Credit is definately tighter for RVs than it is for other types of standard loans (car/house) because they are considered 'luxury' items. Ie, if you have a loss of job or other major life change that leaves you unable to pay your bills, most folks will stop paying on the RV before a car or home.
If you have really good credit (700+) you can get some pretty good rates. However, many lenders look at the LOWER of the two credit scores, or average them together. That may be why you are being quoted such a higher interest rate.
A couple years ago when buying our first TT, we talked a lot with the finance guy at the dealer ship about how RV loans worked. He told us that at that time he wasn't able to get financing at all if any of the co-signers had a credit score was 650 or lower. When we did our new TT purchase last year he told us that it's a bit looser now, but still a lot of scrutiny.
It also depends on what area of the country you are as to what rate you will be quoted.
Check with your credit union - ours has a standard 7.5% on all RV loans, BUT they don't look at your credit score, and will do smaller loans. They do require 25% down on the smaller end loans. The advantage is that they only look at your over all income to debt ratio AND your actual credit report to make sure you don't have any late payments, foreclosures, etc.
It is true the larger the loan, usually the longer terms and lower rate you may be able to get with a lot of traditional lenders.
It definately doesn't hurt to shop around on your own and not just go with whatever the dealer comes up with first. There are a lot of options out there! Good luck!
2012 Flagstaff V-lite 30 WTBS
2011 Ford Expedition
4 kids and a hubby & never enough time to camp!
2011: 17 nights 2012: 26 nights 2013: 46 2014: 20 2015: 16