LeonBe

I have Hankook 265/60/18 110 Dynapro HT's on my 15 EB. I tow a 6700 lb travel trailer. The specs show a MAX PSI of 51. What should I be airing the tires when towing?

tsigwing

max

LeonBe

Thanks

csilwy

LeonBe - how well does your truck handle your travel trailer? My trailer is a bit lighter and was curious how the 2015 EB does with it.

LeonBe

I had no issues towing it. I have a Hensley Arrow WD hitch so I had zero sway and the power is more than enough. I used tow/ haul mode and it very rarely changed out of 6th gear. The Hensley is probably overkill but it was worth it IMO.

smokeywren

Tires must be cold (ambient temp) when you check PSI or add air. "Cold" means the tires have been sitting still for at least two or three hours, and preferably overnight. I park my rig so my air compressor hose will reach all tires on the rig, then check them the first thing in the morning


Trailer tires with ST prefix to the size = max PSI on the tire sidewall when the tires are "cold"


Truck rear tires = max PSI on the tire sidewall when the tires are "cold". So for you that is 51 PSI.


Truck front tires = you really need to weigh the wet and loaded rig on a CAT scale to get the weight on the front tires. Then apply the Tire & Rim Assn (TRA) load/inflation table. when the tires are cold. But if you can't find a TRA load/inflation table for your size tire, then I'd probably run about 35 to 40 PSI in the front tires when towing.

LeonBe

Thanks, I know they had to be cold when I check them, but I was not sure what pressure to run between the door label PSI and max PSI when towing.

11screw50

The psi noted on the door sticker should be correct for the maximum stated load of the vehicle.

Keep in mind, your rear axle is probably only rated for 3800lb (max tow may change that, not sure, hd payload does change it) which is only 1900 lb per tire. The Dynapro ATM in a 265/60r18 size has a max carrying capacity of 2601lb (which is reduced to 2364 lb when installed on a truck) at 41 psi.

Oddly enough, I did find one site that suggested that for an SL tire, the rating is at 35 psi and for an XL tire it is at 41 psi but the manufacturer can stamp a max pressure of 44 psi or 51 psi on either type.

This has some good information including charts:https://toyotires2-1524598101.netdna...s_20151020.pdf

Unfortunately, it does not list 265/60r18 in an XL even though Hankook does list theirs as an XL on their website. (It does not list my size (275/55r20) in an XL either) but at 35 psi, a standard load and an XL are rated the same and at 35psi they are rated for more than the axle rating.

Just remember, unless it is an LT, you have to divide the capacity at any pressure by 1.1 when installed on a truck.

Dirttracker18

No it is not, it is for the base weight of the vehicle or curb weight, not loaded.

When loading the vehicle the air pressure needs to go up. Technically you should weight the vehicle at each axle, use the tables to get the desired air pressure and inflate accordingly.

11screw50

Yes, you should weigh the vehicle and check the charts but I think you will find that with P-Rated tires in either SL or XL ranges, the 35psi noted on the door will result in more load carrying capacity than the axle ratings.

With LT's you need to start higher because they tend to carry less at 35psi than P-rated tires do. Most find that 45-50 psi (depending on the tire size and load range) is where they need to be to match the factory tire ratings.

There is no way the manufacturer would indicate a pressure that was for the base weight of the vehicle, it will never travel down the road empty, once the driver gets in, it is over the base weight. Add four more passengers about you can easily be over 1000lb higher than base curb weight.