Whats the difference between a 33x12.5 and a 285x70 ?? Is there really any noticeable difference?? Whats bigger ?

 

http://www.onlineconversion.com/tire...conversion.htm

Imperial (inches) vs Metric (millimeters).

To compare the sizes you need the rim size as well. 285x70R17 = 285mm tire width, 70% of the width is the tire profile, 17" rims.

 

x2 on conversion, but also dep on rime size, 16-17 it will be around 31-32

 

Width: A 285/70R17 is noticeably narrower than a 33x12.5x17. 285 mm = 11.2 inches, so it's about 1.3 inches narrower (if the tires' dimensions are exactly accurate, which they rarely are).

Height: It depends on the manufacturer. Brand X's nominal 33 may actually measure 32.5", and Brand Y's nominal 33 might be 33.1". A 33x12.5x17 and a 285/70R17 should be about the same height, give or take a couple tenths of an inch.

With a 33x12.5x17 you have to use wheel spacers or aftermarket wheels with less backspacking. You can use your stock wheels and no spacers with a 285/70R17.

Typically wider tires are heavier and cause more rolling resistance than narrower tires. I think I would go with the narrower tire because it might be a little better on gas (maybe 1 mpg).