Oil Change Interval 3,000 miles......

That's comparing apples and ham. One is a diagnostic test and the other is a wear item.

How often do you guys change tires? Assuming the tire isn't rotting, do you change them before they hit some wear point you are comfortable with (say the wear bars)? Do you automatically change them every X number of years regardless of wear (and again, assuming no tire rot)? Do you change them when there is only 25% wear, just to be safe?

As for compelling reasons, you're certainly not hurting the engine by changing it too often. The only downside is waste, both money and oil itself, but you're not getting any real benefit from doing it.

That's why you send off for an oil analysis, it will tell you how much of the oil is broken down, how much and what kind of contaminents are in the oil, etc.

3k miles on 12 qts of synthetic (hell even regular dino) oil is almost always going to be wasteful, except under the most extreme conditions. Modern oil is not the same as oil most of us grew up with, especially when we're talking synthetics.

 

Oil and spark plugs are both diagnostics and wear items. Hopefully you'll never notice anything unusual in the drained oil, but it's cheap and safe enough to have a look.

With regard to tires, I swapped out a set of 7-year old Michelins for new Goodyears last year. The old tires had no visible wear or deterioration. I guess it comes down to an "Are you feeling lucky, punk?" proposition. It's established that tire rubber loses its performance after 5+ years. For sedate driving, you can probably go longer, but when that panic stop or emergency manouevre comes along I think you have to decide how important your tires really are.

Frankly, if there's a 2% chance that changing tires, or oil, could save my life or a Ferrari engine, that's enough. This is the cheap stuff in Ferrari-land.

 

Right, you are using some level knowledge to determine that an old part needed to be replaced. Say those tires were a year old, you likely would not replace them becuase as you said, tires lose performance after X number of years and you're not past that point. That is a little different than just changing your oil for no "real" reason as it sounds like hardly anybody knows if their oil is "worn out" or not.

And yes, oil can be a great diagnostic, but I don't know about you, but just looking at oil doesn't tell me jack about what is in it. If you're seeing metal in the old oil you've likely already done some damage to the engine (anything big enough for you to see has done wonders for various bearings, journals, etc), let alone water, fuel, etc contaminents.

 

Why wonder? Just send an oil sample to Blackstone Labs and let them tell you if your oil change interval is too short/long, whether you've got coolant or fuel in your oil, what your wear numbers are, etc.

http://www.blackstone-labs.com/

 

Me too........

 

My manual states the oil filter can be changed every other oil change. So at the factory recomendation of 7,500 miles between oil changes, that's 15,000 miles per filter change.

Okay, soap box time...

As far as annual oil changes no matter what, that just doesn't make sense! If you change your oil and NEVER drive the car, you will still get condensation and you will have to change the oil again the next year with zero miles! Might as well just pull the drain plug and leave it out!

Contamination!? How does that happen if you never drive it? Besides, isn't that what the filter is for? And if you are getting that much contamination on short drives, then you have severe blow-by past your rings, which means you have bigger problems to deal with.

Then what about everything else? Here you are, making sure you get the condensation out of the engine while the gearbox, wheel bearings, brake calipers, cambelt bearings etc. are filling up with it and rusting.

The EASIEST, SIMPLEST, and FUNNEST solution to condensation is to DRIVE THE CAR, at least once per year. Take it out on the freeway and put 60 miles on it. The heat buildup will remove the condensation from ALL of the moving parts.

Just seems to be human nature though. If the recommended schedule is good, more often is better, and extreme is the best.

Off my soap box...

However, changing your oil every day won't hurt anything, will it.