19.5" tire pressure recommendation

[STEVEBROOKS]

Hi all,

While my Bridgestone M729 245/70R19.5 tires and Rickson wheels are AWESOME for hauling my 5th wheel, they're really harsh to use around town and out on the road un-/lightly-loaded. For those with 19.5" tire experience, what's the lowest pressure to safely run those tires at?

Thanks!

Steve

 

[mpaulson]

Following. I’m new to 19.5’s too on my 2023 DRW. Going by the load inflation chart for my Firestones, it shows the G,F&E ratings and no where can I find info from there site as to if I can run my G rated tires into the F & E load rating/psi ranges. Right now I’ve gone down to 65-70 on the rear but I’ve only driven it less than 1,000 km since I got it new. Fronts I’m running 75 psi. I’d like to go as low as 60 psi in the rear, but these tires beads don’t seat like a LT truck tire and risk the beads moving from too low of pressure from what I’ve read.

 

[seafish]

As you probably know already, most all commercial 19.5 tires and wheels are NOT beadlocked.
I have run my Rickson forged aluminum wheels with Toyo commercial tires as low as 65psi and even then it really doesn't help with the ride.

If you can, the best, albeit most expensive solution is to run 2 sets of wheels...the 19.5 set fort owing and hauling and the 17" for arounf town. This works for me as I mostly haul in the dry months and use a set of 17" RT tires on the oem wheels for the winter moths when I beed them. Needless to say, the truck ride iMUCH better in the winter.

 

[Ozymandias]

No matter what pressure you are running - ride quality is only bad or worse.
The Load Index of these tires is simply much to high, their side walls much to stiff, for these light trucks - even without any air in them it would be still harsh.

The reason for me to sell them and settle for 18" rims and tires instead. Biggest money loss ever with this truck.

Since we have nice 18" & 20" rims and tires with the proper LI I always advice strongly against the 19.5" Combination. They have been great at the time the standard maxed out with 16 & 17 rims but that's a long time ago.

 

[STEVEBROOKS]

Thanks all. I really only use the truck now for hauling the camper, and I do have the stock set of tires/rims I can put on. I've never run the 19.5s at less than their max of 120 psi, so am just interested in trying to do so at the lowest-allowed psi. I don't expect any magical improvement in the ride no matter how low I go. As others can attest to though, the improvement seen with the 19.5s when hauling heavy is dramatic!

Steve

 

[Ozymandias]

Like said, consult the inflation chart from the tire manufacturer. There is for sure no reason to run it at maximum pressure. That's horrible.
You'll probably use the lowest pressure that the inflation chart calls for which will still be above your maximum GAWR.

 

[AH64ID]

The charts showed the minimum pressure for the 245/70R19.5 was 80 psi. I emailed Toyo and stated my loaded weights, they said I could go to 70 psi minimum.

The way any XX.5” tire/wheel seats the bead is different, and relies solely on air pressure to maintain the rubber against the rim.

I never found found the 19.5” ride as bad as people reported, but it sure was noticeable on dirt or rough roads.

How heavy is your 5th wheel to need 19.5’s?

 

[STEVEBROOKS]

Thanks again all. We really only use the camper to go to the dunes to ride the ATVs and use the sand buggy. Due to the remoteness of the dunes, we take a LOT of stuff with us [full propane tanks, water tanks, camper fuel tanks, race fuel jugs, riding gear, tools, stands, air compressor, a little food, LOTSA brews (NO Bud Light!!!!), about 14 types of weapons/ammo, you get the picture...]. In addition two the two ATVs inside the garage, we double-tow the buggy on a trailer behind the camper. The max of the camper alone is 18k, and we've gotta be way above that in real life.

And, yes, I know about the truck only being a 2500, but I can't bear to part with her. She's never been abused, but let me tell 'ya, every time she goes out she's puttin' in an effort...

Steve

 

[User113]

Years ago I was able to locate the inflation charts for my 265/70R19.5 Hankooks, and luckily downloaded them. Sometimes things like this are hard to find. I made a chart in Excel and printed a copy for my glove box. The chart states that my AH11 tires (steer) can carry 3,478 lbs per tire at 65 psi and 5512 lbs per tire at 116 psi. My DH01 tires (traction) list 3070 lbs per tire at 80 psi and a max of 5070 lbs at 110 psi. So I ALWAYS use the minimum listed pressures. It makes a HUGE difference in ride quality. As a bonus, these minimum tire pressures will handle 13,000 lbs.

 

[User113]

BTW, here is the load/inflation table for the OP's Bridgestones. Looks like it starts at 80 psi with a limit of 3,640 lbs.

 

[STEVEBROOKS]

THANKS for the info, User113!