dot 3 or dot 4 brake fluid

The WSMs advice using Dot 4 fluid in the brake system and the owners manual suggests Dot 3 or Dot 4. The cap on the brake master cylinder is stamped Dot 3.
Dot 4 has a higher boiling point suggesting that its the fluid for harder use although I'm not sure our cars braking system gets to the higher temps even with hard street use.
Any thoughts? TIA...............Malcolm
Many track drivers use ATE Super Blue, but it is changed more often then typical street cars.
I have also used the Castrol DOT 4 synthetic, but like the super blue. Also, as it is available in different colors, it makes a full fluid change/bleed SO MUCH EASIER!
***Call 928 Spec and get the "Power Bleeder" . Makes the job FAST and EASY! By far, the best $39 I ever spent on a tool!
Castrol LMA is good fluid, as is the ATE, and as is any name brand synthetic DOT 4.
Do NOT use silicone fluid!
My recommendation is Valvoline SynPower synthetic formula. It has a dry boiling point of 480F and a wet boiling point of 330F - higher boiling points than either Castrol or Ate and it's readily available at auto part discounters for around 5 or 6 bucks a quart USD. Ate is usually at least twice as expensive.
James


