Tire Pressure unloaded

[JHC1]

What tire pressure are folks running when not towing or hauling? My 3500 specs are 80 psi in the back and 65 in the front Which makes for a stiff ride but my concern is tire wear. If I bring them down to around 50, I’ll have to deal with the warning lights so that’s another issue. Any advice? Thank you.

 

[H3LZSN1P3R]

What tire pressure are folks running when not towing or hauling? My 3500 specs are 80 psi in the back and 65 in the front Which makes for a stiff ride but my concern is tire wear. If I bring them down to around 50, I’ll have to deal with the warning lights so that’s another issue. Any advice? Thank you.

3500s don't have low tire warning 50 front and 35-40 unloaded rear is a good place to be

 

[JHC1]

Ok. Coming off of an F150 so I am learning. The dealer told me I would have to put up with a warning if I lowered the psi. Thank you very much.

 

[Riddick]

Definitely take some air out, it will make a huge difference. I personally run 50 front and 45 rear.

 

[AH64ID]

My truck is currently empty and sitting at 55/35. It’s supposed to snow a bunch and I’ll be driving around town empty so I’ll probably drop to 50/30.

Hit the scales and use the published load and inflation tables to determine the proper pressure for any load. I use the Toyo chart for all my tires.

Toyo Load and Inflation Tables

 

[JHC1]

Thanks. I have the Toyo document and figuring out how to read it. My tires are LT285/60R20 125/122R. What does the 125/122R mean? Load index front/rear?

 

[AH64ID]

Thanks. I have the Toyo document and figuring out how to read it. My tires are LT285/60R20 125/122R. What does the 125/122R mean? Load index front/rear?

Load index single and dual. R is the speed rating.

You will use the single row for that size. Pressure across the top of the chart and the weight listed is weight per tire, so double it for axle weight.

 

[H3LZSN1P3R]

Ok. Coming off of an F150 so I am learning. The dealer told me I would have to put up with a warning if I lowered the psi. Thank you very much.

Dealer is wrong, the 3500 only displays pressure no warnings. The 1500/2500 has monitoring with low pressure alert

 

[JHC1]

At 50 front, 45 rear or any lowering, how is the mileage? Running 80 in the rear and 70 in front i was getting almost 17. But i only have 500+ miles on the truck.

 

[Firebird]

55 front and 45 rear on my dually
50 front and 40 rear on my single wheel 6.4

 

[AH64ID]

55 front and 45 rear on my dually
50 front and 40 rear on my single wheel 6.4

I know it’s sold, but was that empty on the dually? Stock tire sizes? 55 seems low and 45 seems high.

55 psi on the LT235/80R17 is only good for 4,740lbs, and 4th gen CTD DRW front axles are heavier than that empty.

35 psi is a better empty DRW rear pressure. 45 psi is still enough air for a RAW of 7,480.

 

[JHC1]

Reading higher PSI for the front and lower for the rears but my stickers show 65 front and 80 psi in the rear tires (SRW). I assume those psi are for loaded. I would like to air down for comfort but also achieve decent mpg when unloaded.

 

[AH64ID]

Reading higher PSI for the front and lower for the rears but my stickers show 65 front and 80 psi in the rear tires (SRW). I assume those psi are for loaded. I would like to air down for comfort but also achieve decent mpg when unloaded.

I’ve never noticed an appreciable difference in fuel economy running the proper pressure vs max pressure.

 

[H3LZSN1P3R]

I’ve never noticed an appreciable difference in fuel economy running the proper pressure vs max pressure.

Exactly but way too low pressure will hurt mpg

 

[Firebird]

I know it’s sold, but was that empty on the dually? Stock tire sizes? 55 seems low and 45 seems high.

55 psi on the LT235/80R17 is only good for 4,740lbs, and 4th gen CTD DRW front axles are heavier than that empty.

35 psi is a better empty DRW rear pressure. 45 psi is still enough air for a RAW of 7,480.

Yes, those pressures were completely empty

 

[CdnHO]

My truck is currently empty and sitting at 55/35. It’s supposed to snow a bunch and I’ll be driving around town empty so I’ll probably drop to 50/30.

Hit the scales and use the published load and inflation tables to determine the proper pressure for any load. I use the Toyo chart for all my tires.

Toyo Load and Inflation Tables

What he said. I use the tables for both the truck and the trailer. Figure the tire manufacturers know what they are doing.

 

[AH64ID]

Yes, those pressures were completely empty

Any funny wear from running the fronts underinflated?

I’ve read posts from several folks that say anything less than 80 psi on the front of DRW’s with stock sizes produces uneven wear.

 

[Dinky503]

Tire pressure will change depending on brand of tire and size. For wear and comfort I do a tire caulk test and seems to work great for me. I have toyo at3s 35x12.5r18 F-rated, I run 63 front and 58 rear empty.

 

[AH64ID]

Tire pressure will change depending on brand of tire and size. For wear and comfort I do a tire caulk test and seems to work great for me. I have toyo at3s 35x12.5r18 F-rated, I run 63 front and 58 rear empty.

Size yes, brand no. A given size and LI will be the same regardless of brand.

The chalk test works in a pinch, but it’s antiquated now that we have load and inflation tables on the internet. Thats evidenced by your tires having that much pressure. Empty.

 

[Dinky503]

Size yes, brand no. A given size and LI will be the same regardless of brand.

The chalk test works in a pinch, but it’s antiquated now that we have load and inflation tables on the internet. Thats evidenced by your tires having that much pressure. Empty.

Ok brand was the wrong term. What ply and rating and size. You can use a chart for sure or do the math on % of max load. I just do the caulk test and make sure the tire has even contact.