Originally Posted By: paulgoh
Originally Posted By: ConfederateTyrant
For that long of an interval, your wear numbers are in great shape, and viscosity wasn't horrible given the 25,000 mile interval. From the looks of the zinc and phosphorous, this may be the old SL formula, which was prone to thickening, but it went from ~11.5 cSt to 14.7 cSt, which is not a big deal, in my opinion. TBN would be nice to see, but perhaps 20,000 miles would be a good limit from now on.
Hmm....the Amsoil oil is rated for 35,000 miles so I thought I'm under-using it by doing 25,000 miles. Also, I'm not sure if the duration of the oil usage (i.e., 18 months) have anything to do with the wear and tear of the engine and the oil does not seem to have accumulated any water. Perhaps I could try to replace the oil filter and let it go another 10,000 miles before draining at 35,000 miles?
Lets see what Amsoil says;
Quote:
• Normal Service(3) – Up to 35,000 miles or one year, whichever comes first.
• Severe Service(4) – Up to 17,500 miles or one year, whichever comes first.
• Replace AMSOIL Ea oil filter at the time of oil change up to 25,000 miles or one year, whichever comes first (other brands at standard OEM* intervals).
See the part about ONE YEAR.
Also;
Quote:
(3) Personal vehicles frequently traveling greater than 10 miles (16km) at a time and not operating under severe service.
(4) Turbo or supercharged vehicles, commercial or fleet vehicles, extensive engine idling, first and subsequent use of AMSOIL in vehicles with over 100,000 miles, daily short trip driving less than 10 miles (16km), frequent towing, plowing, hauling or dusty condition driving.
So if your doing anything that would be considered severe use (like driving HARD) your
up to 17,500 miles or ONE YEAR.
You have gone over a year. The filter is rated for a MAX of 25k or one year.
CHANGE THE OIL and next time, take it to a max of 20k or one year IMO.
Unless you don't want to see high miles on this engine without problems. The oil is TOO THICK even for CA weather (again IMO).
For a engine that would be happy with a 5w-20, I'd go with Amsoil ASM 0w-20 for a max of 25k or ONE YEAR over anything else for a long OCI.
Thanks for posting this UOA. I've learned from it.
Bill