Do you keep your tires at full capacity? 80psi

[FirstAscent]

Tire PSI will always be a debate/question as to what is best. I have my methods I stick to which is based off of Load and Inflation tables. I first learned about this about 7 or 8 years ago and have followed it since and will continue to do so. 

 

If you look at the door tag on your vehicle, that's how the recommended PSI is calculated from the factory as well depending on the weight of the vehicle and exact tire size. One thing to be aware of is that the same size tire of one brand will have the same ratings as the same size tire as another brand, assuming similar constructions, ie E rated tire vs E rated tire. 

 

Below is an example table for the OE tire size (if you have 20" wheels) for the new HD trucks. The "Single" row is what you want to pay attention to unless you have a dually. On this table, the rates are for the axle (2 tires), divide by 2 if you want to know the rating of an individual tire. 

 

If you look at the chart below 80psi will provide appropriate support for 7500 lbs on one axle, that's more than enough unless you are inappropriately overloading.

 

Now, each truck will obviously be different but just as an example, here are some numbers I pulled from someone who had weighed their new HD truck on a CAT scale with full fuel and a couple few passengers.

 

Front Axle: 5120lbs

Rear Axle: 3560 lbs

 

So for an UNLOADED truck, you can easily get by with about 47psi front, and 35psi rear. Now if you are always towing then it doesn't make sense to always be adjusting your tire pressure, and I would personally set my tires to match my towing loads. 

 

LT275/65R20 E
PSI		35	40	45	50	55	60	65	70	75	80	Maximum load & pressure on sidewall
kPa		250	280	310	350	380	410	450	480	520	550
LBS	Single	4160	4560	4950	5360	5700	6060	6390	6750	7080	7500	S	3750 LBS at 80 PSI
	Dual	7580	8300	9000	9880	10380	11020	11640	12280	12880	13660	D	3415 LBS at 80 PSI

 

 

What do you guys think? Do you guys follow Load and Inflation tables or do you keep your tires at Max PSI? Obviously running at 70+ psi all the time will affect the ride quality if you're not towing and don't need that much. 

Also keep in mind every tire size has it's own Load and Inflation table. so if you change tire sizes, the recommended pressures on your door will not be accurate. This applies on any vehicle. 

[Black02Silverado]

I don't have a HD but do have E rated tires and have kept them at 40psi all around and have 70k miles on them.  Michelin LTX M/S2s.  I do tow a 4k trailer monthly.

[aseibel]

Why would you keep them at max psi unless you are daily hauling the maximum weight allowed by your truck's configuration?

I would think most reasonable people would find the sweet spot based on their typical daily usage. Is your GVWR 15,000 lbs? Tires can usually support more weight than your truck's GVWR would allow, so no need to go up to 80psi.

[FirstAscent]

7 minutes ago, aseibel said:

Why would you keep them at max psi unless you are daily hauling the maximum weight allowed by your truck's configuration?

I would think most reasonable people would find the sweet spot based on their typical daily usage. Is your GVWR 15,000 lbs? Tires can usually support more weight than your truck's GVWR would allow, so no need to go up to 80psi.

Correct, and I completely agree. But I believe these HD trucks come from the factory, or probably dealer, at 70+ psi don't they? I'd imagine a lot of people never re-adjust it from how the dealer sets it. 

[swathdiver]

1 hour ago, FirstAscent said:

What do you guys think? Do you guys follow Load and Inflation tables or do you keep your tires at Max PSI? 

Too little air and they may not wear correctly.  

[saskfarmer]

I tried lowering mine from 70psi to 50psi but my low tire sensor comes on. My dealer won't lower the setting in the computer said it's a safety issue.

[FirstAscent]

1 hour ago, swathdiver said:

Too little air and they may not wear correctly.  

Correct, IF it's too little air for the current load. You obviously don't want to be at 45 PSI hauling a 17k trailer haha. Of course, I'm not a tire scientist so this is just my opinion

49 minutes ago, saskfarmer said:

I tried lowering mine from 70psi to 50psi but my low tire sensor comes on. My dealer won't lower the setting in the computer said it's a safety issue.

This is a good point, the TPMS sensors (or the computer reading the sensors I should say) are programmed to be looking at a drop in PSI. There is absolutely nothing unsafe with running at 50psi UNLOADED. The tires are rated for it. Dealers can lower the setting, whether they will or not is a different story. For sure a safety issue if you are towing but if you are daily driving and rarely hauling/towing then it would be much more convenient to have it set at a lower value.

 

There is also no harm in just running your tires lower and putting up with the TPMS light being on. Annoying yes, but harmful no. 

 

 

I think it's funny that my Jag SUV has a Standard and Light Load setting. With the push of a button I can select which mode I want to be in and it will adjust the TPMS setting. Light load sets it up for 34ish PSI, Standard setting is around 50 or so. This vehicle doesn't haul or tow but I can easily adjust this anytime I want. I keep it in the light load setting and my tires set to 34psi year round. 

This should be standard on HD trucks, or any truck for that matter! haha. 

[swathdiver]

1 hour ago, saskfarmer said:

I tried lowering mine from 70psi to 50psi but my low tire sensor comes on. My dealer won't lower the setting in the computer said it's a safety issue.

What pressure does the sticker in the door say to use?

18 minutes ago, FirstAscent said:

Correct, IF it's too little air for the current load. You obviously don't want to be at 45 PSI hauling a 17k trailer

The tires really only need enough air to meet the load capacity of the rear axle, assuming one is loading and towing within specs.  

[saskfarmer]

1 hour ago, swathdiver said:

What pressure does the sticker in the door say to use?

 

Front tires 60 psi    Rear tires 70 psi    This is on a 2020 chev 2500HD duramax

[Dunn]

better MPG fill those bitches up.....softer ride air them down....its always a tradeoff but were splitting hairs here, based off experience and time you just run em what you feel comfy at.....your getting anxious bro.....

 

depends on tire but run em at drastic pressures to feel what side of coin you like better, than dial them in.....everyones "feel" or " perception" could right on money or in completely different stratosphere than yours and everything in between.....

 

after awhile in new rig youll figure it out

[swathdiver]

7 hours ago, saskfarmer said:

Front tires 60 psi    Rear tires 70 psi    This is on a 2020 chev 2500HD duramax

Ok, I see their point.  They can't adjust the setting because the air pressure has to allow the tire to meet or exceed the axle weight rating.

 

But you may be able to fix this yourself.  A clone MDI2 or VXDIAG NANO with GDS2 software can do the job if/when they have the latest programming which includes your truck.  That I do not know.  Besides, with this tool you'll have full, dealership level diagnostics yourself.  

[KARNUT]

I always ran my KOs for ride comfort and spring rate when empty. Add air when using goose neck. My 3/4- one tons always had fuel tanks tool boxes etc. Even my cars and 1/2 tons ran less than max. It a little tougher now with air pressure sensors to go too low.


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[SkidooSteve12]

My monthly OnStar email said that my tire pressures were too low and needed action when they were more than 10 psi below the 60 psi for the front tires and 70 psi for the rear tires. But the TPMS alert never came on in the truck. They were down to 48 psi front and 58 psi rear from 60/70 that the dealer set them to because of the drop in temperature during the winter. Honestly I didn't notice any difference in the ride quality.....

[FirstAscent]

13 hours ago, Dunn said:

your getting anxious bro.....

 

after awhile in new rig youll figure it out

haha I'm anxious to get my truck but not concerned about tire PSI. This was just more out of curiosity what other people do since the dealers set them pretty high to account for actually hauling/towing. I already know exactly where I'm setting my tires at to start off with. I'll base it off of the curb weight + maybe 500 lbs and be good to go. I won't be hauling/towing anything for at least a few months so until then, I'll have them set for Unloaded. 

9 hours ago, swathdiver said:

A clone MDI2 or VXDIAG NANO with GDS2 software can do the job if/when they have the latest programming which includes your truck.  That I do not know.  Besides, with this tool you'll have full, dealership level diagnostics yourself.  

This sounds super handy. I'll have to look into that. 

[Booger T]

I've never had a problem with my dealer changing the settings on the tpms.