I got V6 Accord running regular M1 5W20. I am very happy with the performance and wouldn't mess with M1 success. The oil always seem to be very clean and thin on the dipstick. The engine rev nicely and looks perfect through the fill hole. I am not sure I want to use M1 EP and change every 15k though. The price is more so I rather stick with M1 regular and change at 10k. Keeping the same oil in the crankcase for some long isn't a very good idea, regardless of what oil it is.