Is it better for you engine to warm up before driving? Cars with electronic fuel injection do not need to be warmed up before lightly driving off. This is because fuel injected engines can compensate for temperature changes. Cold engines run rich to compensate for poor fuel atomization. This means extra fuel is injected into the combustion chamber. Now fuel is a solvent, so when extra fuel gets on the cylinder walls, it washes away the oil from the cylinders and pistons. Less oil on the cylinder