Dot 3 and Dot 4 brake fluid. Whats the diff ?

[greenacc]

Anyone got any ideas ?
Also between the different Dot 4's on the shelf at repco etc, are they all the same or are some better ? Valvoline Performance Dot 4 for instance ..

[cpbait]

there all pritty much the same, dot 4 as far as i know is bassicly just a replacement for dot 3, should say on the back or in one of those castrol catalogues, bassicly its what there using in the new model cars.

main difference is the colour they come out in, some will be clear goldy type fluid colour and some will be a greeny colour, etc.

[danja]

I think it's something to do with the boiling point, and probably something about what it's make of so all the components don't corrode etc.

Google is still your friend:
DOT 4 - Wikipedia, the free encyclopedia

EDIT:
Use whatever the manual says and you'll be fine.