E vs F Rated nitto tires

[Travis1024]

Hey all - currently running 33x12.50r20 Toyo MT on my ‘16 1500 at about 40psi.
 

it’s almost time for new tires, and I’ve been wanting to switch over to the Ridge grapplers. I noticed they don’t make a 33x12.50r20 in a load range E tire (only F @ 80psi) In addition, I Also noticed most of the E range tires are rated for 80psi as well. I’ve heard running 80psi (or close to it) makes for a rough ride and my reason for switching from toyos is for a better ride, plus I think 80psi is overkill. 
 

1) can you run a much lower psi (40 or so) on 80psi rated tires? If so will it compromise ride quality and make them wear terribly? 
2) what’s the difference between an E and F tire both rated at 80psi?

[catpartsman]

The 80 psi rating is if you want the max weight rating of the tire. I’ve got E rated Toyos and I run 38 PSI in them. I’ve got right at 70K on them and still have roughly 1/2-5/8” of tread left. I’ve never ran them more than 40 psi either. Even wear all across tread too.


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[SSchup]

If you don't mind switching to a 305/55/20 which is almost the same size as the 33x12.50x20.

Nitto makes the Ridge Grappler in two ratings of that size. An F rated and the other is a 6 ply. I'm running 

the 6 ply at 40 psi and it is 10 Lbs. lighter then the F rated.

[Travis1024]

34 minutes ago, catpartsman said:

The 80 psi rating is if you want the max weight rating of the tire. I’ve got E rated Toyos and I run 38 PSI in them. I’ve got right at 70K on them and still have roughly 1/2-5/8” of tread left. I’ve never ran them more than 40 psi either. Even wear all across tread too.


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Not sure if this really matters, but the rating (On my e rated 33 toyos) is 65psi max vs 80psi on the e rated Nittos. So 40 on a 65 max tire vs 40 on an 80 max tire would be significantly different, right? That said, My knowledge on psi ratings vs what is best to run is very limited....

[Travis1024]

16 minutes ago, SSchup said:

If you don't mind switching to a 305/55/20 which is almost the same size as the 33x12.50x20.

Nitto makes the Ridge Grappler in two ratings of that size. An F rated and the other is a 6 ply. I'm running 

the 6 ply at 40 psi and it is 10 Lbs. lighter then the F rated.

That’s great to know. I Saw that one on their site and was curious because there was no ply rating. Assuming the attached is what you are talking about? How do they ride? Any pictures? I’d love to see that size as it sits on a truck. 

[catpartsman]

Not sure if this really matters, but the rating (On my e rated 33 toyos) is 65psi max vs 80psi on the e rated Nittos. So 40 on a 65 max tire vs 40 on an 80 max tire would be significantly different, right? That said, My knowledge on psi ratings vs what is best to run is very limited....

I doubt there’s really a difference between the two tires other than how much weight the tire can handle and the ride quality. The 80 psi tire I’m betting will handle more weight than the 60 psi tire. If your looking for mileage, run more psi since it will be easier rolling resistance. If you want better ride, lower the psi. If you want a happy medium, split the difference. As I mentioned, I have E rated tires on my truck and i run them at 38 psi. The ride is okay and mileage is okay. I have no need not desire to put more than 40 psi in my tires since I never haul anything of that weight in my half ton truck.


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[SSchup]

20 hours ago, Travis1024 said:

That’s great to know. I Saw that one on their site and was curious because there was no ply rating. Assuming the attached is what you are talking about? How do they ride? Any pictures? I’d love to see that size as it sits on a truck. 

They ride real nice and are actually pretty quiet for an aggressive looking tire. I lost about three mpg over the stock 275/55/20's original tires. I'm sure part of that was due to the 4 1/2" lift and the wider wheels also.

[Travis1024]

Than

4 hours ago, SSchup said:

They ride real nice and are actually pretty quiet for an aggressive looking tire. I lost about three mpg over the stock 275/55/20's original tires. I'm sure part of that was due to the 4 1/2" lift and the wider wheels also.

Thanks, that looks killer! I've got a 2.5" level and OEM GMC snowflakes on mine. My 33x12.50 rubbed a little when they were new. Wondering if I can fit these 305s without any rubbing. Wonder if the .06" loss in width will roughly negate the .23" in height as far as rubbing goes....

[SSchup]

Than
Thanks, that looks killer! I've got a 2.5" level and OEM GMC snowflakes on mine. My 33x12.50 rubbed a little when they were new. Wondering if I can fit these 305s without any rubbing. Wonder if the .06" loss in width will roughly negate the .23" in height as far as rubbing goes....

Hard to say. I have them mounted now on my stock LTZ wheels for the winter. I get a rub on my sway bar at full lock due to the positive offset .


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