First LT tires I've owned, how much air unloaded and loaded? The door sticker says 65 front/80rear, is this loaded to the max (6000lbs front axle/7000lbs rear axle)? Somewhat less for unloaded, I assume?
What are you all running?
Also, I plan to run the beach (15mph max) both unloaded and loaded to the max, how much should I air down to?
Thanks for the help.
Rick
2015 F350 Lariat 6.7L PSD

 

I always take it the fuel door sticker is for close to max weight ratings. I know if I would run 65/80 on my truck with the stock tires you would have a hell of a time keeping it on the road when unloaded. Also if you put different size or rating tires on the truck the air pressure max can change.

The tires on my truck now are max 65psi. I usually run 58-60psi up front and 50-52psi unloaded.(I have a V10, diesel front ends are heavier) When loaded the rears are bumped up close to max and the fronts are usually left the same. In the winter when things get slippery I usually go lower. i need the extra rear traction regardless which lowering pressure helps.

You should experiment some with air pressure to see what you prefer and your truck likes. On the beach you could most likely air down to half max psi or so. Just be careful not to pop a bead or roll over the sidewall.

 

I have a set of Michelins and run them at 75 psi at all 4 corners. The tire wear pattern is normal and the truck rides and handles fine. These tires have about 30K on them and are about 50% worn.

Lower tire pressures might give a smoother ride but , from my experience at least, I'd run them at recommended inflation pressures.

Lou Braun

 

And, of course, run them much below the factory setting and you will turn the TPMS warning light on.

 

^^^ what he said....
but look up the load inflation charts for your tires here -->
Load & Inflation Tables | Michelin Truck
and you might see something like this so you know how to adjust them...
80 psi in the back of my 350 seems like it would be what the buckboard days were like it's so rough !

PSI . Max weight per tire
--- . -------
35 . 2,080
40 . 2,280
45 . 2,475
50 . 2,680
55 . 2,850
60 . 3,030
65 . 3,195
70 . 3,375
75 . 3,540
80 . 3,750

 

Presuming you have 4WD, lower than specified front tire pressures have been known to contribute to front end instability, or wobble, under braking or when hitting one wheel bumps at highway speed. That said, I run around 50 psi all round all winter. I only run the sticker tire pressures when doing a long highway run with my trailer.

 

When I ran Michelins, I had them at 70 psi all around. They could easily support the weight of the truck and I never had a problem with my truck wandering or the tires wearing funny.

 

when I had stock size michelins on my truck I ran 70 on all 4 corners all the time and bumped the back to 80 when towing really heavy. Now I have 305/70/16s and run them at 60 when empty and 65 when towing

 

I run mine in the low to mid 60s range (62-65psi). If I load the back or tow I'll bump up the rears to 70-80psi depending on how much I'm adding to the rear axle.

 

I ran 265/75/16 Michelin LTX M/S (load range E's) on my '03 F250 4x4 for a few years at the factory rated PSI's (55 front 70 rear), and never had any issues with driving stability or tire wear.

 

I run 275/70/18 load range E tires on my '06 F350 4x4 SRW and have had various tire brands. Unloaded, I inflate the fronts to 60 PSI and the rears to 75 PSI. Towing a trailer, the fronts are 65 PSI and the rears are 80 PSI. The tires are rotated every 5,000 miles and I've never had any issues with driving stability or unusual tire wear.