if you just take the front axle weight and divide by two to average it, but the ACTUAL weight on the two fronts is different. Driver's side is a little heavier-- that's why most trucks have a heavier spring on that side of the axle (so it will sit level). My truck has 046 drivers side, 039 passenger side.



Or is it the other way around?