Tire Pressure

patmcwhirter · 10-19-2013, 06:53 AM

I am a new owner of a 24S and I can see that suspension upgrades are needed right out of the box. I have ordered the Hellwig sway bar and will make a decision on shocks after I install it. Because of this I have come to the conclusion that the sprinter chassis was designed for a lighter cargo van and is maxed out with the motorhome weight. So I am now pondering tire pressure and wondering if it should be increased also. I would appreciate any thoughts you have on this, and would like to know if anyone agrees and has increased tire pressure, and what were your results in handling and increased MPG.

Ford Idaho · 10-19-2013, 07:25 AM

Over inflation is never a good idea.
You can upgrade the tires to a heavier ply rating.

Ida Ratherbe Camping · 10-19-2013, 08:15 AM

Never exceed the pressure rating on the the tire side wall.

hkreck · 10-19-2013, 09:56 AM

Patmcwhirter

I have a 24S also, I have my tire pressure set at 65 PSI on all the tires and have 15000 mile on my Solera. The tires are all evenly worn and I have had no problems with them. The tags on the cab states for the front tires to be 57 PSI and the rear 61 PSI and side wall on the tires states 80 PSI max. So I'd just go with what you think is best up to that 80 PSI. I did upgrade the sway bar and it does improve the handling a great deal still thinking about the shocks?:-} Maybe next year on those. Good luck with your Solera the DW and I love ours.

patmcwhirter · 10-19-2013, 12:38 PM

No I would never exceed the 80lbs the tires are rated for but I am thinking like the post above 65 or 70 might be more inline with the weight we are carrying on the chassis instead of the recommended 57 and 61 lbs. Thanks

Taylorgso · 10-19-2013, 02:46 PM

I Run 65 PSI cold pressure in mine - that pressure will increase once on the road from friction to around 75psi, but I never let it exceed 80 psi.

BarryD0706 · 10-19-2013, 03:45 PM

Quote:

Originally Posted by Taylorgso

I Run 65 PSI cold pressure in mine - that pressure will increase once on the road from friction to around 75psi, but I never let it exceed 80 psi.

It sounds like you are adjusting the pressure once the tires get hot? You shouldn't do that.

Ford Idaho · 10-19-2013, 04:08 PM

Quote:

Originally Posted by BarryD0706

It sounds like you are adjusting the pressure once the tires get hot? You shouldn't do that.

Agreed, after the tires cool off the PSI will return to normal.

OldCoot · 10-19-2013, 04:48 PM

Quote:

Originally Posted by BarryD0706

It sounds like you are adjusting the pressure once the tires get hot? You shouldn't do that.

As long as he re-inflates them to the right pressure when cold, it shouldn't hurt a thing. Just more work.

BarryD0706 · 10-19-2013, 05:06 PM

Quote:

Originally Posted by OldCoot

As long as he re-inflates them to the right pressure when cold, it shouldn't hurt a thing. Just more work.

If they were at the right cold pressure (which is the only pressure that matters), and he lets air out of them, then they are under-inflated at that point, period.

OldCoot · 10-19-2013, 05:25 PM

Quote:

Originally Posted by BarryD0706

If they were at the right cold pressure (which is the only pressure that matters), and he lets air out of them, then they are under-inflated at that point, period.

Not true, as long as they are at max sidewall pressure they are not underinflated at any point as long as the load doesn't change.

BarryD0706 · 10-19-2013, 05:30 PM

I guess we'll just agree to disagree. Perhaps Tireman9 can educate one of us.

TURBS · 10-19-2013, 05:40 PM

Quote:

Originally Posted by BarryD0706

I guess we'll just agree to disagree. Perhaps Tireman9 can educate one of us.

For example my silverado tire pressure door sticker recommends 80 rears and 60 fronts what does this mean for me ?

BarryD0706 · 10-19-2013, 06:02 PM

It means you have different load requirements on the front vs back tires.

I will admit to being confused by this. I see OCs point that 75 pounds is 75 pounds no matter what the temperature is, so unless a hot tire needs more pressure to support the load than a cold tire does, what OC said makes sense. But I've always heard never to let air out of a hot tire because you think it's over-pressure.

OldCoot · 10-19-2013, 06:09 PM

Quote:

Originally Posted by BarryD0706

It means you have different load requirements on the front vs back tires.

I will admit to being confused by this. I see OCs point that 75 pounds is 75 pounds no matter what the temperature is, so unless a hot tire needs more pressure to support the load than a cold tire does, what OC said makes sense. But I've always heard never to let air out of a hot tire because you think it's over-pressure.

Just means that you need to add air when the tire cools. Makes no sense to me to deflate a hot tire, but if that's what the man does, it can't do any harm as long as he re-inflates when the tires cool. Will say this, over inflating hot tires will definitely stretch them. We used to over inflate tires on our race car and set them in the sun to stretch them. We could get the circumference to change by as much as 3"-4" over stock, which is how we got "tire stagger".

Taylorgso · 10-19-2013, 07:10 PM

So you're saying if I set preferred cold pressure and pressure builds to 85psi on a hot day (exceeding stated sidewall pressure) I should run them at that pressure? I disagree... But to each his own. I've blown tires in the past running them at excessive pressure when hot.

BarryD0706 · 10-19-2013, 07:28 PM

Quote:

Originally Posted by BarryD0706

...
I will admit to being confused by this. I see OCs point that 75 pounds is 75 pounds no matter what the temperature is, so unless a hot tire needs more pressure to support the load than a cold tire does, what OC said makes sense. But I've always heard never to let air out of a hot tire because you think it's over-pressure.

I figured it out. I was right the first time.

If 75 is the right cold pressure, the tire manufacturers know that the running pressure of the tire is going to be more like 82+, and THAT is the pressure the tire needs for the load. If you let air out of the tire, back down to 75, the tire is under-inflated for the load.

In other words, a hot tire *does* need more pressure for the load: the pressure they knew it was going to be at when it got hot.

BarryD0706 · 10-19-2013, 07:30 PM

Quote:

Originally Posted by Taylorgso

So you're saying if I set preferred cold pressure and pressure builds to 85psi on a hot day (exceeding stated sidewall pressure) I should run them at that pressure? I disagree... But to each his own. I've blown tires in the past running them at excessive pressure when hot.

It's not "to each his own". This is not subjective. There is a factual answer to this. Tireman9 will be able to tell us what that is.

OldCoot · 10-19-2013, 07:32 PM

Quote:

Originally Posted by BarryD0706

I figured it out. I was right the first time.

If 75 is the right cold pressure, the tire manufacturers know that the running pressure of the tire is going to be more like 82+, and THAT is the pressure the tire needs for the load. If you let air out of the tire, back down to 75, the tire is under-inflated for the load.

In other words, a hot tire *does* need more pressure for the load: the pressure they knew it was going to be at when it got hot.

And the source of that objective evidence you are quoting?

Taylorgso · 10-19-2013, 07:37 PM

Everything on these forums is subjective. You do it your way & I'll do it my way. I am not going to inflate my tires to a cold pressure which will allow the pressure to increase above the stated sidewall pressure at highway speeds. Never said I would let air OUT of the tire.

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