I'm nearing 8 hours on my Timecutter w/FR691V 23 hp. Picked up a Kawasaki oil filter and 3 qts of John Deere Tough Guard 10w30 for the 1st oil change and noticed Tough Guard had an API classification of 'SN". The Kawasaki specs call for SF, SG, SH, SJ, or SL API classification . IF I...