really depends on the "type" of dirt... if it's very loose, the 4-snows, etc. work well, they are very light, & will round up like a wrinkle slick on a drag car, offering you the bottom end gear ratio of a 22" tire, & the top speed ratio of a 24"-26" tire, but they are only made for 8", 9", & 10" wheels
but I've found that for medium to hard surfaces, the paddles don't work as well as a tire with alot of biting edges... I like my 22" X 11" X 9" GBC Schredders, or one of the newer radial tread patterns for 12" wheels...
which ever you choose, keep your tire & wheel combo as light as possible...for 250ft - 300 ft distances a shorter tire will give you faster times, but if you are wanting to run in 4 X 4, it can take some special set ups to run less than 12" diameter wheels on the front of most moderned disk brake utility quads... you can pull the front brake calipers, to run shorter wheels needed for the specialty tires, or you can use a tire like the 489's that are offered in a 23" tire for a 12" wheel
BTW... you might find that spinning for the 1st 50 ft gives you faster times that too good a hook, & letting off the gas, to control a wheelie
post edited by Mike Walker - 2007/06/25 06:23:15