Racing brake fluids come in all different colors and temerature ratings. What is the best one for your application depends on several factors such as : How heavy the car is; How fast the car is?, What size are the brakes relative to the weight and speed of the car; How much air flow gets to the brakes; and last but not least, How much money you want to spend?
Let's see if we can sort this all out. Let's say you have a 3,000 lb. with 250 hp and relatively small brakes (i.e. stock) and you don't have additional brake ducting. Even if you are using the best racing brake pads made (i.e. Pagid) you still need to be using a racing brake fluid if you drive your car on the track. Most racing brake fluids are rated DOT 4 and they publish a Dry and a Wet Boiling Point for each fluid. The Dry boiling point is actually more of a theoretical or laboratory boiling point since all brake systems, even though they are sealed, have a certain amount of moisture in them. So the "Real World" number you should be looking at is the Wet boiling point. The following table will give you exactly what is available from the major manufacturers of racing brake fluid:
Ate Super Blue Racing (1 Ltr.) Dry-536F Wet-392F Cost-$15.00
Ate Typ 200 (1 Ltr.) Dry-536F Wet-392F Cost-$15.00
Motul RBF600 (1/2 Ltr.) Dry-594F Wet-421F Cost-$16.50
Motul RBF660 (1/2 Ltr.) Dry-617F Wet-399F Cost-$29.95
Castrol SRF (1 Ltr.) Dry-590F Wet-518F Cost-$79.95
What can we learn from this chart. The best value is clearly one of the ATE fluids. If your car is still under factory warranty and you are tracking your car and are trying to fly "under the radar" at your dealership you might want to consider ATE Typ 200 since it is amber (just like your o.e. brake fluid) rather than using Super Blue which is Navy Blue and will certainly tip off your service technician that this car is driven a little harder than just to the grocery store. Other than the color these two racing brake fluids are identical in performance.
Motul RBF 600 has a cost/ltr. of over double that of either the ATE fluids and has a Wet boiling point of 29F greater. The Motul RBF 660 costs almost 4 times that of either of the ATE fluids and has a Wet boiling point of only 7F more.
And then there is Castrol SRF. Clearly this is the "Gold Standard" of racing brake fluids. Its Wet boiling point is 126F higher than either of the ATE fluids and 97F higher than Motul RBF 600 but it also costs over 5 times per Liter more than either of the ATE fluids and 2.4 times per Liter more than Motul RBF 600.
The one fluid that is not a very good value in my opinion is Motul RBF 660. It costs almost $60/Ltr and has just a slightly better Wet boiling point than either of the ATE fluids. Unless you absolutely must have the performance of the Castrol 518F Wet boiling point, I would go with either of the ATE fluids or the Motul RBF 600. The other thing you should do is add some brake ducting to your front brakes to keep them as cool as possible. This will go along way toward keeping your brake fluid from boiling. You might ask what do I use in our Northstar Motorsports Porsche GT3RS? The sticker next to the brake fluid reservoir says "use only Castrol SRF" - and that's what we do.