It is important to make sure that you do have clean oil and get it changed regularly. but to also make sure that they actually do put oil back in your car.
My last car, had the engine die on me from what me and my mechanic think was *insert company here who I don't want to bad mouth publicly* not putting oil back in the car after changing it. I had some other work done and thought it might be related to that, and took the car back to them after the engine died on me. So who knows if that was the cause or not.
Oil changes are something important for your car.


