Silly question... I've got a brand new container for unleaded that I bought for the petrol brush cutter... But it's never been used. Can I put diesel in it for my car... My replacement accord is sitting on my drive until the new year and I want to put some more fuel in it as it's getting low and I don;t want to pick up any crap in the bottom of the tank... I also want to throw a little diesel cleaning fluid in with it, and run the car for a while. Poor thing has been sat without going anywhere for a couple of months now and won't be swapped over until the new year.