The only significant difference between the two of them is maintenance. Which one you want to buy depends on your use. Have a look at the features of both of them: Oiled pump: As its name suggests, an oiled pump air compressor uses oil to lubricate its moving parts. If you want to buy one for the business, an oiled pump air compressor with a high CFM and PSI will do a better job for you. However, do keep one thing in mind, you need to maintain them properly to get the full out of them. Furthermore, they don’t work best in cold weather. Oil-Free: Unlike an oiled pump, these air compressors use wearable parts that use friction-reducing chemicals to lubricate themselves. They require no maintenance and can work perfectly even in cold weather. If you want to buy one for the home, an oil-free air compressor would be better. As they are lightweight, efficient, and easy to carry around. The best thing is that they don’t need any oil and filter to be maintained from time to time.