PRO STOCK TRACTOR: Originates from 1/16 scale 2 wheel drive tractor
WEIGHT CLASSES: 3lb. & 5lb.
MAX. WHEELBASE: 8"
LENGTH LIMIT (Center of rear axle forward): 10 1/2"
MAX. NUMBER ENGINES: 1
MAX. ENGINE DISPLACEMENT (Cubic inches): .061
NO THROTTLE CABLE ALLOWED
TIRE DESIGN: Black rubber only 35 durometer or higher
MAX. TIRE SIZE: 1 5/8" x 4 1/4"
MAX. HITCH HEIGHT: 1 1/4"
MIN. HITCH LENGTH (Center of rear axle to back of hitch hole): 1 1/8"

TWO WHEEL DRIVE: Replicates 2 wheel drive road vehicle
 MAX. WEIGHT: 4lbs.
 MAX. WHEELBASE: NO LIMIT
 LENGTH LIMIT (center of rear axle to front of vehicle): 12"
 MAX. NUMBER OF ENGINES: 1
 MAX. ENGINE DISPLACEMENT(cubic inches): NO LIMIT
 THROTTLE CABLE ALLOWED
 TIRE DESIGN: OPEN
 MAX. TIRE SIZE: 2 1/2" x 3 1/2"
 MAX. HITCH HEIGHT: 1 1/4"
 MIN. HITCH LENGTH(center of rear axle to back of hitch hole) 1 1/8"
 MAX. GEAR RATIO: 300:1


SUPER STOCK TRACTOR: Originates from 1/16 scale 2 wheel drive tractor
MAX. WEIGHT: 5lbs.
MAX. WHEELBASE: 8"
LENGTH LIMIT (center of rear axle to front of vehicle): 10 1/2"
MAX. NUMBER OF ENGINES: 1
MAX. ENGINE DISPLACEMENT (cubic inches) :   .15
 THROTTLE CABLE ALLOWED
TIRE DESIGN: OPEN
MAX. TIRE SIZE: 3"x5"
MAX. HITCH HEIGHT: 1 1/4"
MIN. HITCH LENGTH (center of rear axle to back of hitch hole): 1 1/8"

FOUR WHEEL DRIVE: Replicates 4 wheel drive road vehicle
MAX.WEIGHT: 6lbs.
MAX. WHEELBASE: 8 5/8"
LENGTH LIMIT (center of rear axle to front of vehicle) : 13"
OVERALL LENGTH: 16"
MAX. NUMBER OF ENGINES: 1
MAX. ENGINE DISPLACEMENT (cubic inches) : .15
THROTTLE CABLE ALLOWED
TIRE DESIGN: OPEN
MAX. TIRE SIZE: 1 1/2" x 3"
MAX. HITCH HEIGHT: 1 1/4"
MIN. HITCH LENGTH (center of rear axle to back of hitch hole) : 2 1/2"
FRONT TIRES MUST BE CENTERED IN WHEEL WELLS

OPEN MODIFIED "HOT ROD" TRACTOR
MAX. WEIGHT: 6lbs.
MAX. WHEELBASE: NO LIMIT
LENGTH LIMIT: 18"
MAX. NUMBER OF ENGINES: NO LIMIT
MAX. ENGINE DISPLACEMENT: NO LIMIT
THROTTLE CABLE ALLOWED
TIRE DESIGN: OPEN
MAX. TIRE SIZE: WIDTH OPEN x 6" DIAMETER
MAX. HITCH HEIGHT: 1 1/4"
MIN. HITCH LENGTH (center of rear axle to back of hitch hole) : 1 1/8"

SEMI "BIG RIG"
MAX. WEIGHT: 7lbs.
RECOGNIZABLE TRUCK BODY
LENGTH LIMIT: 18"
MAX. NUMBER OF ENGINES: ONE
MAX. ENGINE DISPLACEMENT: NO LIMIT
ENGINE MUST STAY INSIDE THE BODY, ONLY THE EXHAUST OR CYL HEAD MAY BE OUTSIDE THE BODY
THROTTLE CABLE ALLOWED
TIRE DESIGN: OPEN
MAX. TIRE SIZE: WIDTH 3" x 3" DIAMETER if running singles, 1 1/2" x 3" if running duals
TANDEM DRIVE AXLES ARE ALLOWED, MAX DISTANCE BETWEEN DRIVE AXLES 4 1/4"
MAX. HITCH HEIGHT: 1 1/4"
MIN. HITCH LENGTH (center of rear axle to back of hitch hole) : 1 1/8"