syn oil is good.!!! if you ever put syn oil on a dip stick and put a lighter at one end the syn oil attracts to the heat.! regular oil tends to run from the heat. and my R loves to drink oil... syn oil cost money but so does speed.=( i use penzoil syn oil 10w-30 all 5.25 qts because of my moroso oil pan( i gets it fo free! haha the perks of workin at a honda dealership)