8 lug inflation pressures when not towing or hauling

[davepl]

What should I run for pressure in my tires (LT style) for pressure when just driving around with no load?

The tires have a max capacity at 65psi, since they're a truck tire, but that's a lot of pressure and makes for a pretty harsh rish (am I really thinking about ride quality in one of these? I guess so!).

Is it safe to run 40?

While I'm at it, the shop manual does not list (or I could not find) lug nut torque values. Where are they found (and what do they say)?

Maybe these are so basic they're in the owner's manual and not the shop manual, but I couldn't find either.

[Stocker]

40 is fine, you might also try 35. Do a chalk test initially, then monitor tread depth regularly. Tread depth gauges are cheap and you'll find wear patterns long before your eyes can detect them.

I'll be honest, I always torque the lugs on my other vehicles but never on my K20. I just cross-tighten them by hand until they are TIGHT. No problems in 39 years, knock wood...

[kwmech]

I run mine at 50psi and torque to 110lbs

[davepl]

Thanks! What's the chalk test? Draw a line across the tread and see what wears off first?

[72kool]

40 psi is a good pressure to run. The heavier tire needs more air to wear properly. 40/50 is what I run in my 10 ply tires empty.

As for wheel torque, I torque mine to 140. That is what all newer 7/8 lug gm vehicle torque spec is.

[Stocker]

Originally Posted by davepl

Thanks! What's the chalk test? Draw a line across the tread and see what wears off first?

Yup. A lot of guys swear by it to at least establish a baseline pressure.

[Mike C]

Bigger the tire, less pressure needed for the same load. I run the 8 lug 35 12.5 16.5 D series tires on my Jimmy at 24 psi for road work. The Mickey Thompsons that used to be on there I ran at 22.

I think I ran the 265 75 16 D rated tires on my old C2500 GMC at 40 psi unless I was hauling so good advice from the previous posters.

[Sicklajoie]

I run 45-50 all the way around.
With Michelins and a coil spring rear my truck rides very well for a 3/4 ton pickup.

[tdangle]

I typically run ath about 45 PSI and about the torque for the lug nuts I copied this from the Chevrolet truck service manual:

WHEEL NUT TORQUES-

10-30 Series

On a new vehicle or after the wheel has been changed,

the wheel nut torque must be checked at 100, 1,000 and

6,000 m iles and every 6,000 m iles thereafter.

Retorque wheel nuts to 55-65 ft. lbs. on 10 Series and

65 to 90 ft. lbs. for 20-30 Series models.

Heavy Duty Wheels on 30 Series

On a new vehicle or after the wheel has been changed,

the wheel nut torque must be checked at 100, 500, and

1.000 m iles and every 1,000 m iles thereafter.

Torque wheel nuts 200-250 lbs. ft. on 30 Series trucks

with 11,000 lb. rear axles, RPO H-22.