I have a much better idea. Just take a hammer and chisel that'll fix it real good. Why would you want to use an impact driver on an oil drain bolt. I understand that sometimes they are really tight, it should never be that tight that you need an impact driver to get out the oil pan drain bolt. You could end up snapping the bolt head off. Then you'll have some real problems. I would use the idea that someone else had and get a breaker bar. Leverage is your friend. If you feel like you're going to snap it, take it to what ever dealer did the oil change last time, this way, when they snap the head off the bolt it will be their problem, not yours. Drain bolts for oil pans never need to be that tight. Engines don't build pressure in the oil pan, all the bolt does is hold the oil in. When I do my oil change on my car I screw the Bolt in by hand and then snug it down, just snug it. I know that Honda calls for something like 29 foot pounds. In my book, that's way too tight for an oil pan bolt . We're talking a steel bolt into an aluminum pan. Great way to strip out the pan.