or pop down your local ( helpfull ) car spares shop and buy a rad fan switch with the different temps , if you find out what your one is ( this is normally stamped on the bit that screws in the rad it will say to numbers ie 89/79 for example, then you buy one with 89/72 or something like that which will keep the fans on for a bit more or go for 87/70 for example this will get them working sooner and off when its cooler than normal ,it all helps