Excuse my ignorance. But the Prius is my first car ever so i have limited knowledge about cars. The engine sounds louder and not smooth when i accelerate on local roads with a cold engine(engine coolant temperature is 50F, 2500RPM). The ambient temperature is around 30F. Are all car engines run rougher when the engine is cold? Once the engine coolant is hotter (100F+) the engine is smoother. The engine feel very smooth when the coolant reaches 180F.
Yes that is perfectly normal. Nothing to worry. I always try to go easy on the engine when it is warming up. I don't like the sound of a cold engine anyway, so I drive smoothly and slowly the first few minutes.
