DO NOT use DOT 3 fluid, only DOT 4 is acceptable. It says both in the owners manual and on the brake resevoir that DOT 4 is the only fluid for our brake systems because it is better at higher temperatures and is less suseptable to brake fade. Now, if you have a car that takes only DOT 3 fluid, it is OK to put in DOT 4 fluid because it is just better; in other words you can upgrade but you don't want to use a lesser grade than they tell you. And, no matter if the car says DOT 3 or DOT 4, NEVER EVER use DOT 5 fluid because it contains silicone and will destroy the seals of the system.