Originally Posted by SeaDog
couple of things besides weight to consider when thinking about the rating of your tires. I have "C" now and will be changing to "E". The speed you drive, ST tires have a 65 mph limit (I don't exceed this). Where you camp, I need the E rated tires (for the ply rating) because of backroad Idaho camping. It is very easy to put a rock thru the tread or sidewall.
Not sure where you got your information Seadog but there isn't a tire that is meant for the highway that is rated for less that 75mph. S rated is 112mph. You may not want to tow anything faster than you can do so and handle/react in a safe manner but it is not the tires that are holding you back unless you are exceeding the weight index rating they were made for.
L 75 mph 120 km/h Off-Road & Light Truck Tires
M 81 mph 130 km/h Temporary Spare Tires
N 87 mph 140km/h
P 93 mph 150 km/h
Q 99 mph 160 km/h Studless & Studdable Winter Tires
R 106 mph 170 km/h H.D. Light Truck Tires
S 112 mph 180 km/h Family Sedans & Vans
T 118 mph 190 km/h Family Sedans & Vans
U 124 mph 200 km/h
H 130 mph 210 km/h Sport Sedans & Coupes
V 149 mph 240 km/h Sport Sedans, Coupes & Sports Cars