G670 Tire Question

[awwall]

My Georgetown came with Goodyear G670 245/70R19.5 tires. My wall plate in the coach says to inflate to 82psi. I have not weighed the coach yet, but looking at the Goodyear inflation chart for these tires, 80psi is the absolute minimum.

Was curious as to what others are running for tire pressure? My 351ds is what I consider loaded average.

I will get around to weighing.

[TURBS]

Originally Posted by awwall

My Georgetown came with Goodyear G670 245/70R19.5 tires. My wall plate in the coach says to inflate to 82psi. I have not weighed the coach yet, but looking at the Goodyear inflation chart for these tires, 80psi is the absolute minimum.

Was curious as to what others are running for tire pressure? My 351ds is what I consider loaded average.

I will get around to weighing.

What's the max inflation on tire sidewall ?

[awwall]

Max is shown as 110psi

[TURBS]

Originally Posted by awwall

Max is shown as 110psi

I figured it might .
We have a trailer that has 19.5 tires and we run straight up 100.

[Iggy]

Do they look like they are underinflated?
If you want to know for sure you will have to weigh the rig and compare that weight with the one one the wall. Then you will find out what your need to do.

Asking here is will just give you suggestions.

My wall plate says 90 psi for mine and max is 110 psi on the tires.
So if I question that I must start with a motrohome weigh in at a CAT scale.

[awwall]

Iggy, I fully intend on weighing, just have not had the opportunity yet. I just wanted a "feel" from others on what they were running. I had looked at Goodyear charts and noticed the min psi on my tires was 80 and FR stated 82 as recommended. I just wondered why the recommended was so close to minimums.

[Iggy]

Originally Posted by awwall

Iggy, I fully intend on weighing, just have not had the opportunity yet. I just wanted a "feel" from others on what they were running. I had looked at Goodyear charts and noticed the min psi on my tires was 80 and FR stated 82 as recommended. I just wondered why the recommended was so close to minimums.

What is your GVW and which weight is your chassis?
Now much weight for the front tires?
Here is my data plate if you want to see.

[Los Popes]

awwall,
There was a thread about a year or so ago about tire pressures for Georgetowns - do a search and you will find it.
It is important to know the weight of your rig - also weigh the corners - and it sounds like you will get around to weighing.
I too have 19.5s on my Georgetown and I run my tires at 90-91 PSI.
Good luck,
Adam

[kenandterry]

The important thing to remember with tires and their pressure.............

A tire size and pressure is obviously suggested as a tire of choice by the manufacturer for their application.........motorhome or trailer. Don't think that your rig is the only one for the tires in question. Motorhome tires and trailer tires would never typically be interchangeable, even if they do have the same tire dimensions. The maximum pressure listed on the sidewall is for the tire itself...........NOT the pressure you should inflate to because it is on your rig. Refer to the placard by your manufacturer for your rig as to what pressure you should run.

[mbtelguy]

Iggy
Just curious, your axles are rated for a total of 23000 lbs and yet your GVWR is only 22000 lbs. On my 378 the total axle ratings are equal to the GVWR.

Do you know why the GVWR total does not equal axle rating ?
Gary

[OldCoot]

Originally Posted by awwall

My Georgetown came with Goodyear G670 245/70R19.5 tires. My wall plate in the coach says to inflate to 82psi. I have not weighed the coach yet, but looking at the Goodyear inflation chart for these tires, 80psi is the absolute minimum.

Was curious as to what others are running for tire pressure? My 351ds is what I consider loaded average.

I will get around to weighing.

If it were me and the min is 80# and the max is 110#, I would run 100# +/- 5#. FR is concerned with the ride and could care less about the wear. Running close to max will get you max mileage and minimum wear and you will probably not even notice the difference in ride. Running close to max air will also give you the best stability driving.

[bend302]

I run 90# min on my 19.5 tires,. In hot weather they will go up close to 100#.

Bill

[Iggy]

Originally Posted by mbtelguy

Iggy
Just curious, your axles are rated for a total of 23000 lbs and yet your GVWR is only 22000 lbs. On my 378 the total axle ratings are equal to the GVWR.

Do you know why the GVWR total does not equal axle rating ?
Gary

I'm no expert but here is all my numbers for my 378TS
2012 Georgetown XL 378TS on 53 Chassis –
22,000 lb GVWR chassis
Bare chassis weight 6,792lbs
Wheelbase 242.3 “
15,208 lbs Max Payload
26,000 lb GCWR
Michelin XZE Tires 235/80R 22.5" max 110 psi
Single tire max 4,675lbs at 100 psi. (Mine are at 90 psi)
Dual tires max 4410 lbs at 110 psi. ( Mine are 90 psi)
Max front axle max weight 8,000lbs/2 = 4,000lbs max per tire
Max rear axle max weight 15,000lbs/4 = 3,750lbs max per tire
Max tow 4,000lbs

Lots of data that does into the proper tire psi.

You can see your chassis spec in the attached 2012 F53 Ford Document

[mbtelguy]

Iggy
Part of Note #2 seems to say that the total GVWR should equal the sum of the axle ratings. See below for quote from note

"Front and rear GAWRs will, in all cases, sum to a number equal to or greater than the GVWR for the particular vehicle.
Maximum loaded vehicle (including passengers, equipment and payload) cannot exceed the GVW rating or GAWR (front or rear)."

I wonder which is correct ?

Gary

[Iggy]

Originally Posted by mbtelguy

Iggy
Part of Note #2 seems to say that the total GVWR should equal the sum of the axle ratings. See below for quote from note

"Front and rear GAWRs will, in all cases, sum to a number equal to or greater than the GVWR for the particular vehicle.
Maximum loaded vehicle (including passengers, equipment and payload) cannot exceed the GVW rating or GAWR (front or rear)."

I wonder which is correct ?

Gary

I have no idea. My head hurts.
Keep the tire pressures as it sasy and drive it is what I'm doing.

[norwood12800]

When I had my 2012 378TS front end alignment done at a truck tire pro shop they said the wall information was wrong. You should go by what is on the tire. They put mine up to 100# each.

[Iggy]

Originally Posted by norwood12800

When I had my 2012 378TS front end alignment done at a truck tire pro shop they said the wall information was wrong. You should go by what is on the tire. They put mine up to 100# each.

That has to ride harder as well as more road noise.
If he said it was wrong why didn't he take it up to 110 psi?
Where did he come up with that number by magic?
He has no idea the weight of the motorhome unless he weighs it.

How many miles have you driven at 100 psi?
What is the difference?
Is it more stable at the campgraound?

[awwall]

Iggy, my head hurts also. I have been all over looking at tire pressure information and it does give you a headache. Great postings here and I appreciate the info.

Like I said earlier, my main concern is the fact that the placard in the coach says 82 when the tire manufacturer says 80 is min. I fail to understand why FR would want to run the tires at min pressure.

Maybe Dunnc is on to something with his statement.

[Falcon35]

I think if you check here it will give you all the information you will need.

The Inflation Loading - Goodyear RV

On the right side it has a link to the Inflation Table