Quoted:
Mistake?  No.  ACtually you should be changing it every 6 months at least.  Time also breaks down oil additives and time puts contaminates into the oil.
SGtar15

Quoted:
There is no way that was a engine with only 30,000 mile on it . They said it had one oil change at 15,000 miles.

Something is up I have seen a engine on a Lincoln that was never oil changed , just had dino oil added, it was no where near the mess as that, something is up ??? I go 10,000 miles with synthetic oil all the time, check it constantly, looks just like it does at 3,000 miles, not like jello. Truck drivers almost never change their oil , it does not junk up after 100,000 miles -- b meter is pegged.In any event what if I showed you a engine with 50,000 miles on it clean as a whistle, just a little varnish -- the internet -- land where a picture  and a story is enough to change a persons life, go figure.

Quoted:
Actually there is a documented problem with the V-6 engines that Toyota uses for the Camry.
The oil return passages are too small, so when the oil gets gunky and deposits form in the return passages the oil gets stuck and does not return to the pan which causes the main bearings to lock up.

Do a Google search.

As an engine sits idle, not being used, it is subject to day to day changes in ambient temperature and humidity. Internal engine components, as well as the oil in the engine itself, are subject to moisture accumulation caused by natural condensation from these changes. If an engine is not run for an extended period of time, the oil film, that was left on any individual component within the engine at the last shutdown, deteriorates to a point that allows the accumulated moisture to make contact with the surface the oil was on. Corrosion of that surface will result. At the same time, accumulated moisture in the engine oil reacts with deposits in the oil that have developed from normal engine operation. This reaction can cause the engine oil itself to become acidic and corrosion on the part that the oil is trying to protect will result.

The only true protection we have against any of these corrosive elements is keeping the engine oil moisture and acid free and physically on the internal parts of the engine. This allows the oil to prevent corrosion from occurring.

Driving the car and engine long enough to develop an oil temperature of at least 160 degrees fahrenheit for 30 to 40 minutes will remove almost all corrosive elements, that build up in the oil from its non use and exposure to the atmosphere. This process also provides a fresh renewed protecting film of oil, that contains little or no moisture or acids, on all internal parts of the engine at shut down. This film of oil does not last forever and if enough time elapses between engine runs, the internal parts of the engine will become subject to corrosion all over again. The only way to prevent this is to drive the car, as prescribed, fairly often. This will repeatedly burn the moisture and acids out of the oil, as well as providing a continuous renewed film of protecting oil.

Another consideration of the ability of the oil to protect against corrosion, is the amount of combustion by products and engine produced deposits that are present in the oil. As previously mentioned, running the engine will remove most of the harmful contaminates present in the oil. However, it will not remove all of them. The longer an oil is run in the engine, the more contaminants it has a chance to absorb. The more contaminants present in the oil increases the likelihood of a reaction with those contaminants that can cause corrosion. Consequently, changing you oil frequently will help reduce the possibility of corrosion as well.

Quoted:
If you only drive the car 10 miles a week then their is no reason to still change the oil every 3 months, or six months for that matter. Doing it once a year with those kind of miles is great and won't cause you any problems. You are actually driving with cleaner and less broken down oil then you were when you were changing it every 3 months or 3000 miles before. Oil will break down super slowly over time while it is sitting in your oil pan. I would recommend allowing the car to warm up well before driving it especially when you are only driving it 10 miles per week. Give the oil a chance to lubricate the engine and that is the best thing you can do for it.

Quoted:
If you only drive the car 10 miles a week then their is no reason to still change the oil every 3 months, or six months for that matter. Doing it once a year with those kind of miles is great and won't cause you any problems. You are actually driving with cleaner and less broken down oil then you were when you were changing it every 3 months or 3000 miles before. Oil will break down super slowly over time while it is sitting in your oil pan. I would recommend allowing the car to warm up well before driving it especially when you are only driving it 10 miles per week. Give the oil a chance to lubricate the engine and that is the best thing you can do for it.

Quoted:
How about the other oils like the differential?  I was at a qwickylube, and the guy shows me a swipe of my differential gear oil, it was a brown smear.  I asked him how important it was to change it, did I really need to.  He said most people don't even know it's there, much less change it.

Get this, I work for the Airforce and in an effort to reduce the multitudes of lubrication (and other hazmat) products, they have switched to just using 30weight for everything - engine, differential, hydraulic, etc... We sure are burning a lot of differentials out (since we don't use 90w anymore).  I'm not sure about all the other products, places, or equipment, but this is the new rule our company is being forced to operate under.

Other anecdotes.  I like Mobil-1 synthetic, it's a lot more expensive, but handles temperatures better than most.  Consumer guide did a study and found most all oils to be about the same, only a couple were inferior, and the synthetics were better.  I bought an old Cutlass Supreme one day and used some duralube/slick 50 type product, and it really did make a difference in my compression and gas mileage.  However, it doesn't last, has more effect on aged engines, and is nice incase you your engine dumps all your oil and you got to make it to the next closest place to repair and refill.