Tire Pressure Question

[bglanning85]

So we have driven our Thor Four Winds a few thousand miles now and was looking at the tires in the driveway and at least one seemed a little low. I checked the pressure and it was at 46psi - and all of the others also showed as 46psi. My concern is the tire is marked with the PSI settings and shows Max as 80PSI cold. So is there a reason to leave them all at 46 or should I try and get them up a little closer to 80? These are Hankook tires all around.

Thanks,

Bob

[Lt Keefer]

Tire pressure that low is damaging your tires. They should be inflated to the appropriate weight for your motorhome.

[Gary A]

Hello, neighbor (I live in Waxhaw). My tires say 80 psi and I have 75 in the front and 80 in rear because that is what it states on the decal in the door jam.

[bglanning85]

Originally Posted by Gary A

Hello, neighbor (I live in Waxhaw). My tires say 80 psi and I have 75 in the front and 80 in rear because that is what it states on the decal in the door jam.

Thanks neighbor! - maybe they just never fully inflated since they all are exactly the same pressure? I will up them much like yours!

[Bob Denman]

It might not have been your dealer: tires so tend to lose some air over time...
But you are correct: the identical tries pressures does seem suspicious!

[ArrrV]

Unless I am misunderstanding the OP, the psi embossed on your tire is not the controlling number for your tire pressure setting--the manufacturer's posted placard (usually near the drivers seat) is what you should use as your tire pressure setting. Different models, will often have different posted tire pressures. You can use Hankook's tire inflation tables for any adjustments based on your corner and/or axle weights.

[Gary A]

Originally Posted by bglanning85

Thanks neighbor! - maybe they just never fully inflated since they all are exactly the same pressure? I will up them much like yours!

Up them to what your door jam decal states is my suggestion.

[bglanning85]

Originally Posted by ArrrV

Unless I am misunderstanding the OP, the psi embossed on your tire is not the controlling number for your tire pressure setting--the manufacturer's posted placard (usually near the drivers seat) is what you should use as your tire pressure setting. Different models, will often have different posted tire pressures. You can use Hankook's tire inflation tables for any adjustments based on your corner and/or axle weights.

Spot on ArrrV - Door says 75 front and 80 for rear! I have the front at 75 and the rear at China.......my gauge only goes to 75 so slightly above that is the word China! :-D Need a new gauge

Thanks to all for the advice - feel much better about the trip to the beach this week!

Bob

[Mustang46555]

Our RS26 came from the dealer at 46psi all around, when I went up to the pressures on the door sticker I noticed a slightly harsher ride on bumps. Gee I wonder why they were all low to begin with? Test drives???????? Hmmmmmmmm
Might be a little harsher on bumps but it did wonders for body roll in curves.

[bglanning85]

Originally Posted by Mustang46555

Our RS26 came from the dealer at 46psi all around, when I went up to the pressures on the door sticker I noticed a slightly harsher ride on bumps. Gee I wonder why they were all low to begin with? Test drives???????? Hmmmmmmmm
Might be a little harsher on bumps but it did wonders for body roll in curves.

Well at least I am not crazy! :-D Must be sent that way and they expect the dealer or buyer to know enough inflate them? Helping with the body roll will be an added bonus to a lil more air pressure - maybe even a lil better gas mileage I bet.

[The Gritz Carlton]

AND...going forward, don't wait till the "look low". Check them every time you head out or at least weekly while traveling. They can pick up a small nail on the road and develop a slow leak. If one tire on a dual tire set up gets low, it puts double pressure on the other one. This, combined with summer asphalt temps (upwards of 140 degrees), will cause overheating and separation. When this happens, the end result will be new tire $300....body damage to coach $1500.

[Mustang46555]

I kind of doubt either Ford or Thor would knowingly send a unit out with underinflated tires. Probably more of a dealer tactic to soften the ride of what in reality is a heavy duty truck chassis. But Gritz is correct, tire pressure should be checked before every trip and several times during the trip.

[Bob Denman]

I agree: The time that it takes to check them might just save you from a MUCH longer unplanned stop along the road!

[The Gritz Carlton]

A well known trick is for the RV dealers to let pressure out of the inside tires of a dual real wheel setup, which most of these models are. This gives it the appearance of inflation but going down the road will soften the ride. I've seen them deflated as much as 50%.

[Bob Denman]

That has got to affect the load carrying capacity quite a bit; don't you think?

[The Gritz Carlton]

Yes...those dealers...they really are concerned about that aspect. It's a sales gimmick to make the test drive seem cosmic.

[SammyC]

I have a 2016 Thor ACE 30.2. My decal at the drivers seat says PSI 80 and thats what I keep in them. Ive had no issues.

[Bob Denman]

Originally Posted by The Gritz Carlton

Yes...those dealers...they really are concerned about that aspect. It's a sales gimmick to make the test drive seem cosmic.

[Diemaster]

on this topic may i bring up another related? (remember im a OEM freak)
ive noticed that people get TPMS that show the pressures. what about the stock (ford E450 in my case) TPMS light on the dash? are they set to 46 to turn off the light b/c thats what a empty van needs? will the dash light come on on an over-pressure? is the range re-programmable to say 70-80 front 75-85 rear?

i had a KIA soul a few years ago. it was set to 34PSI. one PSI higher or lower the light came on. not sure how it didn't come on when i loaded the car up or over a bump in the road but it was a "smart" system. it was a pain in the ass and i eventually just put electrical tape over the light. however, in a RV, i would want that type of "smart" system.

[JamieGeek]

I doubt there are any OEM TPMS sensors in the tires and I doubt the software to even light the light is in the dash.