its important to have the right size tires because rubbing can create a lot of damage. Some people say not to get 305 because they rub a little. The best bet would be 305-40-22 or 285's.
You can not mix different size tires and rims. The tire has to be the same size as the rim.
It depends on the tire. It could be made for a 15, 16, 17, etc size rim.
No
That depends on the rim width and the vehicle it is installed on.
It all depends on the application.
That depends entirely on the application.
the R stands for RIM , Example R15 Is a 15 Inch Rim The R actually means it is a tire of Radial construction. The wheel & tire diameter is 15" but the width of the rim should be 7" to 8" for this size tire.
what is the largest tire I can put on a stock 20 inch 2008 dodge ram rim
No!. It is very unsafe to mix tire and rim sizes.
No, the R15 means that it is a radial tire and the 15 is the rim size. Never try to mount a tire and a rim that are different sizes.
A 15 inch tire from 185 - 225 mm
The basic rim size must always be 16 inch, however within limits you can change the width or aspect ratio.