I have had exceptional service using IMRON on engines. I drive all of our cars, and for long distances too. IMRON will withstand the obligatory spilled gasoline and occasional antifreeze that at sometime manages to get on every engine that is in real service, and you will be surprised at how well it looks after many years. And I mean years! It is important that you use the proper primer with IMRON when painting over bare cast iron. There is a certain primer product for IMRON called "paint to metal" ( I think that is the name?) that MUST be used or risk the paint peeling off even with self etching primer as a base coat. Don't ask me how I learned this. I think you will like every aspect of this paint except the price and the toxic nature of the product. Both mix and paint it outside if you have no booth and stay upwind from the vapor and things should be fine. It can be flattened to get the needed sheen you want. Just one persons experience and something to consider when searching for engine paint. And to answer your question, there has never been an issue with tempreture causing problems with the paint except on exhaust manifolds.