Hyundai: brake fluid, hydraulic clutches, hyundai accent

Question
I recently purchased a new 2004 Hyundai Accent. My owner's manual states that when I fill up my brake fluid I should use DOT 3 or DOT 4. I don't understand this. Is DOT 3 and DOT 4 the same fluid? If it is how come they have different numbers? Thank you for your response. Al Brown

Answer
Hello Al, it's just like any other fluid. Example the difference between WD-30 and WD-40 oil.  Both pretty much the same, however one is richer and thicker.  With Dot 3 and Dot 4 both are usually grouped together. Both are for ABS, hydraulic drum and disc braking systems and hydraulic clutches.  Some cars require a specified Dot 3 or Dot 4.  4 can hold up to a degree maximum of 500 degrees.  If your manual is stating either one, then either will do.  Thank You.