Coach Weight/Tire Pressure

[VegasDogMan]

Just had opportunity to weigh my coach.

Here's what I have with Full Water/Fuel & Empty holding tank....

Front Axle - 14,806
Rear Drive & Tags - 29,480
Total 44,286

Prevost Placard says the following:

Front Tires - 7,500 Each @ 120 PSI = 15,000 Lbs
Drive Tires - 4,635 Each @ 80 PSI = 18,540 Lbs
Tag Tires - 5,545 Each @ 80 PSI = 10,910 Lbs

Total 44,450 lbs

My Tires - Michelin XZA-1 are rated as...
Single 9,090 Lbs @ 130PSI
Dual 8,270 Lbs @ 130PSI

or
Steer Axle = 15,220 @ 110PSI
Drive Axle = 24,280 @ 90PSI
Tag Axle = 13,340 @ 90PSI
Total 52,840 Lbs


Question is - Since tires can safely handle loads larger than what I'm currently running, can I load the coach above the Prevost ratings? How much more load can the coach safely carry?

Lee

[jello_jeep]

Vegas,


the short answer is no, not safely.

The tire ratings are only part of the picture, you still have axel limits, and all the other ju-ju that Prevost engineers into it.

I am sure Jon will weigh in with the more verbose reply, but thats my .02!


Good luck!

[Joe Cannarozzi]

Lee as far as the LAW goes you can go to 34000 on the back and 20000 on the steer. 54000 is max. legal for the way the axles on the bus are configured.

I'm pretty sure that some of these newer triple slide busses are getting right up against that limit.

I know that was not your question but just thought you would like to know.

[truk4u]

Dogman,

You should let us know the year and converter, that way others can help you out... Best bet is to put it in a signature then you don't have to type it each time..;)

[Jon Wehrenberg]

I think Dogman is LB, and if so he has a 40' Liberty

The Michelin site http://www.michelintruck.com/michelintruck/tires-retreads/load-inflation-tables.jsp will show the inlfation pressures for the tire size and weights being carried.

I am confused about the Prevost ratings. On my coaches the placard listed total weights per axle and the gross vehicle weight (which was less than the combined axle weight limits). Joe's answer was the highway legal weight limits.

I have never had Prevost placards which defined tire pressures because they would have no way of knowing how heavy the converter made the coach and how much stuff was put in it.

The short answer to the overloading question is No! Do not overload it.

[gmcbuffalo]

I agree with Jon, tire weight does not equate to axle weight. I would go back to the placard and read it again.
GregM

[Darl-Wilson]

I have a 97 Country Coach 45' XL. Prevost manufactured this vehicle on 4-1996.
I weighed the coach yesterday with full fuel, 1/4 tank fresh water and empty holding tanks. The lower compartments have the normal junk, including a small refer and a 120V compressor and associated equipment. The steer axle weighed 14,060, and the combination of the driver and tag axles weighed 31260.

In a dash compartment is a placard from Prevost and Country Coach. I have Michelin 3.15 80R 22.5 XZA2 Energy tires. My steering axle is rated 14,660, the drive axle duals are rated at 26,180 and the tag is rated 14,380. The coach GVWR is 47,000. I have my steering axle inflated to 120# (that's why I carry the 120V compressor) and I have all of my rear tires at 100#.

I know these pressures are a little high, however, the tires are rated to 130# cold. As a former long-haul truck driver (like 40 years ago) I would rather have a harsh ride rather than a blown steer axle tire. I am not over-inflated on any axle and maintain a 2,000 lb margin between the tire rating and the actual axle weight of my rig. Some might argue with this theory but it works for me. Any input to the contrary is welcome.

I hope these weights help some of those with similar coaches but it is really best to get each individual bus weighed.

Incidently, my 2001 Honda CR-V weighs 3,440 and that is only because I restricted my wife Martha to 1 1/2 hours at the Denio Flea market in Roseville, CA yesterday!

[Jon Wehrenberg]

Darl, You did not say what the actual weights were so we cannot compare the tire pressures you are using to what Michelin calls for. But, in the context of how we use our coaches the only thing you are likely doing by over inflating (if in fact you are) is adding a little extra wear to the center of the treads. Since we typically never wear out the tires, but change them because they aged out that probably is unimportant.

The only adverse affect may be some loss of handling properties but since you are probably not driving your coach at the limits of adhesion I doubt that is going to be a concern.

Darl, have you communicated with Michelin to ask their opinion on overinflation? I did relative to the aging of tires and posted their response a while back (they confirmed the five or six year replacement regardless of tread remaining) and found them to reply promptly. Somewhere they have a link for questions.

[dalej]

I just wanted to add that the added stress of rough bridges, railroad and some highways can not be
calculated so stay on the conservative side always.

Driving a bus that is well within it limits is so peaceful and fun to drive. But once you start thinking about
what if’s, e.g. low fuel, blown tire, it becomes a job.

When I had 12R’s on the steer axle back when we bought the bus, I always had thoughts of what if one
of the front tires blows. Since I put 315 on the steer, I only think about the next cup of coffee. ;)

[Jon Wehrenberg]

Silly as it sounds that why I am perfectly comforable replacing air bags, brake chambers, tires, batteries, etc. before they fail.

Some things such as a bad battery becomes an inconvenience, but some others could end a trip.

[VegasDogMan]

Guess I'll just run front tires at 110 PSI and rears at 90 PSI and enjoy the ride. I'm not overloaded and don't expect to be so in the future. May add 600 Lbs of floor tile but don't expect thats going to make much difference.

I may have to go on diet.

Lee