Tire Pressure?

[BMW442]

Gearing up for our first trip. Do you usually top off the tires after loading camper? Set them at or just under max cold psi?

[DiskDoctr]

jadatis wrote:
If you give needed data , I will give a picture of my filled in spreadsheet in my answer with adviced pressure for your situation.

OP, the aforementioned spreadsheet is NOT any kind of authority or official info and only loosely make reference to real data.

Personally, I consider some of his previously "recommended inflation spreadsheets" to be...incorrect at best and dangerous at worst.

Make sure you do some research and reading before taking advice from this poster about his opinion of *safe* tire inflation.

[wintersun]

I always have the 4 tires at the recommended PSI per the truck manufacturer and this also corresponds at the rear wheels to the tire manufacturer's max PSI for maximum load rating.

Dumb to run with a heavy load and under inflated tires. There will be reduced load capacity. There will be more sidewall flexing and this wastes fuel and causes the tires to run hotter. There will be poorer road handling and possibly increased braking distance.

Tire pressures should always be checked "cold" which does not mean when the air temp is cold, but to have the tires sit for 3-4 hours (without direct sun on any of the tires) so the air temp inside the tire equalizes with the air temp outside the tire.

[jadatis]

If you give needed data , I will give a picture of my filled in spreadsheet in my answer with adviced pressure for your situation.

From Motorhome ( I asume its not a travel trailer or 5th wheeler)
Best would be seperate weighed Wheel( pair ) loads , second best axle loads weighed, but in lack of that we will have to do with the GAWR's and GVWR ( Gross Axle/Vehicle Weight Rating).
Maximum used speed , wich you wont go over for even a minute.
Configuration of Motorhome ( number of axles and total tires rear and front. GAWR's and GVWR mostly are on same plate as pressure advices in America, European cars must have a VIN-plate with it since about 1980.

From tires : Maximum load and AT-pressure ( wich is not the maximum pressure) but also speedcode of tire ( between J and Q )
Handy would be the sises of tire to check with Google if your 80 psi AT-pressure is realy the AT-pressure. Mostly this all can be found on sidewall of tire.

[BMW442]

Thanks for the info guys

We have michelin load range E tires and a light camper (1985 mini palomino popup)

I have a compressor at home so I was just gonna do it before we take off

[tony_lee]

Tires deform; they don't compress, so the air pressure remains the same regardless of how much weight you put on them.

Perhaps true - more or less, but the correct way to do it is to have your truck loaded as you would for the trip - including all passengers - and go and weigh all four corners if possible, and at least each axle, and use the tyre manufacturer's load-pressure tables to set the cold inflation pressure.

Rigs I have seen have shown tyre wear consistent with way too high pressures and this isn't good for tyre wear, handling, braking and especially ride comfort.

Once washboarding or rocky gravel is met, it is beneficial to drop the pressures to 80% AND drop the speed to at least 80% as well. The worse the surface, the lower the speed and the lower the pressure.

[DWeikert]

mkirsch wrote:
Before or after you load, doesn't matter. Tires deform; they don't compress, so the air pressure remains the same regardless of how much weight you put on them.

Only caveat I would put to this is how far you have to go to inflate your tires. If it's just a matter of pulling the air tank over to the truck, before or after loading doesn't matter. On the other hand, if you have to drive any distance to get to an air pump, it's best to air up before loading.

[c_traveler2]

For my set up I re-adjust my tire pressure after the camper is loaded, never do I go over max tire pressure rating label on the tire.

[mkirsch]

Before or after you load, doesn't matter. Tires deform; they don't compress, so the air pressure remains the same regardless of how much weight you put on them.

Max PSI is "safe" but not necessarily necessary. Without knowing what tires you have or how much weight you plan to put on them, this is what I would recommend, though. You will sacrifice some wear on the tires by doing it this way, but again, it is the "safe" way to go.

[Wheelholder]

My camper is pretty heavy. I run the max cold tire pressure for my "e" rated, which is 80#. This usually equates out to about 90# after running a while. It should not matter if your camper is loaded or not. The pressure within the tire will be very close to the same.

[DiskDoctr]

deltabravo wrote:
I put them at the PSI that is indicated on the door jamb sticker, which for my DRW 09 Silverado is 66 PSI front and 60 PSI rear, stock tire size.

....only applies with stock tires. No magic stickers can tell what tires you are running, which could be different from stock

[jimh406]

I set my tire pressure before loading the camper at the pressure I expect to run. That's not usually the max pressure. I think the only time I ran max pressure was when I had Es on a SRW.

[deltabravo]

I put them at the PSI that is indicated on the door jamb sticker, which for my DRW 09 Silverado is 66 PSI front and 60 PSI rear, stock tire size.

[RWDIII]

Depends on load and tire rating.
I put this info in signature line.
Would be nice to have some info!