Switching From ST5.30-12 Load Range D Tires To ST145R12 Load Range E Tires On Jayco Camper

Updated 10/04/2012 | Published 10/02/2012

Question:

I have a Jayco 860 pop-up camper with ST5.30-12 Load Range D tires. The axle is rated at 2200 lbs. and the trailer weighs about 2000 lbs. We do a lot a 60-65 mph driving on Interstates, mainly in the Summer, and the tires run awfully hot. Brakes are carefully adjusted to avoid dragging. The trailer rides and tracks very well. I was thinking of switching to the ST145R-12 tires sold by you. Even though a Load Range D has ample capacity relative to the axle rating, would it be better to go with Load Range E? Two questions: 1 Would the ST145s run cooler than the 5.30s? 2 If so, would the ST145 Es be a better choice than the Dsinch to keep things cooler even though the extra load capacity isnt needed?

asked by: Don K

Expert Reply:

I would recommend switching from the ST5.30-12 tire size to the ST145R12 size because the advantages of going to a radial design tire. Because of the construction of a radial tire, the tire has more flex and will allow for more ground contact. That will improve traction and better tread wear. It also gives the radial tire better stability.

The radial tire will normally run cooler, if not overloaded, which will help the tire last longer, especially when the tire is under a load.

You will also want to make sure to run the maximum air pressure that is stamped on the sidewall of the tire to help reduce the heat buildup inside the tire. If you put a load on the tire and the tire pressure is lower than specified it will cause the tire to heat up quicker.

As far as comparing the load range D to the load range E, the load range E might run a little cooler compared to the load range D when hauling a heavier load, but I do not think the difference would be that significant. The load range E tire will not give your trailer anymore weight capacity because the weight capacity will still be limited by the 2,200-lb axle or the lowest weight capacity in your trailers suspension.

I am including a link to a FAQ page on trailer tires.

expert reply by: Jeff D