Tires: RV Tire Size, Brand, Load Range, winnebago chieftain, gross axle weight

Question
-------------------------
Followup To
Question -
Maybe you can help me.  I have a Winnebago Chieftain 22, 1987.  I am second owner, it had Remington's 7.50R 16 load range D tires on it when I bought it 3 years ago.  The owner prior to me has put 21 tires on it since 1987…it has over 100,000 miles.  Since I have had it I have put 6 tires in the last 3 years…Remington's 7.50R 16 load range D.  It sits in my driveway and I drive it more than once a month, usually 500 miles a month.  It has been recommended that I need to change brands as well as load range.  The Remington's are separating…tread is separating with very little mileage on the tires……………..PLEASE HELP ME…CAN YOU GIVE ME ANY RECOMMENDATIONS…TIRE SIZE, BRAND, LOAD RANGE.

I would really appreciate it.

cheers...steveb
Answer -
Steveb,

Here's what I think is going on:

I think the tire is too small.  A 7.50R16 LR D has a maximum carrying capacity of 2470 # @ 65 psi.  I think you need a LR E in a similar size.

But let's start with the basics:

First find the vehicle certifictaion label, also know as the placard.  It has the tire info - size, and inflation pressure.  It also should have the GAWR's.  (Gross Axle Weight Ratings)

The placard is usually on a door post or in the glove box.

Then you should weigh the vehicle by axle (each corner would be better)  Be sure to load the vehicle up - full tanks everywhereand every poosible thing that would be carried, including people.  In other words, the worst case.

Now compare the GAWR's with the readings.  I'll bet you find the readings are over the GWAR's.  That mean Winnebago didn't size the tire correctly.

Next step would be to add at least 10% (15% would be better) to the weight readings.  Then divide by the number of tires.  You'll want a tire that has at least that capacity.

It turns out the old standby LT235/85R16 has about the same diameter and comes in a LR E - max load 3042 # single / 2778 # dual at 80 psi.

Hope this helps.

"I can't believe you answered so quickly"  Thanks for your response...Now, one more.  Will LT235/85R16 tires touch on my duals or are they the same with as the 7.50R16's?  If not, is there a spacer and is this the way to go?

cheers...steveb  

Answer
Steve,

I can't tell if this is the way to go without looking at the placard and weighing the vehicle.

But the duals require 1/2" more for the LT235/85R16's - 10 1/2 centerline to centerline.  So check the spacing and get a spacer if you need to.

Hope this helps.