2002 E450 Superduty tires

txnese wrote:
...I took it to weigh station right before the trip and it was a hair under 13,000 lbs total. That includes full gas tank, full fresh water tank, 5 passengers and all our junk for a 2 week trip...

You weighed it correctly, full of people, water, gas, and all that Stuff. Weigh Station usually gives you Axle Weights. Did you get those, or only the Total? If you go to a Travel Center (21st Century PC for Truck Stop) that has a CAT Scale, it'll give you three weights called Steer (your front axle), Drive (rear axle) and Trailer (any trailer or vehicle you're towing). All for about $10. They can't give you Corner Weights like some of the RV weighing fests, and like Michelin uses in the RV version of their tire load/pressure chart. Michelin apparently feels that more RV's than trucks are loaded unequally side to side.

With Michelin's Corner Weights, you'd set the entire axle according to the heavier side (not average or the lower side). The point made above, that Axle Weight could be OK but not one side, can surely happen, but most of us find Front and Rear Axle Weights to work out OK.

Linc,

How much of those 13,000 lbs. was on the 4 rear dually tires?

It's of course important to get detailed enough RV weight data to make sure no tire is over-loaded. Dividing the rear weight by 4 gives an approximate estimate of the weight on each rear tire. Dividing the front weight by 2 gives an approximate estimate of what's on each front tire. Some RV owners even get each corner of their RVs weighed individually for more accurate estimates of each tire's loading.

Large Class C motorhomes can often have their rear weight be too much for the type of rear tire being used and/or the pressure being used in those tires.

I've got a 30ft. I took it to weigh station right before the trip and it was a hair under 13,000 lbs total. That includes full gas tank, full fresh water tank, 5 passengers and all our junk for a 2 week trip. We also took out the RV queen mattress and replaced it with a King size mattress, no box.

txnese wrote:
I have BFGoodrich Commercial T/A All Season 2 from Discount Tire. 6,000 mile road trip and no complaints from me.

Is your class C a 31ft model running at the max weight on the rear tires? There is a big difference between a 31 footer and a 24-26ft class C.

I have BFGoodrich Commercial T/A All Season 2 from Discount Tire. 6,000 mile road trip and no complaints from me.

My WBO View had a set of Firestone Transforce HT LT225R75/16 tires on it, dated late 2012 when I purchased it in Sept of 2015. They worked well but the broker (for the estate of the deceased owners) had used tire shine on the sidewalls and it sat for a while on their lot. I have had several tire people tell me this caused the fine checking of the sidewalls that these tires had after I bought it. You cannot get the tire shine off, no matter what you use, and it is nasty when you handle the tires. I ended up scrapping the tires in the summer of 2017 due to this and installing a set of Michelin MS2 tires. I did move a rear inboard with no sidewall checking, to the spare position and scrapping out the new/original 2006 Michelin spare.

I considered a new set of the Firestones, or possibly Bridgestones or Toyo tires, but in the end I got the Michelins thru the FMCA advantage program cheaper than any deal a tire dealer was willing to make on any other tire. The Michelins ride about a thousand precent better than the Firestones did, and that made me much happier.

Charles

From the info posted above, the Michelin Tire Book link showed 225/75 needing 10.4" of Dually Offset, and 235/85 needing 10.6" or less than 1/4" difference. Not saying I'd try it, but there's the spec and the difference.

Agree on the Transforce HT tires. Haven't heard anything but good about them.

Lots of great info. We have been very content with the Firestone transforce HT. No issues, good even wear.

John, great informative comments in two of your posts above.

I was kindof amazed years ago when I noticed that 215/85R16 LRE tires were taller than 225/75R16 LRE tires - but still spec'd at the same load carrying maximums. What got me looking into it was that traveling friends of ours had the 215 size on their Ford chassis Class C, while my newer Class C came stock with the 225 size .... so I thought that their rig was "under-tired" relative to mine. So....the next time I re-tired our Class C I did some research into tire profiles versus other considerations.

I wanted more ground clearance anyway - but not too much more so that the DW could still easily get into the cab - without having to go to the 235/75 tires because I feared that the duallies might wind up too close together using the stock rims. So what I got by changing to the 215 tires from the 225 tires was the same load carrying capacity, greater dually tire spacings for improved inter-tire cooling, and no sidewall rubbing .... and my ultimate goal of a little more ground clearance for all of the chassis components without at the same time having to lift the coach higher up off the frame.

Admittedly I'm NOT a "tire designer" by any stretch of the imagination, but in my ignorance I don't buy into the current trend of huge rims with low profile tires on them. (Most) Big rigs still use high profile tires - just tires with a lot of plies and a lot of pressure to carry the weight. I think I want a "larger air chamber" between the road surface and the steel of the rims so as to provide a bigger/better air cushioned ride, while at the same time not sacrificing load carrying capacity - just as big rigs don't sacrifice load carrying capacity when sticking with high profile tires. To me it seems like todays low profile and wide footprint tires A), are a style thing coming from the racing world where vehicle tire sidewall flex needs to be non-existent under extreme side-forces and B), inherently make for an unnecessarily stiff ride resulting from a minimum size air chamber. I've ridden in plenty of todays fancy tired SUVs and sedans - and the ride is atrocious for various reasons - but IMHO at least partly due to the low profile tires on them.

On our Class C, what I would prefer is to be able to stay with 16 inch steel rims, but be able to get the additional ply rating from load range G tires on them, and also be able to get them in 215 size for better ground clearance. The higher ply rating would make for a more rugged/thicker tire material so as to better guard against punctures from sharp surfaces - such as curbs and rocks.

BTW, the 215 tire puts a narrower treadprint down on the road than a 225 tire ... which for the same load puts more pounds per square inch pressure onto the road surface. This increased pounds per square inch pressure probably makes for better snow and ice traction (... but worse flotation on soft surfaces).

brlowe wrote:
I looked at the 235/85 tires before and they were slightly wider and there were reports of them touching each other under load...
...normal E rated tire and put it up front keeping the duallys matched.

Yeppers, I wouldn't do 235/85 without a lot of investigation. And I'm glad you understand keeping the dual tires matched. FWIW, I believe the Right Rear Inner leads the toughest life of all six tires. Assuming of course we don't run them into curbs and stuff! Right Rear Inner carries a little more load than the Outers, and so does the Left Rear Inner. Differences are: First, we "occasionally" run Right Rear OUTER off the edge of the pavement. When we do that, the INNER gets shock loaded into the full weight of the right side of the rear axle. Second, at least on the Fords, it's right next to the hot tailpipe.
We have those Wonderful BORG Dually Valves so it's hard to do a full tire rotation. I've rotated Spare to Left Front, Left Front to Right Front, Right Front to Spare just to get use out of Spare as it ages. Thinking of what I just wrote, think I'll rotate the Rears after all. Take both Rights as a Set and rotate to Lefts as a Set.