Skip to main content ↑ ↓
Topic: Tire size?????? (Read 1359 times) previous topic - next topic

Tire size??????

I would like to hear from the experts please.
I currently have Bridgestone 295/75R 22.5 tires. The plate next to the steering wheel from FT calls for 295/80R 22.5. As I understand from a quick Google search, the 80's are slightly taller (1.16"). Which way to go with new tires? Also prices and brands? I will be comparing with what I can purchase through my employer. They buy $1m + every year, so they say they get a great discount.

Thanks for the input in advance,
Larry
Larry Warren
1996  U320 36' SBID "Lola" sold 2020
Build #4970
Motorcade #18318

Re: Tire size??????

Reply #1 –
Larry,

Please re-read your plate.  Based on 1996 U320, no slide coach, I think you will find the plate says 275 80R 22.5 vs 295 80R 22.5.

The 295 80R is a taller tire that carries more weight than a 295 75R.

The 275 80R and 295 75R tires are less than 0.1 inch different in diameter.

Hope this helps.
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: Tire size??????

Reply #2 –
As Rudy indicates 275/80 and 295/75 are very close in diameter.  The only thing to watch for with the plus one size is the width in the wheel wells, tire to tire on drive axle, and avoiding contact on components at max steering angle on steer axle.

I think few (if anyone) has had issues with the plus one 295/75.

I run plus one size on my tow car.  (basically same diameter, slightly wider). Better availability of tire choices.
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: Tire size??????

Reply #3 –
Thanks, I will check again. I took a picture of the plate, but it didn't show up well (should have checked before leaving the coach.)
Larry
Larry Warren
1996  U320 36' SBID "Lola" sold 2020
Build #4970
Motorcade #18318

Re: Tire size??????

Reply #4 –
If your coach has been weighed on all four corners, you might be able to run at lower pressures with different tires. I was able to come down 20 psi from original. That equals better ride!  ^.^d
1993 U-240 "La Villa Grande"..CAT 3116 w/ Pacbrake PRXB...Allison 3060 6-speed..
Previous: 1983 Airstream 310 turbo diesel, 1979 Airstream 280 turbo diesel
                                      Build # 4297
                                      PNW natives
                      Home base:  'Cactus Hug' (Ajo, Arizona)
                        DW Judy & Chet the wonder dog
                        Full-Timers 'Sailing the asphalt sea'

Re: Tire size??????

Reply #5 –
Ok, I have now verified that I am not totally insane, (still open for debate). I drove the 40 mile round trip in freezing rain to check. On the plate next to the steering wheel, the manufacturer calls for 275/80R 22.5 tires. The tires on the rig are Bridgestone 295/75R 22.5. Again I ask what is the difference? These tires have been on here for around 10 years as near as I can calculate. (Previous owner 8 yrs, me 2 yrs.)

Thanks,
Larry
Larry Warren
1996  U320 36' SBID "Lola" sold 2020
Build #4970
Motorcade #18318

Re: Tire size??????

Reply #6 –
Quote from: ohsonew –
Ok, I have now verified that I am not totally insane, (still open for debate). I drove the 40 mile round trip in freezing rain to check. On the plate next to the steering wheel, the manufacturer calls for 275/80R 22.5 tires. The tires on the rig are Bridgestone 295/75R 22.5. Again I ask what is the difference? These tires have been on here for around 10 years as near as I can calculate. (Previous owner 8 yrs, me 2 yrs.)

Thanks,
Larry


First post above: "The plate next to the steering wheel from FT calls for 295/80R 22.5."  Now you correctly identify the OEM tire size as 275/80/22.5. 

275/80/22.5  and 295/75/22.5 are commonly interchaged sizes.  The upgraded size of 295/75 is commonly called a plus one size.  The 295 is a bit wider than 275 (but accepable in most applications), the 75 compensates for the height" or diameter of  larger tire than the stock size.

Said another way the 295 on your coach is slightly wider, but the height or diameter is fine. Many people use the 295/75 instead of the 275/80. either is acceptable in most applications.

More concerning is the date of your tires. I would change them ASAP. Google "DOT date code".



Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: Tire size??????

Reply #7 –
We contacted Michelin when looking for PSI specs on our fresh 255/80R 22.5 tires, load range "G", our coach had been weighed.  If you know your coach weight on all four corners (with 50% liquids) ,any decent tire outlet can tell you the load range & psi for the brand you're looking for.  ^.^d  BTW, our tires were at 100 psi when we bought her, and she rode hard!
1993 U-240 "La Villa Grande"..CAT 3116 w/ Pacbrake PRXB...Allison 3060 6-speed..
Previous: 1983 Airstream 310 turbo diesel, 1979 Airstream 280 turbo diesel
                                      Build # 4297
                                      PNW natives
                      Home base:  'Cactus Hug' (Ajo, Arizona)
                        DW Judy & Chet the wonder dog
                        Full-Timers 'Sailing the asphalt sea'

Re: Tire size??????

Reply #8 –
Dan, I agree on the age of the tires. That's why I'm asking the questions. Planning on new tires asap. The coach has been stored for  the last 1 1/2 yrs with the exception to exercise it. Hoping to get to use her this year. In checking my notes from the first post, I did misrepresent the OEM plate numbers. I got my wires crossed when typing the post.

Mike, my Bridgestone's have been maintained at 100 psi since I have owned it. The ride was comfortable for us. Lighter air pressure would make it even softer, but will have to play with it to see.

Thanks,
Larry
Larry Warren
1996  U320 36' SBID "Lola" sold 2020
Build #4970
Motorcade #18318

Re: Tire size??????

Reply #9 –
FYI;  I went to the  295 75R/22.5  several sets of tires ago. I have had no problems as far as tire rub or any over heating of the duals in the rear.  I feel I have gotten a better ride and steering from the slightly wider tires on the front of my coach.  I have also increased my tire weight grade from "G" to "H" just to give me a stronger side wall and weight carrying ability.  ^.^d  Hey Larry,  the number after the "R"  R/80  versus  R/75,  relates to the tire height and the 275 or 295 relates to the tire tread width........ 
The selected media item is not currently available.
Gerry & Brenda
CHARLOTTE HARBOR, FL
1994 Grand Villa - # 4466
U300 Unihome - 6V92 Detroit
4 speed Allison - Jake Brake

Re: Tire size??????

Reply #10 –
Thanks Gerry, I appreciate the help.

Larry
Larry Warren
1996  U320 36' SBID "Lola" sold 2020
Build #4970
Motorcade #18318

Re: Tire size??????

Reply #11 –
To determine when tire was manufactured look on the sidewall at the DOT Code.  First number is the week, second number the year.  Picture example, 13th week of 2009.
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: Tire size??????

Reply #12 –
Only one tire has the date code on the outside. It was enough to know that new rubber is in order all the way around.
Larry Warren
1996  U320 36' SBID "Lola" sold 2020
Build #4970
Motorcade #18318

Re: Tire size??????

Reply #13 –
Quote from: ohsonew –
Only one tire has the date code on the outside. It was enough to know that new rubber is in order all the way around.

Insist and inspect for a fresh date code. Podunk tire stores can have them sitting around forever and will also suggest a tire size/load range that they want to dump.  >:D
1993 U-240 "La Villa Grande"..CAT 3116 w/ Pacbrake PRXB...Allison 3060 6-speed..
Previous: 1983 Airstream 310 turbo diesel, 1979 Airstream 280 turbo diesel
                                      Build # 4297
                                      PNW natives
                      Home base:  'Cactus Hug' (Ajo, Arizona)
                        DW Judy & Chet the wonder dog
                        Full-Timers 'Sailing the asphalt sea'
 

Re: Tire size??????

Reply #14 –
I used a tape measure to determine the tread width of (275 80) and (295 75) tires and found they were both a little more than 9 inches, so the same width. I realize that not all tires (with the same numbers on them) but from different manufacturers are the same size. I wonder if some models of tires from the same manufacturer are the same size. For example, Toyo makes M-170, M-177, M-154 tires (and more) that are 195 75R 22.5. I wonder if the tread width is the same on all these tires.
Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada