i have heard dot3 brake fluid has been around for like 40 years and dot4 is newer and withstand higher temp but i saw a synthetic brake fluid made by castrol and it claims that it is exceed dot3 and dot4 quality. i am just wondering what type of brake fluid does everyone use? thanks

 

use what your car calls for. I used DOT-4 in all my cars and had no problems. Make sure to never use DOT-5.