Originally Posted by
autumnmass
Confused, is DOT 4 the same as DOT 4+?
Originally Posted by ;
supposedly the only difference is the heat tolerance..ive got 13'' rotors and 6-pot calipers on all 4's and use DOT4...works fine considering i am not halting from 150 mph to 0 daily..
Below is a side by side of the two compaired.
(% of moisture/boiling point)
DOT 4 DOT 4+
1% 446F 1% 527F
2% 383F 2% 428F
3% 347F 3% 383F
4% 320F 4% 365F
Found this on another site... and a few more tidbits..
In so many words, DOT 5.1 fluids are simply DOT 4-type fluids which meet DOT 5 performance requirements. Because of this, they typically can be mixed with DOT 3 or DOT 4 fluids without concern. In some circles, they are even referred to as ‘DOT 4 Plus’ or ‘Super DOT 4’ fluids because they are more similar to a conventional DOT 4 fluid by chemistry than they are to a conventional DOT 5 fluid.
While it may not be obvious, the big advantage of the DOT 5.1 fluids is that they contain all of the nifty water-absorbing characteristics of the DOT 3 and DOT 4 fluids while simultaneously providing for very high boiling points and relatively stable viscosity over a wide range of temperatures.