Tire Pressure on TV and RV...Help Please!

[bayou316]

Ok folks. Need a pretty quick answer please.

2011 Ford F350 dually. Max air pressure is 80 PSI.

2011 Excel Limited dual axle. Max air pressure 120 PSI.

How much is tow vehicle and RV?

Thanks....

[Still Working "NOT"]

$175,000.00

[SlocanPaul]

I'm assuming you want the tire pressures for each. You would be safe to go with whatever the tire manufacturer has stated on the sidewall of the tires.

[bayou316]

Quote:

Originally Posted by Still Working "NOT" $175,000.00

Almost...I guess I left off a couple words on my question. What would you recommend for air pressure on the TV and RV?

By the way, you were a few thousand off.

[bayou316]

Quote:

Originally Posted by SlocanPaul I'm assuming you want the tire pressures for each. You would be safe to go with whatever the tire manufacturer has stated on the sidewall of the tires.

Yes sir I am. My English and typing is a little off tonight. So you recommend putting in the max pressure on the tires sidewalls?

Correct?

[Still Working "NOT"]

Quote:

Originally Posted by bayou316 Almost...I guess I left off a couple words on my question. What would you recommend for air pressure on the TV and RV? By the way, you were a few thousand off.

I figured but the SA came out in me. I would run near 100 psi to 110psi in fifth wheel and 80 psi on the TV. Get a weight when loaded on the fifth wheel, if at max GVW run close to max psi. Lighter weight, I would lower psi for smoother ride. I run 110 psi on my Wild Cargo and very seldom have things throwed around in it but I have not weighed it either.

[azloafer]

Quote:

Originally Posted by Still Working "NOT" $175,000.00

Good one!

[BryanL]

Start with the max psi specified on the sidewall.

Check tire temperatures while on the road with an IR thermometer. If they consistently run under 100F then you might consider letting a bit of air out. If they run over 120F then you need more air or a tire (and wheel) that can handle more weight.

Note that using weights and charts and tables can sometimes provide good advice but are a secondary or tertiary measure. Temperatures are a primary measure and (nowadays) very easy to obtain with reasonable accuracy.

It is always a good idea to take a walk around the rig on break with an IR doohicky to see if temperatures of tires and hubs are OK. I have found broken brake springs and tires with nails in them this way early enough to minimize damage.

[LindaH]

The best way to set tire pressure is to weigh your setup...each tire position is best, but at least each axle.

Then get out the tire manufacturer's inflation guide and set tire pressures according to actual weights (all tires on the same axle should be inflated to the same pressure).

On our fifth wheel, we have the tires set at 80 PSI (the maximum for our 16" tires) because we run close to the GVWR. On the truck, we set fronts at 60 and the duals at 65 per tag on the driver's door (which, according to the tire manufacturer's inflation guide give us more weight-handling capability than the front and rear GAWRs).

[BryanL]

re: "The best way to set tire pressure is to weigh your setup" -- there are many reasons why this is not necessarily "best" - I provided two. A bit of brainstorming could come up with a few more rather easily, I think.

But it is the customary method and the one that is easy for manufacturers as they can create specifications and tables and charts for how to use their product when they are many miles away from your rig.

[BSmith01]

Quote:

Originally Posted by BryanL Start with the max psi specified on the sidewall. Check tire temperatures while on the road with an IR thermometer. If they consistently run under 100F then you might consider letting a bit of air out. If they run over 120F then you need more air or a tire (and wheel) that can handle more weight. Note that using weights and charts and tables can sometimes provide good advice but are a secondary or tertiary measure. Temperatures are a primary measure and (nowadays) very easy to obtain with reasonable accuracy. It is always a good idea to take a walk around the rig on break with an IR doohicky to see if temperatures of tires and hubs are OK. I have found broken brake springs and tires with nails in them this way early enough to minimize damage.

Bryan, where are you getting you're facts on heat readings and when to inflate or depressurize a tire? I have seen three IR guns by the same manufacture give three different readings. I do know that fully charged batteries are the best. When I read an IR reading I also know what the ambient temperature is so if it is 100* degrees ambient and I read over 120* after traveling some time I would not get concerned.

[BryanL]

re: "I have seen three IR guns by the same manufacture give three different readings." -- by how much? folks often get obsessed with precision and loose track of both the accuracy needed and the accuracy of an actual measure.

When it comes to checking tires and mechanical parts, the first indicator is relative temperatures so as long as the temperature measures are consistent, absolute accuracy isn't much of an issue. As for the needed accuracy of these measures, 5F to 10F is plenty good enough, I think.

As for where I get my facts, they are readily available for any critical reader as well as an objective observer. There is also easily understood rationale as heat comes from tire flex and higher pressures reduce tire flex. (in re the accuracy thing- that is a major factor in the charts and tables approach as the accuracy of weight on a tire, especially in use over time, is an interesting topic in itself)

Check the temperature of your own tires while on the road as I suggested. You'll see.

but I know these ideas are different from established paradigms and I also know that when challenges come in, they are usually followed by the ad hominem rather than research. That means it is time for me to retire in favor of civility in discussion ...

[bayou316]

Hey..I appreciate all suggestions and methods of figuring this out. All are appreciated greatly.

We will "get er done".

Thanks again.

[davydee]

Quote:

Originally Posted by bayou316 Hey..I appreciate all suggestions and methods of figuring this out. All are appreciated greatly. We will "get er done". Thanks again.

I'd be interested in what you finally end up with. When we had an 36 LGKE Excel, I ended up running about 105 to 110 on Michelin XTAs. Any higher and I'd launch furniture. Even fully loaded, we had less than 14,000 lbs on the axles and the street side tire on the front axle only carried around 3,500 lbs. Thanks!! David