33x12.50 on stock 22s

[DavidNJ]

Interesting info. So please correct me if I’m wrong but the info provided states to find your oem load/inflation pressure and if you are installing a different size tire you would inflate it to a pressure closest to the corresponding load rating?

Based on the 114 load rating on the OEM Goodyear, I should inflate my 33x12.50s to...80psi?!?!? I had to have read the chart wrong lol. I’m currently running them at 50psi cold

If the original tire was metric, divide the capacity by 1.1 first. The LT tires have a 10% safety margin built-in. Then look up the pressure for that size that equal or higher capacity. Note that the difference between C, D, E, and F load ranges is the pressure. At a higher pressure the F has more capacity than the E, the E than the D, the D over the C.

Also note that the capacity closely maps to 1/2 the axle GAWR. If there is a much lighter load a lower pressure may be possible. Just remember to increase the pressure prior to fully loading it, trailer or payload. That last part wasn't in the manual.

BTW, what are you using for a spare. It looks like the 33x12.5 will in the spare holder, but it will drop down 1.5 inches more than 275., probably making it the lowest part of the chassis.

 

[DavidNJ]

Interesting info. So please correct me if I’m wrong but the info provided states to find your oem load/inflation pressure and if you are installing a different size tire you would inflate it to a pressure closest to the corresponding load rating?

Based on the 114 load rating on the OEM Goodyear, I should inflate my 33x12.50s to...80psi?!?!? I had to have read the chart wrong lol. I’m currently running them at 50psi cold

I think you may need to call AMP. The spec for a 33x12.5LT E is 2270 at 65psi or 2600 at 80psi. That is the spec for the Nitto Ridge Grappler. However, AMP shows there A/T A as 3195@80. That is the spec for a 35x12.5LT. It is what Nitto has for that size.

If the AMP spec is correct for their tire (what does the sidewall say?) then 43-45psi and you could run 35psi empty. If it is 2600lb@80psi then yes, you would need around 58psi-60psi.

The OE tire is rated at 2601@44psi and at spec 36psi is should be 2105 lb. That is the number you are matching.

What does your sidewall say?

This is there number: TOLL FREE LINE 866-894-3351

 

[ET32913]

Thanks for the info David, I’ll reach out to AMP and see what they say. I can’t imagine their load ratings being that far off from each other. That kinda drove me to arbitrarily choose 50 psi to run.

As for my spare, honestly haven’t thought about upgrading it yet lol but I should. I’ll have to look up the wheel specs and match the tire size up. For that steelie under there I may just look up the cheapest 33” tire as a temp.

 

[bobs4state]

I think you may need to call AMP. The spec for a 33x12.5LT E is 2270 at 65psi or 2600 at 80psi. That is the spec for the Nitto Ridge Grappler. However, AMP shows there A/T A as 3195@80. That is the spec for a 35x12.5LT. It is what Nitto has for that size.

If the AMP spec is correct for their tire (what does the sidewall say?) then 43-45psi and you could run 35psi empty. If it is 2600lb@80psi then yes, you would need around 58psi-60psi.

The OE tire is rated at 2601@44psi and at spec 36psi is should be 2105 lb. That is the number you are matching.

What does your sidewall say?

This is there number: TOLL FREE LINE 866-894-3351

The sidewall just gives a maximum of 80PSI. No way I am going to run that.

 

[DavidNJ]

The sidewall just gives a maximum of 80PSI. No way I am going to run that.

In this case the pressure rating on the manufacturer's website was different for the spec for that size tire. I suggested looking a the tire and calling the manufacturer to determine if their was an error.

Flotation tires—the ones with sizes of diameter x width such as 33x12.50LT—typically have lower load capacity than LT tires with metric ratings. They were designed for areas where having a low surface pressure (e.g. sandy beaches) is important. More likely to be aired down than towing a heavy load.

For some LT tires the equivalent to the OE Ram 113 can be a pretty reasonable pressure. For others, it could be significantly higher than the OE tire.

 

[DavidNJ]

The maximum pressure is only 1/2 of the equation. What was the load capacity at that pressure?

3195@80psi? That can be looked up in the LT tire table. Then scale the pressure to get your desired capacity. 2100 lb or 2300 lb be OE load capacity. If the sidewall reads 3195 lb@80 psi 48psi-50psi would be equal to OEM.

 

[Tipsterpfd]

Got these installed today, AMP Terrain Attack A/T A in 33/12.50 on stock 22-inch sport wheels. I was worried they’d rub but I have ZERO rubbing! My truck is leveled 2 inches with Readylift upper control arms. I should’ve mentioned this initially but I will say that clearance is pretty tight between the sidewall and UCA. I could barely fit a finger between the two but that gap is sufficient and will never change so its fine. I’m not sure if you’d have enough clearance with stock UCAs. View attachment 29613 View attachment 29614 View attachment 29615 View attachment 29616

Looking at same lift kit, how is ride with set up you have.