The Amsoil 10w-30 has shown excellent wear number in this motor and would be preferred over their 5w-30,given that you live in La. I'd change the SDF-42 oil filter after six months and change the oil after 15,000 miles or 1 year, which ever comes first.
It would be worthwhile testing the first two batches of oil you run after six months - prior to doing the filter change. The main reason to do this is to make sure the engine is running as well as it should. The Amsoil 5w-30/10w-30 are very consistant in terms of performance and will hold up extremely well, unless you are getting abnormal contamination from fuel,coolant or dirt.
At least 75% of my Amsoil customers run extended drains in vehicles under warranty and don't bother doing any oil analysis testing - except for the initial testing I just described to define optimum drain intervals. Once you do that, there is NO need to test every batch you run, unless you are just interested in oil analysis, or use it as a sales tool the way I do ....
If you work with an experienced Amsoil dealer like MSparks or Pablo, who understand lubrication/oil analysis,you'll get excellent results with the stuff....
Tooslick
www.lubedealer.com/Dixie_Synthetics
[ December 13, 2003, 09:53 AM: Message edited by: TooSlick ]