biggest tire size?

[vx1999]

Try this tire size calculator to compare what you have to alternatives:

http://www.discounttire.com/dtcs/infoTireMath.do

[Mile High VX]

Try this tire size calculator to compare what you have to alternatives:

http://www.discounttire.com/dtcs/infoTireMath.do

Remember that if you're using aftermarket rims with a different offset than the +38 OEM this is good for speedometer variance but won't tell the whole story on what cladding trim might be needed...