I have just recently gotten a 2007 KingQuad 700 atv. It only had 129 miles and 32 hrs on it when I got it. I road it once so far and it was a good decent ride. I may ride it one more time or may not before changing the oil. It is the original factory oil in it and never has been changed. I want to go synthetic oil but not sure what is the best ones to choose from in oil and filters. It calls for 10w40. You can go 10w30 on cold side and 20w50 for the hottest side. 10w50 is next one above 10w40 in the manual. I don't plan on doing a lot of winter riding if much at all. My concern is the summer months.