Hi Dwight. DOT 5 brake fluid is silicone based and not at all suitable for street use. Racing teams using DOT 5 fluid drain and flush their braking systems after every race.
Now DOT 5.1 is a glycol (
synthetic) based fluid and is DOT 3 and DOT 4 compatible and is an upgrade to a street brake system.
Lots of data on the web about the performance characteristics of DOT 5.1 and other similar performance fluids.
Cheers
Greg