Silverado 1500 tire pressure when towing

[malibu43]

Thanks for all the perspective folks. I'm leaning toward running 65PSI for this upcoming trip to see how it goes. We have another long trip in the later part of July and I can adjust as needed before that trip.

For regular driving and our shorter camping trips (< 1hr drive time), I'll run them back down around 36-40.

[sourdough]

Originally Posted by malibu43

Thanks for all the perspective folks. I'm leaning toward running 65PSI for this upcoming trip to see how it goes. We have another long trip in the later part of July and I can adjust as needed before that trip.

For regular driving and our shorter camping trips (< 1hr drive time), I'll run them back down around 36-40.

Here's a link to an inflation chart that has your tire size on it. It's from Falken tires but should be accurate for yours. If you have scaled weights you can get very close. If you don't you want to err on the side of safety. Being a bit high on pressure does not hurt anything appreciably where as being low can be dangerous. Just drove through a wet swath on my drive with my empty truck aired to 80psi - same track print as when they are at 65 psi - no skinny tire patch.

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

[malibu43]

Originally Posted by sourdough

Here's a link to an inflation chart that has your tire size on it. It's from Falken tires but should be accurate for yours. If you have scaled weights you can get very close. If you don't you want to err on the side of safety. Being a bit high on pressure does not hurt anything appreciably where as being low can be dangerous. Just drove through a wet swath on my drive with my empty truck aired to 80psi - same track print as when they are at 65 psi - no skinny tire patch.

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

Thanks. That's very helpful.

[fjr vfr]

I think running 36psi would be a little low for E rated tires. 40psi might be okay. Personally I'd run 50psi on that truck empty. Remember it's the air pressure that supports the weight so you you don't want to transfer that chore to the side walls of the tire. Those tires on that truck will always give you a stiffer ride no mater what pressure.
You might try 40psi front and 50psi rear, but I wouldn't go below 40psi.

[CWtheMan]

“P” tires are load index tires and their inflation charts are different from “LT” tires which are Load Range tires.

Your OE tires should have had a load index of 114. That load index will provide a maximum load capacity of 2601# of load capacity at 35 PSI.

When looking at a load inflation chart for the “LT” tires, a PSI value of 55 PSI will provide the necessary load capacity from them to satisfy tire industry safety standards.

[jadatis]

Found the 275/60R20 123 loadindex in the falken list given here.
Has 3417 lbs maxload AT 80 PSI.
So used that to make the list.
In front of cold psi axleload to look back, and behind heavyest axle-end load to look back.
Both for singleload axle, assumed you only have that. All with max reserve at wich still acceptable comfort and gripp. And you are responcible for the given loads to be accurate.

Axleload / cold psi / heavyest axle-end

1749 lbs/ 20 psi / 923 lbs
1901 lbs/ 22 psi / 1003 lbs/ EUR lowest
2053 lbs/ 24 psi / 1084 lbs
2205 lbs/ 26 psi / 1163 lbs/ US lowest
2356 lbs/ 28 psi / 1243 lbs
2506 lbs/ 30 psi / 1322 lbs
2656 lbs/ 32 psi / 1401 lbs
2805 lbs/ 34 psi / 1480 lbs
2954 lbs/ 36 psi / 1559 lbs
3102 lbs/ 38 psi / 1637 lbs
3250 lbs/ 40 psi / 1715 lbs
3398 lbs/ 42 psi / 1793 lbs
3545 lbs/ 44 psi / 1871 lbs
3692 lbs/ 46 psi / 1948 lbs
3839 lbs/ 48 psi / 2026 lbs
3985 lbs/ 50 psi / 2103 lbs
4131 lbs/ 52 psi / 2180 lbs
4277 lbs/ 54 psi / 2257 lbs
4422 lbs/ 56 psi / 2334 lbs
4567 lbs/ 58 psi / 2410 lbs
4712 lbs/ 60 psi / 2487 lbs
4857 lbs/ 62 psi / 2563 lbs
5002 lbs/ 64 psi / 2640 lbs
5146 lbs/ 66 psi / 2716 lbs
5290 lbs/ 68 psi / 2792 lbs
5434 lbs/ 70 psi / 2868 lbs
5577 lbs/ 72 psi / 2943 lbs
5721 lbs/ 74 psi / 3019 lbs
5864 lbs/ 76 psi / 3095 lbs
6007 lbs/ 78 psi / 3170 lbs
6150 lbs/ 80 psi / 3246 lbs/ maxloadpressure
6293 lbs/ 82 psi / 3321 lbs
6435 lbs/ 84 psi / 3396 lbs
6578 lbs/ 86 psi / 3471 lbs
6720 lbs/ 88 psi / 3546 lbs
6862 lbs/ 90 psi / 3621 lbs/ sometimes also given maxcold pressure

[JRTJH]

I don't know how to diplomatically say this, so I'll just post what I'm thinking.

The "hand calculated chart" in the previous post is simply not correct, or else Falken Tire Company's chart is incorrect and they haven't taken the time to correct their errors. Below is the Falken Tire Company data for the specific PSI required to carry the rated tire load. Note that 65 PSI is the standard inflation pressure for LRD (8 ply rating) tires and 80 PSI is the "standard inflation pressure for LRE (10 ply rating) tires.

Looking at the corresponding air pressure/load capacity from the Falken Tire chart and this "hand calculated chart" there is anywhere from 300 to 425 pounds difference in capacity. That's almost half a ton difference when you consider there are 4 tires on most trailers, each carrying 25% of the rated load.

I'd be inclined to discount the above chart as incorrect and follow the Falken Tire Company information which is the same as the NITTO Tire Company chart and the TOYO Tire Company chart, so very likely to be "the correct information as it relates to the standards established by the USDOT guidelines.

The TOYO Tire Company inflation chart is identical to the Falken chart, so I'd say that confirms the standard used in the US. https://www.toyotires.com/media/pxcj...s_20200723.pdf (See the last entry on Page 28)

LT275/60R20 Single:
PSI/LOAD
35/1920
40/2110
45/2290
50/2470
55/2635
60/2800
65/3000 (D) 123
70/3120
75/3275
80/3415 (E) 123

The photos below are from information sources that are valid for tires sold in the US. Since all of them are from different tire manufacturer websites, and since they all have the same information, presented in the same manner, I'd be inclined to believe the US sources over any "hand calculated information posted by someone who is not a US authority on USDOT data"... YMMV

[jadatis]

Difference between my list and the officiall lists, is that I include a reserve by giving 90% of the calculated loadcapacity for the pressure for the axleload, and 95% for heavyest axle-end load.
Then I calculate with even safer formula then the european official for all kind of tires, and since 2006 for P tires in US, wich on its turn is safer then LT calculation in US.


All so you dont need to do pre-calculations.

My list leads to higher pressure, so never bad for the tires.

So if with my list determined pressure gives still acceptable comfort and gripp, why not.
I dont go for minimum, but maximum, at wich gripp and comfort is still acceptable.

[CWtheMan]

All tire load inflation charts used in the USA are standardized by the Tire and Rim Association.

[rhagfo]

Originally Posted by JRTJH

I don't know how to diplomatically say this, so I'll just post what I'm thinking.

The "hand calculated chart" in the previous post is simply not correct, or else Falken Tire Company's chart is incorrect and they haven't taken the time to correct their errors. Below is the Falken Tire Company data for the specific PSI required to carry the rated tire load. Note that 65 PSI is the standard inflation pressure for LRD (8 ply rating) tires and 80 PSI is the "standard inflation pressure for LRE (10 ply rating) tires.

Looking at the corresponding air pressure/load capacity from the Falken Tire chart and this "hand calculated chart" there is anywhere from 300 to 425 pounds difference in capacity. That's almost half a ton difference when you consider there are 4 tires on most trailers, each carrying 25% of the rated load.

I'd be inclined to discount the above chart as incorrect and follow the Falken Tire Company information which is the same as the NITTO Tire Company chart and the TOYO Tire Company chart, so very likely to be "the correct information as it relates to the standards established by the USDOT guidelines.

The TOYO Tire Company inflation chart is identical to the Falken chart, so I'd say that confirms the standard used in the US. https://www.toyotires.com/media/pxcj...s_20200723.pdf (See the last entry on Page 28)

LT275/60R20 Single:
PSI/LOAD
35/1920
40/2110
45/2290
50/2470
55/2635
60/2800
65/3000 (D) 123
70/3120
75/3275
80/3415 (E) 123

The photos below are from information sources that are valid for tires sold in the US. Since all of them are from different tire manufacturer websites, and since they all have the same information, presented in the same manner, I'd be inclined to believe the US sources over any "hand calculated information posted by someone who is not a US authority on USDOT data"... YMMV

Well we are talking the tires on the 2021 GM 1500 with a 7,100# GVWR, OP never stated the rear axle rating, but most are 3,900# with the unicorn F150 at 4,800# so based on the chart you provided. The OP should inflate the the tires to 45 to 50 psi more than enough on a 1/2 ton rear axle.

[jadatis]

Answer to post #30 above.

GAWR/ official list/ official with first 10% added/ my list/ you give

3900lbs/ 40psi/ 45 psi/ 48 psi/ 45psi.
4800lbs/ 50psi/ 55 to 60 psi/ 62psi/ 50psi.

So whoever is right, 80 psi is way to high if GAWR's not overloaded to much. Makes the TV ride like an old army truck.

Hoped, with my posts, to keep this topic below 40 posts.
Wayting on Malibu's weighing efforts, know it can take a while.

Oh, Malibu, check sidewall of tires if the found specifications in Falken list are right

[JRTJH]

Well, turns out there's a "internet webpage for that"
https://tirecalculator.com/tire-pressure-calculator

Here's what that webpage recommends for "daily driving" using the load capacity of the OEM tire @36PSI and conversion to the closest load capacity for LT tires of the same size. So, I'd suggest following this chart for "daily driving" with the understanding that LT tires "ride rougher" than P-metric tires due to stiffer sidewalls) and increase the pressure when towing, not for the purpose of increasing load capacity but rather to increase sidewall stiffness to prevent sway induced by flexing sidewalls.

How much to increase pressure for towing? That depends on the rig since trailer size and loading, hitch adjustment, crosswind strength, and many other factors play on stability. Sidewall flexion is just "one of many" to consider.

Here's the "tire calculator pressure chart recommendation" of 50 PSI:

[mjsibe]

My 2016 Chevy Express 3500 6.0
Has 245 / 75 /16 Lt.
Stock tire. 60 psi Front 80 psi Rear.
Now usually run 10 psi lower for daily running.
Air up to max when towing or carrying heavy loads.
Attached is a Sample tire pressure chart.
Find your manufacturers chart.
Various psi for known loads.
Hope this helps.

[rhagfo]

Originally Posted by mjsibe

My 2016 Chevy Express 3500 6.0
Has 245 / 75 /16 Lt.
Stock tire. 60 psi Front 80 psi Rear.
Now usually run 10 psi lower for daily running.
Air up to max when towing or carrying heavy loads.
Attached is a Sample tire pressure chart.
Find your manufacturers chart.
Various psi for known loads.
Hope this helps.

Not really the OP put E rated LT tires on a GM 1500, the only way he would need 80 psi is if he extremely overloaded his rear axle.

[pawpaw]

I've been running 65 to 70 psi cold when towing our 8K pound camper. 10 ply BFG KO2's on a FX4 Expedition. I'll put 70 psi in the rears to cut down on some sidesway due to independent rear suspension. Also our Cougar is a heavy little sucker on the hitch weight. Tows OK but don't take it on long trips. Daily driving I run 45 to 47 psi and truck handles great at that pressure for daily driving and long trips.

[rhagfo]

Originally Posted by pawpaw

I've been running 65 to 70 psi cold when towing our 8K pound camper. 10 ply BFG KO2's on a FX4 Expedition. I'll put 70 psi in the rears to cut down on some sidesway due to independent rear suspension. Also our Cougar is a heavy little sucker on the hitch weight. Tows OK but don't take it on long trips. Daily driving I run 45 to 47 psi and truck handles great at that pressure for daily driving and long trips.

Boy I thought I was as Old as dirt, I haven't referred to tire rating by number or ply rating in a while. LT tires nowadays have load range numbers and letters. I went out and looked at the 235/85-16E tires on our 3500, two side wall plys and six plys in the tread area, yet rated for 3,085# ea.
In looking at the tire there more words and warnings molded into the tire than I care to read.

[JRTJH]

Originally Posted by rhagfo

...
In looking at the tire there more words and warnings molded into the tire than I care to read.

Yep, a "unfortunate evolution from common sense to protect the consumer"...

Take a look at any 99 cent white 6' extension cord. There's 3 bucks worth of warning labels wrapped around that dollar's worth of wire.....