My 1500 series Sierra came with P265-65-R18 from the factory. The tires have been OK, but I've always found that when loaded (even with the WDH) the steering is a bit loose. In speaking with others with the same style truck, they've upgraded rims and tires switching their P series stock tires to LT tires. I'm told the stiffer side wall makes a big difference in the handling.I'd like to perform the same upgrade, however I already have stock rims that I like. Can I install LT265-65R-18 tires on my stock aluminum rims? The recommended tire inflation on my P series tires is 35 psi. The LT has a recommended inflation of 50 psi. I understand my TPMS in the truck alarms at 29 psi so I'll either need to calibrate it or check inflation on a regular basis on my own.Is there anyone out there that has upgraded their tires in the same manner? Has it lead to any issues?Thanks in advanced for any posts.

I think you'll be very satisfied with that change.

Shouldn't be any problem. I'd recommend replacing your valve stems with higher rated ones, though. The lower ones tend to leak more air over time than the higher ones. Etrailer.com has them, just get the length and diameter you need. Call and tell them what you have and they will help you select. Hint: the smaller diameter fits passenger vehicles (non-commercial)You are likely to be floored at the improvement under load with the stiffer tires. I now have 10ply on my 4Runner (60 psi empty, 70 psi towing) and it is rock solid, even near the max tow rating and 60-70mph.

Back when we towed with an Expedition we changed the P tires to LT's. Great improvement.

Money well spent on LT's -- you change your reader gauges to higher rated, not a big deal.

Do you tow with your tires at 35 PSI? If so, try towing with them inflated to the most likely 44 PSI to achieve the max load rating.

Replacing P series with LT on a 1500 Sierra | Good Sam Community

ScottG
Nomad
Jul 31, 2014
I think you'll be very satisfied with that change.
DiskDoctr
Explorer
Jul 31, 2014
Shouldn't be any problem. I'd recommend replacing your valve stems with higher rated ones, though. The lower ones tend to leak more air over time than the higher ones.

Etrailer.com has them, just get the length and diameter you need. Call and tell them what you have and they will help you select. Hint: the smaller diameter fits passenger vehicles (non-commercial)

You are likely to be floored at the improvement under load with the stiffer tires. I now have 10ply on my 4Runner (60 psi empty, 70 psi towing) and it is rock solid, even near the max tow rating and 60-70mph.
downtheroad
Explorer
Jul 31, 2014
Back when we towed with an Expedition we changed the P tires to LT's. Great improvement.
monkey44
Nomad II
Jul 31, 2014
Money well spent on LT's -- you change your reader gauges to higher rated, not a big deal.
ktosv
Explorer
Jul 31, 2014
Do you tow with your tires at 35 PSI? If so, try towing with them inflated to the most likely 44 PSI to achieve the max load rating.
Campfire_Time
Explorer
Jul 31, 2014
LTs are a good choice and its possible that you can install them on your stock wheels depending on their PSI limitations.

However an alternative is to buy P rated tires that are made for trucks and SUVs. My truck was used when I bought it and has P rated SUV/truck tires that can take 51 PSI. I've been towing at 45 psi and there is a world of difference between that and the factory recommended 35 psi. I've been pretty happy with them, a lot more than I thought I was going to be. I thought I'd be contemplating the same thing as you are.

As far as the TPMS goes, mine doesn't have an alarm (that I've been able to find). So long as the system know which wheel is where I can put what ever amount of air I want. I just have to manually check the menus for current PSI.
popeyemth
Explorer
Jul 31, 2014
Went to Michilean LTs on our 2007 Silverado 1500. .
Got them on sale at SAMs Club and they added the high pressure stems to our stock alloy rims for free.
We switch between a truck camper and trailer and big loads of rock and love the improvement .
Good Luck, Mike
Need-A-Vacation
Explorer
Jul 31, 2014
I put 275/65/18 LR C Cooper A/T3's on our '10-1500 Chevy and was very happy with them. No longer had what I call a "wiggle" in the rear when towing the tt. No issues with the tpms either!!!
The_Texan
Explorer
Jul 31, 2014
Our 2011 1500 came with 20" optional rims and P rated tires. I switched to Hankook LT tires an love them. When you have the sensors reset by the tire dealer, they will automatically go to the new low pressure setting for the tire.
Tystevens
Explorer
Aug 04, 2014
It sounds like I'm in the minority. But I've switched to LTs twice on 1/2 ton vehicles and not seen a huge improvement.

Disclaimer -- I towed lots of miles on P's with my '05 Suburban, switched to LTs and only towed a few times before buying my 2500 pickup. And with my F150, I only towed on the stock P's a couple times before putting the current LT's on (Michelin LTX M/s2), as the stock Goodyears were pretty worn when I bought the truck this spring.

But I towed at 44 psi or so on my P's, and about 55 psi with the LTs. I can't say I see a big difference. The mpgs on my F150 have dropped off by 5-10% since switching to LTs, however, since they are a bit heavier.