19.5 Tire Pressure ??

I personally think the RV corner weight and tire pressure thing can drive you nuts (for no real/practical reason I can think of)...I run 80 all around (since day 1) and have no problems.

Eight years ago using Michelin’s RV tire maintenance manual (Google it) I weighed my MH and established 80# as the proper tire pressure for my 19.5” tires.

When I first took my MH to a truck service center they automatically increased the pressure to 100#. When I questioned them they knew nothing about the relationship between RV corner weight & tire pressure. I just got 6 new 19.5" tires for my Itasca MH from a large tire service dealer and they automatically put 100# in each tire. Again when I questioned them they knew nothing about the relationship between weight & tire pressure.

Remember the more pressure the rougher the ride. My old tires were 10 years old and had over 50,000 miles on them but had worn evenly and still appeared in good condition.

Dave

Johnny G1 wrote:
And you are gonna believe the RV manufacture as to the air pressure on the tire's, I wouldn't believe a thing that Newmar tells me after some of the stuff I found, talk about screw ups????

My same point, I can't believe what is on label inside as to the tires when new, the tires now are completely different and made in China.

I think I am going with feel of motorhome and seeing if tires are running hot, but I won't feel comfortable at 40 lbs under max pressure, I am going to start at 95 lbs and see what happens over time.

Just wished Samson had a weight rating at what pressure on the internet.

Hikerdogs wrote:
I would check with a dealer who sells Samson tires to see if they have an inflation pressure chart. Keep in mind the pressure sticker on the motorhome applied to the tires that were on it from the factory. Over the years tire construction and pressure ratings change. I'm relatively sure it didn't come from Ford with Samson tires. What was true in 2007 for a particular brand and model of tires that were originally installed on the motorhome may not be relavent for the tires you currently have on it.

Our 2001 F53 chassis came with Goodyear G670 tires size 245/70R19.5 load range F. The recommended tire pressure was 70 psi. A few months after we got our motorhome Goodyear sent out a bulletin raising the minimum pressure to 75 psi. In 2006 they chnged the tire construction and raised the pressure recommendations to a minimum of 80 psi.

If we had used the sticker on the door to determine tire pressure it would have been a minimum of 10 psi below the recommendation for current tires.

That's right these are not the tires and weight rating at time of new, these were new tires put on by dealer, I would think the pressure rating would be completely different at this point..

And you are gonna believe the RV manufacture as to the air pressure on the tire's, I wouldn't believe a thing that Newmar tells me after some of the stuff I found, talk about screw ups????

I would check with a dealer who sells Samson tires to see if they have an inflation pressure chart. Keep in mind the pressure sticker on the motorhome applied to the tires that were on it from the factory. Over the years tire construction and pressure ratings change. I'm relatively sure it didn't come from Ford with Samson tires. What was true in 2007 for a particular brand and model of tires that were originally installed on the motorhome may not be relavent for the tires you currently have on it.

Our 2001 F53 chassis came with Goodyear G670 tires size 245/70R19.5 load range F. The recommended tire pressure was 70 psi. A few months after we got our motorhome Goodyear sent out a bulletin raising the minimum pressure to 75 psi. In 2006 they chnged the tire construction and raised the pressure recommendations to a minimum of 80 psi.

If we had used the sticker on the door to determine tire pressure it would have been a minimum of 10 psi below the recommendation for current tires.

timmac wrote:
So my NEW 19.5 tires say 120 lbs max but the label for specs inside motorhome say tires front and back should be 80 lbs ??

40 lbs under tire manufacture pressure seems to low, so for now I put my tires at 95 lbs, am I to high or to low ??

:@:h

What would you do if the tires maker said max pressure was 200 lbs??

With the tires that came on the rig ( tire size) inflated to what it says on that placard....will allow your coach to carry the MAXIMUM AMOUNT OF WEIGHT it was designed for...no more..no less.

Running as much higher that the specified placard card gains you NOTHING

rgatijnet1 wrote:
If you have had good service at 95psi, why change?
Weighing your coach at all four corners only tells you the weight at that moment. As you drive you use fuel, shift water from fresh to gray/black tanks, add groceries, and add more clothes for a longer trip than a shorter trip.
If 95psi worked with your old tires, I'd stick with it.

I have not had the motorhome long enough to know what's the best pressure, when I got it home the pressure was around 80-85 lbs and drove nice but when I saw the tire pressure on the tires it says 120 lbs, so for now I put them at 95 lbs and will see if it rides harder or the same, 40 lbs under the tire manufacture max seems rather low and tires might run hot, maybe I will get one of those heat sensor guns and go from there.

As to what the rv label says inside was what Fleetwood had for tires when new, I think they were Goodyear, not sure because this RV came with new tires when I bought it 3 weeks ago.

I also understand different pressures for different weights but 40 lbs under max seems its getting to low of a pressure.

Also Samson tires has no where that I can find for correct pressure at what weights.

Reread the tire.. It does not say just 120 PSI max it says something like this.

Maximum load 5,000 pounds at 120 PSI max pressure

(note weight picked out of air and is used as example only)

The only way to insure proper pressure is to scale the rig, each wheel (not tire if you have duals but wheel) and use the tire maker's web page.

On trailers if you like you can over inflate a bit, but still I don't recommend it. Here is why.

With the proper pressure the tread lies flat on the road, WIth over inflation the center of the tread is on the road but the edges are not, this leads to loss of control and a rougher ride. Under inflate and teh center of the tread is not working as hard and what's worse the sidewalls are flexing more, this leads to a loud BANG and a wop wop wop and brand new plumbing and wiring and wheel well panels where the tire tore the (term deleted) out of your trailer.

As far as I can determine from lots of web research you DO need 4 corner weights. On each axle you use the weight for the heavier side. Do the weighing when completely loaded for travel.

Use the highest weight on each axle to check the weight/pressure (or Pressure/Load) table from the manufacturer for the model tire you have.

I did a write up on my research, link below in my signature.