Determining the Correct Weight Capacity Tires For a 2018 Keystone Carbon 364 5TH Wheel Toy Hauler

Question:

Hello, Im the proud new owner of a 2018 carbon 364. After hearing all the horror stories about tire blowouts, Im very concerned that we may not have the correct ones on our rig. Currently on are ST235/80R16 F. The GVWR is 17000, GAWR 7000. The tires say the dual max load is 3305# so if I understand correctly, that means we can only carry 13,220#. Am I correct? And what do we need? Thanks in advance

asked by: Pat H

Expert Reply:

When looking at a tire like the Westlake ST235/80R16 Radial Trailer Tire # WE76FR on your 2018 Keystone Carbon 364 there are 2 weight ratings. The dual which you found is used when the tire is used in a dually setup(2 wheels and tires per hub). This Westlake for instance is a load range G and the dual weight is only 3,640lbs per tire. Since your Carbon is a single wheel per hub this tire would have a weight capacity of 4,080lbs per tire. You will want to verify the exact weight capacity of your tire on the sidewall. So for the Westlake with 4 tires would be 16,320lbs. The axles on your Carbon are rated for 7,000lbs each so as long as your tires are rated at least 3,500lbs each the tires are within the manufacturer specification for its components. Your GVWR of 17,000lbs is allowing 14,000lbs for the axles and 3,000lbs of tongue weight. The biggest issue being with a toy hauler if all the weight is in the garage it lifts weight off the front and could exceed the weight capacity for the tires and axles while still being within the GVWR of the trailer.

Based on your trailers weight ratings you could go down to a load range E tire like the Karrier ST235/80R16 Radial Trailer Tire # AM10248 as it is rated for 3,500lbs.

expert reply by: Bud M