I've been throwing around the idea of trying GC in the Accord. Nothing wrong with the M1 EP I'm using now, but being the oil addict that I am, I thought of trying this. I have about 12 qts of RL 5w-20 also that I'm thinking of using as well. My concern is making the engine sluggish. Runs great with the 10w-30 thats in it now.