Can you use diesel to flush out your old oil in your engine before oil change?

I wouldn't do that because, although it may well dissolve a lot of the impurities it's not nearly as good a lubricant as the oil and the bearings would not like it. You'd be better not to use anything. What gain do you think you are going to get from flushing? I called advance auto parts and auto zone. Both persons I spoke with said diesel fuel to flush engine works better than any engine flush they have. Just idle for 5-10 minutes. Don't drive it though until after oil change.