I own a 2011 Jayco Greyhawk 31 FK. Before we left for Alaska I purchased a used rim and a tire. It came off a 450 chassie and wieght rating was right. I ended up with $75.00 in it but I had a good spare. We made the 12,000 mile round trip and luckly did not need it. We put it in the rear storage area and just packed around it. We carried supplies for 65 days and had plenty of space.