Correct air pressure

[rlschurman]

Having a disagreement with my brother over the correct air pressure for the tires on my windjammer. He said I should go by the sticker on the jammer which says 50 lbs. the tires say 85 lbs max I say the 85 lbs cold is best for the tires. Anyone care to weigh in on this discussion. BTW The tires are 225 70 r15 maxxis brand.

[brian372lok]

What are the rims rated for?

[babock]

Use this:

https://www.maxxis.com/trailer/trail...nflation-chart

[67L48]

Sweet, it's been a few days since we had a massive debate on tire pressures.

Make sure to ask a diesel vs gasoline question next.

[llr]

use the load inflation chart as suggested, however get scale weights 1st. if they are the same size as the stock tires the 50PSI is fine. If the stock tires where at max like many campers I would go 5-10 over for a safety margin.

Also unless you get individual wheel weights I would also go 5-10 over the chart as there is about zero chance the the load is perfectly balanced over all the tires.

[csyrell]

Originally Posted by rlschurman

Having a disagreement with my brother over the correct air pressure for the tires on my windjammer. He said I should go by the sticker on the jammer which says 50 lbs. the tires say 85 lbs max I say the 85 lbs cold is best for the tires. Anyone care to weigh in on this discussion. BTW The tires are 225 70 r15 maxxis brand.

I'm no expert on tires by any means. However, I do know that when travelling my TPMS shows my tires gaining air pressure as they heat up. Temps and Pressures can even be impacted by the Sun side of the trailer when parked, and especially when driving.

With that, I can't imaging wanting to start out at Max Pressure when the tires are cold. You have zero margin for when the tires heat up and pressure rises. JMHO.

[MillMitch]

I found this online on another forum, posted by someone in Canada (which i only mention in case the rules are different than the US). I didn't know this so wanted to share.

Re: How do I determine the max PSI rating for my rims?
Wheels are often stamped with the maximum air pressure to be used when mounting the tyre. This is usually less than the maximum pressure that can be used for normal inflation. The mounting process can lead to higher stresses in the wheel as the tyre bead has to be seated over a shoulder in the rim. Consult the wheel manufacturer or supplier to be sure.

My only other comment would be that Max PSI listed on tire is cold Max, correct? so presumably that takes into account the pressure increasing with heat.

[llr]

yes the sidewall is cold pressure and allows for the pressure increase do to use and air changes.

I believe that cold is defined as 70 degrees and I don't recall the change per 10 degrees (thinking 2-3PSI per 10) but if you fill way over or under 70 it should be adjusted

[Martsing]

So, I have been following this thread and have to ask for some clarification. I just bought four Endurance tires and they were inflated to 80psi when mounted. The placard on the camper says max 50 psi. Should I reduce the PSI to 65 ?

Enquiring minds want to know.

Marty

[BandJCarm]

Originally Posted by Martsing

So, I have been following this thread and have to ask for some clarification. I just bought four Endurance tires and they were inflated to 80psi when mounted. The placard on the camper says max 50 psi. Should I reduce the PSI to 65 ?

Enquiring minds want to know.

Marty

My guess is that the camper placard was based on lower rated tires than what you now have.

The tires you have, are the tires you have. Inflate them to what their max is, as stated on the sidewall. Underinflated tires cause blowouts, especially under load.

[Martsing]

Originally Posted by BandJCarm

My guess is that the camper placard was based on lower rated tires than what you now have.

The tires you have, are the tires you have. Inflate them to what their max is, as stated on the sidewall. Underinflated tires cause blowouts, especially under load.

Thank you very much for the response.

That was what my instinct said but since we have only been at this for two years I still consider myself a newbie

Marty

[llr]

under inflated is based on load, not sidewall max PSI.

I just went to GY Endurance, same size, higher load rating, my old tires had a 65PSI max and some weight margin but not much especially since tires are not loaded evenly so I am running 70PSI, max is either 80 or 85.

if you should always run max then it would just be inflate to XXX and the manufacturer would not have load inflation charts. also if you run much over the chart you may be riding on the center tread which will cause uneven tire wear and possible handling issues.

from the factory it very common to need to run max PSI as they use the minimum tire they can.

Some people have complained about things moving around in the camper more with the GY Endurance then stock tires. I suspect this is because the are running the max PSI instead of the recommended pressure. I don't have this issue.

[lbrjet]

Originally Posted by Martsing

So, I have been following this thread and have to ask for some clarification. I just bought four Endurance tires and they were inflated to 80psi when mounted. The placard on the camper says max 50 psi. Should I reduce the PSI to 65 ?

Enquiring minds want to know.

Marty

I would and have run 65 psi in my 80 psi tires for the last 4 years and 17K miles. My placard also says 50.

[LegacyFB38]

Originally Posted by 67L48

Sweet, it's been a few days since we had a massive debate on tire pressures.

Make sure to ask a diesel vs gasoline question next.

Diesel vs gas? No contest!

But seriously, what is the best oil to use in my tow vehicle?

[dankirk]

Originally Posted by LegacyFB38

Diesel vs gas? No contest!

But seriously, what is the best oil to use in my tow vehicle?

Olive oil... Extra virgin.

[DieselDrax]

Originally Posted by BandJCarm

My guess is that the camper placard was based on lower rated tires than what you now have.

The tires you have, are the tires you have. Inflate them to what their max is, as stated on the sidewall. Underinflated tires cause blowouts, especially under load.

Originally Posted by Martsing

Thank you very much for the response.

That was what my instinct said but since we have only been at this for two years I still consider myself a newbie

Marty

Inflating those tires to the sidewall PSI may actually be quite dangerous, the rims are also rated to a max PSI and inflating tires with a higher load rating to their sidewall PSI could cause the rim to fail if it isn't also rated for that much pressure as well. Most wheels should have a max PSI rating listed on the back side.

Personally, I would find the tire's load chart and inflate the tires to carry the trailer's GVWR. Chances are you'll find that pressure to be pretty close to what the sticker on the trailer says.

[jaherbst]

A few PSI less than max inflation printed on the tire when it's cold will always keep you out of trouble.

Placard on trailer is with standard OEM tires and not some aftermarket versions.

Jack

[DieselDrax]

Originally Posted by jaherbst

A few PSI less than max inflation printed on the tire when it's cold will always keep you out of trouble.

Placard on trailer is with standard OEM tires and not some aftermarket versions.

Jack

Again, that is not always true or safe.

If someone has load range E tires with max load at 80PSI installed onto wheels meant for load range C or D tires and the wheels have a max PSI that is well under 80PSI then you are putting yourself at risk of wheel failure.

Never exceed the PSI rating of the wheel, if you don't know what the max PSI rating of the wheel is then either find out or run at the pressure listed on the trailer placard, but beware that running a higher-rated tire at lower pressures needed to remain safe with wheel PSI may result in the tire not providing sufficient load capacity.

When in doubt, contact the wheel manufacturer and ask. Seems many folks either forget or don't know that wheels have both max load and pressure ratings.

[Airdale]

The tire inflation pressure guessing game. No one really knows, do they?

The best clue is, read your owner's manual.

[rockfordroo]

Seems odd that a reputable tire shop would install tires on a wheel that is not qualified for the full pressure of the tire, bu then again......