goufgators wrote:
zigzagrv wrote:
A couple questions: what is the length of your motorhome and chassis and what are your tire pressures?
32', rear 85, front 90
Sunstar rigs are all built on a 18,000 GVWR chassis with a front axle rated at 7000 lbs and a rear at 12,000 lbs. No idea why the GVWR is derated by 1000 lbs. The tires size will be 245/70R 19.5.
Front axle pressures are way too high for the axle and can cause straight line handling problems. At that pressure you have a load capacity in the tires of 7780 pounds. Dropping to 80 PSI cold, the low limit of Goodyears chart, which still gives you a tire load capacity of 7280 pounds, 280 beyond the axle limit.
Same for the rear. 85 psi = 14060 capacity with a 12,000 pound axle. Drop to 80 psi cold also which will give you 13,666 pounds. Lot a wiggle room with tire capacity if weights getaway from you. I suspect you'll find the coach will be a lot easier to drive.
Goodyear Inflation Tables (PDF)
