What kind of oil should i use in a john deere lawn mower

Unless you're operating your John Deere lawn mower at temperatures above 110 degrees or below zero, 10W-30 will protect your engine. At extremes, go to 5W-40.

Friday, May 18 2012
Source: http://www.ehow.com/about_6509963_oil-john-deere-riding-mower_.html