do the cooling additives like 40 below, 28 below, water wetter, etc., really help cool the radiator down more? & I'm curious(if there is anyone who really knows) the two product probleand make 28 degrees below, & 40 below, as their names inply they are suppose to lower radiator temp 28 degrees & the other 40 degree, do they really work that much, or are they snake oil?