What's The Difference Between "p" Tires & "lt&q

seabee47 · December 7, 2010

My 2500HD came with Bridgestone LT265/70R17 Duravis M700 tires. I currently have about 32,000 miles and will be needing new tires in a month or so. I checked "Tirerack.com" and when I entered the 2010 Chev 2500HD 4WD, up came P265/70R17 tires. What is the difference between the "LT" tires and the "P" tires?

I'm leaning on replacing my tires with Michelins and will probably get them from Costco.

Diesail · December 7, 2010

The big difference comes to capacity. Since you are driving a HD I will assume that from time to time it has a load in it. Look at the load range of the "P" tires and if it high enough then there is no reason you can't use them. The last thing you want to do is overload a tire. Overload = more sidewall flex = more heat = boom. Think of a coat hanger when you bend it back and forth really fast until it breaks, does it got hot?

seabee47 · December 7, 2010

The big difference comes to capacity. Since you are driving a HD I will assume that from time to time it has a load in it. Look at the load range of the "P" tires and if it high enough then there is no reason you can't use them.

Both the "P" tires and the "LT" tires come in Load Range: E. Shouldn't a Load Range: E tire carry the same or similar load whether it is a "P" tire or a "LT" tire?

r1byker · December 7, 2010

This came from a tire site; it has a bunch of info that I didn't know:

"In the days when passenger car tires were used on passenger cars and truck tires were used on trucks, there was a clear division in the tires - basically by size, but there was also a difference in the way these types of tires (and their service) was analyzed to try to understand the theory behind what worked and what didn't. Remember, all this work would have been done prior to computers and all a guy had was a pencil and paper and his brain. Complicated analyses were just too time consuming.

So truck tires and passenger car tires developed along different lines and developed their own way to describing the relationship between inflation pressure and load - called the load curve and commonly expressed in the form of a load table. If you know anything about tires, you'll know that the larger the tire, the more load a tire can carry.

When smaller trucks were developed, vehicle manufacturers decided to use large passenger car tires, which have a softer ride. So new larger passenger car tire sizes were developed based on the previous formula, and this resulted in an overlap in the sizes. To distinguish between the 2 different types, the letters "P" and "LT" were put in front of the size.

But the interesting thing about the 2 different formulas was that P tires would carry more load than LT tires for a given size and pressure. Rather than rewrite the whole formula - after all these formulae had been successfully used for decades - they decided to limit the lower end of the LT sizing tables and the upper end of the passenger car sizing tables. Unfortunately it took over 10 years between the discovery of the problem and the limitations being agreed upon, and many tire sizes now exist in the overlap.

One way to look at this is that it isn't the size of the box that determines how heavy on object the box can hold - it's how much cardboard is used that matters.

With these 2 types of tires, the standard has been set and it is up to the tire manufacturers to develop a product that works for those conditions. As a result, these products are quite different internally and the constructions take advantage of the difference - the LT tires don't flex as much so they can be built stronger, while the P tires are built with flexibility in mind.

BTW, P tires are derated 10% when used in LT applications - Pickup trucks, Vans and SUV's. So what you see printed on the sidewall is not necessarily the actual load capacity."

Hope that helps.

Vortec-Z71 · December 7, 2010

Go with the LT tires. P tires are good for the 1500s but I would definitely go with the LTs for a HD.

searay220 · December 7, 2010

P tires are more for passenger cars or really light duty trucks and LT is for light trucks that are able to carry loads and handle more weight. A "P" rated tire is a 4 ply tire and "LT" tires are 6 ply=C,8 ply=D,and 10 ply= E. Go with what it says on the sticker on the drivers door jam.

jtramsey · December 8, 2010

Exactly go back with what it came with the LT.I tried A set of the P series On my 2500hd Rode better but not good for heavy hauling.

BlackSilver · December 8, 2010

Exactly go back with what it came with the LT.I tried A set of the P series On my 2500hd Rode better but not good for heavy hauling.

Use LT.

P rated tires have softer sidewalls and your handling when loaded will suck.

sonjaab · December 8, 2010

WARNING: Also note that your stock LT tires run at higher pressures than the same size P rated tires ! Like my stock 245s call for 50 frt and 80 rear while the same size P rated tires would run 35 lbs or so in all 4.

NOTE: So if you run a P rated tire with its lower pressures this will make the TPMS go nuts and produce SES and TPMS warning lights since the system is programmed for the LT tires and their higher pressures.

Good luck with having the dealer alter your TPMS settings for the P rated tires so your sorta stuck buying the more expensive (but well worth it if your truck is a heavy hauler workhorse) LT tires.

Lotta folks complain about those stock "donut/puny" 245 deathstones but IMO they wear like iron! I have had them on my last 3 2500s and never had to replace one because of a failure or issue.

They still look like new at 36k !

They are quiet and roll smooth down the road.

richardGMCwilson · December 11, 2010

i would run the LT tires on the HD trucks just if you do carry alot of weight all the time it will handle better, if you dont carry weight too often a P rated tire would ride nicer and dtill be tough enuff IMO

BlackSilver · December 11, 2010

i would run the LT tires on the HD trucks just if you do carry alot of weight all the time it will handle better, if you dont carry weight too often a P rated tire would ride nicer and dtill be tough enuff IMO

You gotta be joking! We aren't talking about half-ton grocery haulers. Softsided "P" tires would handle like crap on a HD, and arguably "unsafe at any speed". Stupid idea, REALLY stupid.

richardGMCwilson · December 12, 2010

i would run the LT tires on the HD trucks just if you do carry alot of weight all the time it will handle better, if you dont carry weight too often a P rated tire would ride nicer and dtill be tough enuff IMO

You gotta be joking! We aren't talking about half-ton grocery haulers. Softsided "P" tires would handle like crap on a HD, and arguably "unsafe at any speed". Stupid idea, REALLY stupid.

Yeah i just meant that i see alot of 3/4 and 1 tons used for grocery getting, it seems that some people are buying full size diesels for a status thing, like i had said, use lt if you pack weight or have a dually, if all you do is run around town buying groceries, and never having a single scratch in your box then i say run a p rated tire, i run LT's on my jeep comanche because i use it as a one ton, it carries a quad in the back, a boat on the rack,gas motor, two quads on the trailer and all of our gear, so yeah that classifies as weight, and use LT's for that, but if u use the truck for only groceries and once in a while put a little bit of weight in it, then i think a Prated tire is adequite, not recomended no, but adequite. thats all im sayin. i respect your opinion and agree with it even.

pistonslap · December 12, 2010

The big difference comes to capacity. Since you are driving a HD I will assume that from time to time it has a load in it. Look at the load range of the "P" tires and if it high enough then there is no reason you can't use them.

Both the "P" tires and the "LT" tires come in Load Range: E. Shouldn't a Load Range: E tire carry the same or similar load whether it is a "P" tire or a "LT" tire?

Are you sure? I don't think that P tires come in load range E. At least in Canada anyways. I say go for a load rating of E at least. I had load range C on a short box, reg cab 1500 and got tired of flats,so I switched to load range E. It handles better because of less sidewall flex,and the ride hasn't suffered in my case.