After all, they put oil in at the factory, right? So, no, if you don't want to change the oil, let the pump run till it drops. However, if you'd like to keep those pumps running for a few years, change the oil. Different pump manufacturers suggest different intervals, mostly based on hours of operation. While some car washes have hour meters on their pumps, most don't. In the car wash business, you should stay up and running if you change your oil every three months. It's important to look at that oil from time to time. If it looks black and slightly thick, or milky, change it and also check to see the cause of the colour change. Pelco Pump oil works in all Cat Pumps and General Pumps, as well as most Giant pumps. Check with Pelco for your brand of pump.