Trailer Tire ST235/80R16 vs ST235/85R16 for 2012 Keystone Alpine 3500RE

Updated 06/17/2019 | Published 06/14/2019

Question:

2012 Keystone Alpine 3500RE came with the ST235/80R16 tires but you guys are recommending I upgrade to the ST235/85R16. Why not the ST235/80R16? Is there a difference in load rating? The 85’s will decrease the spacing between my tandem axle tires by an 1”. I saw in a previous post it is recommended to have at least 4” between tires.

asked by: Ben E

Expert Reply:

So the overall diameter difference between a ST235/80R16 tire size and a ST235/85R16 is .7 of an inch so that is how much clearance you'd lose between your current tires. If you have at least 4.7 inches there currently you'd be fine to go with the larger size.

In your previous question you mentioned having a trailer with a GVWR of 15,000 lbs which is why I recommended the larger size part # AM10501 since it has the capacity you'd need. The smaller size of ST235/80-16 would be a great choice if it's lower capacity would be adequate. It's capacity is 3,420 max load at 80 psi which in a tandem axle setup would have a total tire capacity of 13,680 lbs. If when your trailer is loaded it weighs less than that this would be a great option.

expert reply by: Jameson C