Tire replacement questions?
 

I recently bought a 2011 Holiday Rambler Neptune and need to replace the tires. The current tires are GoodYear 670 size 275 80r 22.5. Can these be replaced with Toyo 275 75r 22.5 tires? Since the Toyos are a little wider, will there be enough clearence between the rear dual tires? Thanks for any information.

Doubt there’s much difference. The Michelin’s have thinner sidewalls and bulge more than a tire with thicker sidewalls. How much clearance do you have now?

If they are both 275mm, they should be the same width. The 75 series will be less circumference is the difference. That will make your speedo read a few percent higher than your actual speed. There should be no clearance issues, since you are going with a slightly smaller tire.

update
 

I should have said the toyos are 295 80R 22.5

Question, Toyo M154 tires that I have 6 of state to inflate to 120 lbs. On a hot July day, I had the shop near ne set the pressures to 115 LB. Today when the temp was 70 at max the tires increased to 126 lbs.

Is the sidewall tire pressure info based on the pressure at the start of the trip or after tires are driven a few hundred miles? And what about an adjustment for higher or lower ambient air temps?

I am satisfied wit these tires and just want to do my part on proper maintenance.

Tire pressures are the COLD inflation pressures - whether the number comes from the sidewall or an inflation table. I always go with the sidewall max, and have never had an issue with the ride at that number.

When a tire has been driven on for a while, it is considered "hot" and yes, the pressure will go up. A 20% increase in pressure from the temperature is not unheard of, especially on hot summer roads. If the running temperature was too high (I prefer to keep them below 150 degrees) that is when the glues start to give out. Sounds like yours are just at normal operating - IF they aren't overloaded. Do you know the axle weights for your coach and the ratings / sizes of your tires?

Nobaloney, you might want to change your name to just baloney. :D Welcome to the forums.
Your Neptune doesn’t need a 295 that’s used on tag axle rig.

Bpperk. ^^^^ “ Toyo M154 tires that I have 6 of state to inflate to 120 lbs”...sounds like they are on the back of your Signature that only needs 115 psi on the front axle. Your drive probably needs 95 and the tag only 80. You need to weigh your rig and then use the psi from the load tables pressures when cold.

Re the clearance issue. The 295-80s will be larger than your OEM 275-80s. Check dimensions and be sure.

I'd also be concerned with the steer tires clearing the wheel wells.

I decided to upsize for increased load capacity on my Diplomat, I originally had 275/75 R22.5 and went to 295/75. The most common size in trucking is 11R22.5 which is the same size as the 295/80 - but those are close to 2 inches taller than the 275! What I ended up with are called "low profile" b/c the sidewall isn't as tall as an 80.

Clearance on my drives was fine, but the steer axle where I wanted the extra capacity, the forward airbag perch was RIGHT AT the apex of the tire's turning radius. I was able to be a bit "creative" and shaved the base of the perch, so that the tire doesn't scuff the corner on the perch when making a tight turn anymore. There's no way I would be able to fit 295/80 under mine (or anything wider) unless the airbags were repositioned entirely.

Now for yours... You have to rotate the wheel while at ride height and as it turns from full lock to lock, see what kind of obstacles might be in the way. I'd be willing to bet there's something there that could cause issues, hopefully it can be moved or trimmed.

Why do you want to go to larger tire ? We recently replaced our 275 75 r 22.5 on our Diplomat with the same size. We are members of Family Motor and used their program> We chose Continental but Hankook and Michelin were available. We've run Toyo on our coaches before but we chose to go with the Manufacture original design.

I would suggest you look at the load tables and weight your coach. I had serious questions about the dimensions of sizes other than the original properly fitting the coach.

I would prefer to use the original size tires 275 80R 22.5, but there does not seem to be many available in that size except for very expensive Michelins. That is the only reason that I am looking at the 295 75R 22.5 Toyos.

What width rims do you have?

If they are 8 1/4", you shouldn't have any issues on the drive axle.

Clearance from your spring mounts on the front could be an issue though.

Check out the FMCA tire discount program. Many times it will save you much more than the cost of membership.

https://fmca.com/rv-tires-discounts