Oil Life

[broncobilly_69]

My Bronco only gets driven about 3-4k miles a year and not under severe conditions. I've been changing the oil every six months because I've been told that even though it doesn't have that many miles on it, the oil goes bad from sitting in the engine. Anybody know anything about this and if I can get away with only changing the oil once a year? I've been using Mobil 1 full synthetic.

 

[Indybronco]

A quality synthetic like Mobil 1 can easily go for 8000 miles (or roughly 3/4 year) when used in a daily driver so I see no reason why it would not last for a full year given the low mileage you put on your truck. If there is any doubt along the way just get an oil analysis done at the six month mark and make your decision from there. I'd be surprised if you have any issues.

 

[cgbexec]

Oil does not go bad sitting in an engine. The reason you should change the oil at a time interval is because of contaminants that enter the oil, mainly moisture. If you store your vehicle outside, the engine heats up in the sun and the air inside expands. At night the air cools and condenses forming water droplets to form in the oil and on the inside of the engine. After the vehicle has sat for a while without running, eventually the inside of the engine begins to rust as there is no protective coating of oil to stop this reaction. This oxidized metal finds its way into the engine oil eventually. This process happens if you keep the vehicle inside as well, but the condensate does not build up as quickly.

My suggestion is if you keep it outside or in an area that has a wide temperature swing to keep changing the oil every 6 months. If you have less humidity, and less of a temperature swing, you can probably get away with 1 year intervals. In either case I would start and run the vehicle up to operating temperature at least once a month or more often if possible. This will do two things. It will dispell the moisture that has built up in the engine by heating it to its steam point and it will coat the internals of the engine with a protective coating of oil. Never just start an engine, let it run for minute and shut it down. This just mixes the water with the oil and does not remove it.

Chris B.

 

[wildbill]

What kills your oil is very short drives not getting it hot to burn some of the crap out. It will make it slugey over time. Take it out and drive 20 to 30 miles once a mo. or so and get it good and hot you should not have any problems. Good luck and have fun.%) %) %) Bill %) ;D

 

[cgbexec]

Wildbill elaborated on my point above. You need to get the engine hot enought to steam the water to the point where it can be pulled through the PCV valve and burnt by the engine.

I am in the marine industry and we deal with big engines in a very humid environment. The biggest killer of marine engines is letting them sit and not running them. We pull oil samples on marine engines and send them out for lab analysis. Engines that are run less often always come back with much higher contents of metals and moisture. Engines that are run more often always have less metal and moisture. I have seen engines seize with just a 100 hours on them, but they are 5 years old. I have also seen an engine run 15,000 hours and live to be 15 years old. The low hour engines are sitting and building moisture which in turn corrodes the inside of the engine. Then you start it and all of that corrosion ends up in the oil doing more damage by increasing friction sludging up. Sorry for the long explanation, but I figured it pertains to all of us Bronco owners, especially the ones whom don't use theirs as daily drivers.

Chris B.