Originally Posted by flyncasafo
I currently have 205/75R15 tires with a load rating of C or 1820lbs. The goodyear replacements are 225/75R15 with a load rating of D or 2150lbs. I do not know how wide my rims are but would I need a larger rim for the 225s?
Are your proposed replacement tires ST (Special Trailer)? If not, they really should be. ST tires are specially made for trailering. They have stronger sidewalls and other features that make them much more suitable for trailering. Regular passenger car tires are not supposed to be used on our trailers.
ST205/75R15's are still commonly and widely available from many manufacturers including Goodyear. It is basically an industry standard size for the trailering market. (I know because I have one sitting in my truck waiting to be replaced. It got wacked in the sidewall and is now useless. It's off my son's boat trailer, not my Sunline.)
To answer your original question, the ST205/75R15's need a rim width of 5" to 6.5". The ST225/75R15's need a rim width of 6" to 7". So, if your existing rims are at least 6" wide, you can upgrade to the larger tire without buying new rims.
I found a really nice tire size chart for the Goodyear Marathon Radial trailer tires at: Click Here.
Goodyear's chart for the Marathon radials is here.
'12 F250 4x4 Super Duty PowerStroke 6.7 diesel
2011 to present: '11 Cougar 326MKS
1999 to 2011: '99 Sunline T-2453
Amateur Radio kd2iat monitoring 146.52