No, not automobile fans but electronics ones. I have a gadget that uses two brushless DC fans. It is rated at .8w and I am wanting to replace them. Trouble is I can't find the same rated fan - it has DFS 4010 12M on it - without paying silly money. I can get other wattage fans in 40x40x10mm so my question is........will I be OK to use a lower or higher watts fan?