I have the valvoline brake fluid in my vehicle.
The Synpower is not listed on their website....however when I clicked for the data sheet for the data sheet.....it lists the synpower with a dry boil point of 503F and wet boil point of 343F
The "Synthetic DOT 3&4" product lists a dry boil point of "Up to" 480F.
My last bleed was with the "synthetic" so I have a mix of "Synpower" and the synthetic DOT 3&4.
I am SURE that this product is good enough for my daily driver.
Looking on the Pegasusautoracing website, under "fluids and supplies", brake fluid.....
These are DOT4 and compatible with other DOT 3, 4 & 5.1 fluids.
DOT 5 (no .1) is not compatible with these fluids......
They have the Castrol SRF (DOT4) in 1 liter container for $79.99
Dry boil of 590F Wet boil of 518F
The ATE that Dualie mentions, comes in "Super Blue" (blue color) and "Type 200" (amber color), Identical other than color so that you can alternate between colors when doing a full system bleed.....and you can know when you get the new stuff out the bleed screw.
$14.99 for 1 liter container (both DOT4)
Dry boil of 536F Wet boil of 396F
They have other kinds also.....listed in a table.
You pretty much need to get these from a racing supply house.
Some brands of fluid claim "Low moisture absorbtion properties" or as having moisture handling capabilities.
It is a normal tendancy for brake fluid to absorb moisture.
For this reason, it is best to use fluid from a new bottle.....not one that has been opened and sitting around the garage for who knows how long.
Folks who run their cars at the track often bleed their brakes between each run.
For my daily driver, I like to bleed my brakes at least every other year.