extended oil changes and condensation?

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Jan 2, 2006
New Orleans
I thought it was recommended not to extend oil changes past 6 months due to condensation. Recently I've read several post of annual oil changes. What's the scoop on condensation and extended oil changes?
Good question....I believe this is why some limit the OCI to 1 year to protect against any excess condensation buildup. Most oils are formulated to withstand moisture. And I also believe that the oil once it reaches temp will evaporate off most of the condensation inside an engine. Extended oil changes really are not that new...Heck, most OEM's said 7,500 miles was acheivable a decade ago. Most folks only drive on the average of 12,000 a year.What little consendation occurs most likely will be burned off.
My '05 (GM) Opel Astra 1.8 has recommended OCI 20,000 miles or 2 years. I'm changing it once a year or at 10,000 miles as I plan to keep this car.. Annual OCI's (or up to 15,000 - 20,000 miles) have been the rule in Europe since the late 90s.
Most of my trips are less than 6 miles and often in heavy traffic. I went with Castrol Syntec and will only have about 4k miles at the 6 month point.
Most of my trips are less than 6 miles and often in heavy traffic.
Just an educated guess, your not getting your oil hot enough to burn off the potential condensation and fuel. But maybe there is no condensation and fuel to burn off, or if there is, it's benign. Under your conditions, it would seem prudent to change oil every 6 months. Castrol Syntec is reasonably priced. You could have a UOA done, but then you could use that money for your next oil change. I personally would skip the UOA, unless your were just curious.
9 months, 3,000 miles. My posted UOA showed NO water dilution. Condensation only has two potential routes into the sump of an idle engine: intake tract or exhaust tract. In either case moisture would have to traverse past the piston rings, which make a pretty good seal against the cylinder bores at normal atmospheric pressure, or the PCV valve, which itself is spring-loaded in its closed configuration unless the engine is running. Water is a natural byproduct of hydrocarbon combustion. If there's water present in a UOA report, it's from accumultated blowby past the rings because the engine was not always warmed sufficiently to evaporate it off and blow it out the exhaust pipe during operation.
I have been changing the oil myself for about 2 years, having a Toyota 92 Camry 2.2 and an oil filter easily accessible(top of the engine), this convinced me to give it a try...it is very easy and you know that the job is well done.
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