[azpyroguy]

Dont know of a test but just use it all the time and you should be fine. Make it work a little too.

I just use mine all time as well (when I am towing), it has become second nature to kick it on when I am towing my 40ft 5th wheel...

Though I don't use it when I am not towing.. dont see the need..

Last time I towed I was coming down from the rim (south of FlagStaff), back in Phoenix, and there are quite a few 4-6% multiple mile downgrades, and I used is continuously there... and never ONCE had to touch the foot brake, and my speeds maintained around 47-55 mph.