SL/P vs LT rated tires discussion

[FDHog]

I just went through this. I went from factory P Hanook's to E General's ATx to SL Nitto's RG. The main reason, to get a lighter weight tire. The instant I drove away from Discount Tire on the Generals, the truck was notably slower to accelerate (3.31 gears), heavier steering/handling and rougher ride. I air up all my tires with 38 to 40 PSI. I tried several air pressures with the Generals, no dice. So back they went and I switched to an SL rated Nitto RG 305/55R20 116Q 2756 lbs. at 44 PSI. Night and day difference over the E tires. Acceleration was back, handling/turning was back, ride was back, love them. I typically tow a #5000 equipment trailer or a #4000 21' boat, and I haven't noticed any difference whatsoever, not even swaying

The way I look at is Ford didn't put E on my truck. I could be wrong but I think I read the non-HDPP rear axle is rated to #5000 ?‍ So why do I want a tire that exceeds the weight carrying capacity of the truck. One reason as mentioned above, sidewall strength. So when you do load up or have a heavy trailer, the truck doesn't sway back and forth as much. I did the sway test with my Generals and then my Nittos but I was hard pressed to see one tire sway more than the other. I suppose if you air up an E rated tire to 80 PSI it would be rock (Flintstone mobile) and not give at all

I also read "no no no, you need an E tire if you do any kind off roading, even a gravel driveway" There is a big write up in 4-Wheeler on the pros and cons of E rated tires for off roading that says otherwise...

Any way, just my $0.02 and hope it helps.

You ran 44psi in an SL rated tire and 38 to 40 in an E rated tire? Did you try 48-50 in the E rated General? I just switched to D rated KO2's and run 45-48psi. The truck handles better than with the P rated 20's. It doesn't feel mushy on the road anymore.
BTW, I ran E rated KO2's on my 2020 Raptor and it rode fine. It's all in finding the right pressure.

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[Je1279]

I recently stumbled upon the link below and it answered my PSI question for my new E rated tires. I'm currently running 38psi cold which gets to around 41psi warm. When I do any towing or hauling, I will adjust to 41psi cold which matches the load rating of the factory P rated tires at 35psi.

https://tiresize.com/pressure-calculator/

 

[Atlee]

I recently stumbled upon the link below and it answered my PSI question for my new E rated tires. I'm currently running 38psi cold which gets to around 41psi warm. When I do any towing or hauling, I will adjust to 41psi cold which matches the load rating of the factory P rated tires at 35psi.

https://tiresize.com/pressure-calculator/

Things sure have changed over the years. I had a 2014 steel bodied HDPP F150 that came with LRE tires. Ford recommended 55 psi in the front and 60 psi in the rear.

 

[Je1279]

My spine was not a fan of 45psi cold with the Bilstein suspension, although it was manageable. I imagine that 55/60psi would be even more unpleasant.

 

[Atlee]

My spine was not a fan of 45psi cold with the Bilstein suspension, although it was manageable. I imagine that 55/60psi would be even more unpleasant.

I never found it unpleasant. I'm probably not smart enough to know the difference. I'm ready to take the stock shocks on my PB and put heavier duty Bilstein's or the equivalent.

 

[bosro]

Ive run E rated tires in the past.
Mpg usually suffers(they are heavier)
And ride quality suffers....especially if running 20s.
I dont run them anymore....P rated or at best a D tire.
I do run aggressive treads(Last few sets have been Goodyear Wrangler Duratracs),do a fair bit of gravel and off road(especially in winter) and have never ripped a sidewall....or had any problems with a P tire besides picking up an occasional nail.
P rated tires tend to have less tread depth...and in some cases a bit different tread pattern(Duratracs dont)
If i rock crawled....maybe
Otherwise I wont
My next tire....Mickey Thompson Baja Boss AT
Standard 275/60/20 tire weighs 47lbs and has 16/32 tread depth(still pretty deep)
The LT 275/60/20 weighs 64lbs and has 18.5/32 tread depth.

 

[EricR]

Ive run E rated tires in the past.
Mpg usually suffers(they are heavier)
And ride quality suffers....especially if running 20s.
I dont run them anymore....P rated or at best a D tire.
I do run aggressive treads(Last few sets have been Goodyear Wrangler Duratracs),do a fair bit of gravel and off road(especially in winter) and have never ripped a sidewall....or had any problems with a P tire besides picking up an occasional nail.
P rated tires tend to have less tread depth...and in some cases a bit different tread pattern(Duratracs dont)
If i rock crawled....maybe
Otherwise I wont
My next tire....Mickey Thompson Baja Boss AT
Standard 275/60/20 tire weighs 47lbs and has 16/32 tread depth(still pretty deep)
The LT 275/60/20 weighs 64lbs and has 18.5/32 tread depth.

Please report back once you are running the Mickey Thompson's.

 

[HammaMan]

Keep in mind LT rated tires need ~30% higher pressure in them. The example of the HDPP truck pressures with LT being substantially higher is an example of this. Base trucks should be running at least 50 psi running such tires. To do otherwise impacts sidewall life.

 

[amschind]

I am really mystified about P/LT and the different load categories: It seems like one of them would be redundant for our purposes? Put another way, I get that LT is heavier, rides rougher, and is better for towing vs P's lighter weight and better ride, but how am I supposed to evaluate 6 ply vs 10 or 12 ply? We debate P vs LT all the time......and that's big difference. How are we going to form any kind of useful conclusion about something like E1 vs E2? I can see differentiating C vs E, but then again that seems like the P/LT distinction using different letters.

It is also comes up on the Discount Tire website, where they often list load category instead of P vs LT.

 

[FORDTEXAS]

I am really mystified about P/LT and the different load categories: It seems like one of them would be redundant for our purposes? Put another way, I get that LT is heavier, rides rougher, and is better for towing vs P's lighter weight and better ride, but how am I supposed to evaluate 6 ply vs 10 or 12 ply? We debate P vs LT all the time......and that's big difference. How are we going to form any kind of useful conclusion about something like E1 vs E2? I can see differentiating C vs E, but then again that seems like the P/LT distinction using different letters.

It is also comes up on the Discount Tire website, where they often list load category instead of P vs LT.

anything not C, D, E or F rated is considered “P rated”.

 

[Calson]

The difference is in the rigidity of the sidewall. It is the tire profile that affects the amount of sidewall on the tire. I hate low profile tires and had the beat displaced resulting in a flat tire after driving over 2x4s in the road on two occaions with my coupe. Unbelievable stupid for people to put low profile tires on a SUV or pickup truck.

The P tires on my 2022 truck provide a car like ride. The E tires on my last pickup made it ride like a truck which was not a problem as I have been driving pickups for more than 50 years and have expected this as part of the price of having a higher payload capacity.

 

[pavementends]

Keep in mind LT rated tires need ~30% higher pressure in them. The example of the HDPP truck pressures with LT being substantially higher is an example of this. Base trucks should be running at least 50 psi running such tires. To do otherwise impacts sidewall life.

Interesting, never heard this before. I've run LT LRE tires 40-50 psi for a decade. Can you point me in the direction of some manufacturer documentation for this? I'll Google too...

 

[Je1279]

Interesting, never heard this before. I've run LT LRE tires 40-50 psi for a decade. Can you point me in the direction of some manufacturer documentation for this? I'll Google too...

There are many differing opinions on this, but I know that Falken provides load ratings for their E rated tires down to 35psi. Personally, I run mine at 42psi cold.

https://www.falkentire.com/load-inflation

 

[GIjoe]

Hmm, I tried that calculator out and interestingly enough it calculated the same pressure that I settled on after driving and chalk testing

 

[pavementends]

There are many differing opinions on this, but I know that Falken provides load ratings for their E rated tires down to 35psi. Personally, I run mine at 42psi cold.

https://www.falkentire.com/load-inflation

Neat! 1,000 lb capacity difference (each) between 35 and 80 psi. Wow.

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