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bka0721's avatar
bka0721
Explorer II
Oct 10, 2014

How often do you check your Truck's tire pressure?

How often do you check your truck tires and trailer’s Air Pressure carrying your Truck Campers?

Do you vary your diligence with the wheel type?

Tire Size and type?


A friend asked me about tire inflation and how often is too often in checking air pressure on our heavy weighted vehicles. Now, that my friends, is a really good question. Especially in regards to the recent discussion on 19.5” tires.

From my racing days, I learned one thing, the lighter the unsprung weight of a vehicle the easier it is to move a vehicle around and of course, the faster it will go. Well, that transfers to our trucks too. With my vintage racing, we often used Hallibrand Knockoff Wheels (spinners with pin lock). These special wheels were produced from Magnesium. Super light, but porous. Thus the issue of wheel porosity.

The lighter the material, typically the more porous, meaning air will permeate the wheels, thus slowly deflating the tire, if left unchecked. The Magnesium wheels were so porous, the tires would deflate in a few hours. The side effect of moisture laden air expanding, often helped with the loss of air, in these tires. Coatings and other additives were applied and blended into the moulding of these wheels, as well as modern wheels and tires. For lighter tires often loss air pressure as well, typically due to their reduced sidewalls and designs.

So with that, one might expect the ultra-expensive Carbon Fiber Wheels being the least porous, but who would want to spend more than $10k per wheel? As it is well known that polymer wheels have the best air retention, but lose favor for their lack of durability. Modern Aluminum wheels are still susceptible for air loss, over time, than their heavier counter parts, Steel. Newer science allows less porosity of Aluminum Wheels, but it is still an issue and needing more monitoring/air pressure verification. Especially when lower quality manufacturing is used and why the higher quality Aluminum Wheels are sought by Commercial Trucking, for their minimal porosity issues.


b

37 Replies

  • We check psi the morning we set out on our trip, doesn't vary much as we rarely have to add air unless I air down tires (for softer ride) after last trip out. Our 16" LT truck tires are capable of handling quite a bit more than what our rig weighs anyway, I just verify they are set above a certain load handling psi and try to keep them evenly aired up across each axle. Front axle psi is about 10-15 psi lower than rear in most cases when towing.
  • I check mine once in a while but it seems that the OEM pressure minder does a pretty good job.
  • Only because my camper is always on the truck and I run it at least once a week around town , I check every month or prior to any kind of trip other than around town.

    Actually, I'm thinking about the trying tire pressure monitors.
  • Lots of variables, Eric. You are wise to verify. Even altitude will vary air pressure and road temperature. We always had someone at pit out, to verify tire temps with an IR Gun.

    One thing I always remind others, is to be careful where you check your air pressure and make sure you keep caps on the valve stems. The reason is that dust, debris and dirt can lodge in the valve stem and be forced into the stem when airing up. I always carry a supply of valve stems and more than one stem remover and caps. Also, most cigarette air compressors will not inflate a 19.5" tire to a safe inflation level. Be sure to check your auxillary

    b
  • Pressure will vary greatly just based on outside air temperature.
  • Well I have noticed that there is a pressure loss in my 19.5s that is faster than with my 16s. Enough of a loss that I bought a quality digital pocket sized tire gauge just to verify that it is a real loss vs gauge accuracy issues. I had them at 100/85 when I left for my trip. 2000 miles (20 days later) it was 96,94.5/84.5,81.5. I have since reset them to 100/81.5 and will check weekly and before any trip. Wanted less in the fronts so I just matched to the lower of the two.
  • Each and every time we go out. which is twice a month year around.

    In Florida there is no off season.