Different Tire Sizes Front to Back

[2Ropes]

Looked at a 2007 Tiffin Bus recently and the vehicle placard calls out 275/80R 22.5 tires front and back but this coach had 295/80R on the front. Any good reason for this or any issues with this as harm to the coach?

[alank]

That difference won’t hurt a thing as long as clearances around the fender well and steering components are adequate.

The owner may have found a good deal on the tires, may have been near the weight limit on original tires or just wanted a little less pressure for a softer ride.

[Skip426]

As mentioned by alank , a PO may have had a reason for the change ; but ; the tire's RPM ( Revolutions Per Mile in tire talk ) would need to be looked into , as too much difference front/rear could effect anti-lock brake function.

[NXR]

Good thought, Skip426. Tire size comparison attached.

The OP did not say exactly which tires they were so I looked up the Michelin load inflation charts. Surprisingly, the 295 actually could have a lower load limit than the 275 but it depends on exactly which tires they are. The 275 comes in both a "G" and an "H" load range as well.

2Ropes, there is a sticker that lists the factory tire size and load range. It's usually on the wall behind the driver, at least nowadays. What does that sticker show for the factory front and rear tire sizes and load range?

Ray

[RVFunlovers]

The vehicle info sticker (normally behind or near driver seat area) will tell you what size tires came on the coach.

My last two coaches have had larger tires in the front.

I would use the tire size the manufacture calls for unless I had a good reason not to.

[2Ropes]

Originally Posted by NXR

Good thought, Skip426. Tire size comparison attached.

The OP did not say exactly which tires they were so I looked up the Michelin load inflation charts. Surprisingly, the 295 actually could have a lower load limit than the 275 but it depends on exactly which tires they are. The 275 comes in both a "G" and an "H" load range as well.

2Ropes, there is a sticker that lists the factory tire size and load range. It's usually on the wall behind the driver, at least nowadays. What does that sticker show for the factory front and rear tire sizes and load range?

Ray

The sticker indicates 275/80R22.5 front and rear. Doesn't give load rating of tire but the front GAWR is 14,320 and rear is 20,000

[NXR]

Originally Posted by 2Ropes

The sticker indicates 275/80R22.5 front and rear. Doesn't give load rating of tire but the front GAWR is 14,320 and rear is 20,000

Michelin load chart image attached in case it helps. The tire sticker usually indicates the load range letter.

Ray

[NXR]

But...the attached pic from the Michelin RV Tire Guide shows the alternate tire size for the 275/80R22.5 is the 295/75R22.5, not 295/80R22.5 as you wrote.

Are you certain about that front tire size?

Ray

[96 Wideglide]

Originally Posted by 2Ropes

The sticker indicates 275/80R22.5 front and rear. Doesn't give load rating of tire but the front GAWR is 14,320 and rear is 20,000

My front axle is rated at 14,640lbs, and the coach leaves the factory with 295/80R22.5's

[Gary RVRoamer]

First of all, let's be clear that there is nothing inherently wrong with having different size tires on different axles. In fact, it's a fairly common thing for some models. However, changing the OEM size requires that the owner/installer verify that the new tire size does not impact anything. For example:

• Make sure the tire load rating is sufficient for the axle GAWR
• Determine that the tire width and diameter fit within the wheel well at a maximum turn angle
• If the vehicle has ABS, make sure the tire revolutions per mile are within the range the ABS wheel speed sensors can handle. Note that an ABS system may not have wheel sensors on the front axle
• For dually axles, make sure the dual spacing is adequate.