You know that irritating "Change Oil" light on your dash that illuminates every 12 months regardless of mileage? Well, you can ignore it.

The first schedule oil change on the Corvette is 7500 miles or THREE YEARS!

Now, factory fill on the Corvette is a full syn., but this initial oil change interval is an admission by GM that the oil in an engine is affected more by mileage than time, and that the 1 year maximum oil change interval, regardless of mileage, is just a CYA by the manufacturer.

 

My opinion:

They'll get to sell an engine to anybody dumb enough to do that.

Both mileage and age are stupid-excessive in that case. I had a Kawasaki Ninja purchased new in 2000. The owner manual said 6000 on oil and 12000 on filter. I don't think so, Tim.

People with the, "I'm only keeping it for 3 years then trading it in." mentality are the ones who do that....anyone who loves their vehicles and cares about their well-being won't do that.

 

I can totally get a milage limit, whatever it may be, but time? I don't think oil gets "old". I have two vehicles that go YEARS, like more than 5 on 1 oil change. Neither will get remotely close to the mileage limit (8000 miles on full syn). A few hundred miles a year means long change intervals. One I've had for 30 years, the other 27.

 

Oil doesn't necessarily become "old" but it will absorb moisture over time especially when an engine sits idle without being run and building general engine heat up to its normal operating temperature.

 

If they have to write one rule for everyone, it will be overly broad and will not cover many scenarios adequately.

Oil doesn't get old sitting in a bottle or an engine. The other contaminants and moisture are the primary issues.

Ever see moisture on the inside of the oil cap on a car that doesn't get driven much? That same amount of moisture is on many surfaces in that engine. In the desert, you'll see it less. In humid regions you'll see it more. Etc.

I bet the GM 3-year/7,500 mile interval is more an admission that they've figured out how to balance the various use cases such that they have the least risk while making a selling point more appealing. Remember though, this is the same GM that had bazillions of 3.6 V-6's get their timing chains replaced on warranty because they would "stretch" due to excessive wear caused by extended oil change intervals. Part of the warranty repair was to update the PCM to make the interval more conservative. They wouldn't have been forced to do this except that the stretched timing chain caused emissions performance issues (well within warranty) when the cam phasers couldn't adjust enough to compensate for the stretch . . . and GM didn't want the lawsuits to include the federal government on the plaintiffs' side.

If you were keeping the car for a long time, what's a couple of extra oil changes? If it doesn't get driven much and it is new, you've already proven you can absorb a large financial hit in the forms of acquisition cost and depreciation for something that you don't use much. At that point, tens of thousands of dollars deep, the cost for a yearly oil change is small potatoes.

The flip side is, if you are only keeping a car for a few years and don't care about the next guy, do whatever, and leave the long-term problems for the next guy. We'll be happy to help them out here at FTE later when they have whatever issues because of this. Personally, I wouldn't sleep well knowing I saved a pittance doing this then dumped it on them, but that's me. I've been on the receiving end too often I guess.

It's also not just about the oil though. It's also a chance to inspect the vehicle . . . so that issues can get found and fixed . . . and often so that dealerships and shops can find stuff to upsell.

My $0.02 .