Tire sizes

[John Shaw]

I have a 2012 Keystone Montana 3400RL. It's time again to change tires. Can I safely change from Goodyear Marathon ST 235/80R 16 E to Michelin LTX M/S2 LT 235/85 R 16 E 120/116R

[bobbecky]

NO!! Your rig weighs less than 200 lbs less than our rig, and if you are replacing tires, you need to go at least the same as you had, and if you want to reduce the risk of problems with blow outs, you would be better off going to an F or G rated tire. The ST tires your rig came with were rated 3420 lbs capacity, and the E rated LT tires are rated 3042 lbs capacity. On your trailer's tag, you will see the 7,000 lb axles were derated to 6750 lbs, so the E rated ST tires it was shipped with were legal. I replaced our tires with the Goodyear G614, but Sailun has the S637 tires that have been working well for most people at a much lower price, and they are both G rated tires, that will work with your wheels. The G614 tires were offered as an option in 2012, and they were mounted on the same wheels as on your rig, just have to upgrade the stems to ones rated to handle the 110 psi that the tires can use.

[John Shaw]

Thank you. I don't know whether to go with the Goodyear G614's or the Sailun S637.

I had the Goodyear Marathon ST235/80R16E that came on the trailer. Thought the Michelin would be the same. With the Marathon's I had one go out of round and another blow out. I have the tire minder system on the trailer. just want peace of mind. I usually cruise no faster than 60 mph and still had the above problems.

[bitten]

Sailun ordered for my rig.

[sourdough]

Thank you. I don't know whether to go with the Goodyear G614's or the Sailun S637.

I had the Goodyear Marathon ST235/80R16E that came on the trailer. Thought the Michelin would be the same. With the Marathon's I had one go out of round and another blow out. I have the tire minder system on the trailer. just want peace of mind. I usually cruise no faster than 60 mph and still had the above problems.


Go to the NHTSA website and look at the problems with the Goodyear Marathon. They are no longer the tire they were many years ago.

[bsmith0404]

As already mentioned the LT tires are only rated at 3042. That gives you just over 12k lb capacity on the 4 tires. You probably have pretty close to that on the wheels. In theory, you have enough load capacity if there is equal weight at each tire. The problem, RVs are not built with a perfect balance on all 4 corners. You will most likely exceed the weight rating of at least 1 tire. Also, you have no room to spare for tire degradation. Definitely look into an F or G rated tire.

There are some on here that swear by LT tires, others who swear by ST. Personally I like the ST tire.