If your running your engine at the correct needle setting, they will all put out about the same amount of oil residue. If it's not throwing oil, it's too lean and your engine won't last long. Rather than try to avoid getting oil on your model, look at better ways to clean it quickly. Do a search on cleaning, you'll come up with a lot of ways to clean it off. I mix my own cleaner, one oz. dish detergent, 16 oz. Isopropal Alcohol, 111 oz. water. It cleans very well, and I use the cleaning time to look the model over for any obvious problems. By the way, I prefer the OS four strokes for their reliability.