For a PDF of the redlined version of the previous version of the Max 4 rules, click here

1. Max 4 eligible vehicles include production vehicles of more than 1,000 examples and eligible kit cars powered by the following OE engine displacement or KW-rated motor(s) and not weighing less than the corresponding minimum weight (with driver):

A. Unmodified naturally aspirated 4-cycle engines between 3.7x and 4.5L OE measured displacement: 3000lbs.

B. Unmodified naturally aspirated 4-cycle engines between 3.0x and 3.7L OE measured displacement: 2700lbs.

C. Modified naturally aspirated rotary or 2-cycle engines of up to 1.5L OE measured displacement: 2700lbs.

D. Modified naturally aspirated 4-cycle between 1.9x and 2.9L OE measured displacement: 2700lbs.

E. Unmodified single-unit forced induction 4-cylinder, 4-cycle engines between 1.9x and 2.46L OE measured displacement: 3000lbs.

F.  Unmodified single-unit forced induction 3-cylinder, 4-cycle engines between 1.5x and 1.9L OE measured displacement: 3000lbs.

G. Electric vehicles with unmodified OE batteries and up to 250 KW of OE rated motor(s): 2800lbs.

H. Electric vehicles with modified/replaced batteries or modified motor(s) up to 175 KW OE rated motor(s) limit: 2800lbs.

2.All Max 4 eligible cars underweight by up to 300lbs go to Max 2.