when i start the car i turn them on where i take the car i make shure i sit a round for 1 hour i do not drive this thing all time. this thing with the 548 blown big block in it and runs on race gas and is 10 psi on boost and and is 10to1 cr it is a land rocket so i do not hang out on the road to long with 4inch ex the cops my be comming? but i can leave the fans on as long as i want