The Advice:

In response to the video where a customer drove his/her Kia sedan 135k miles without an oil change, and only brought it in because it wouldn’t pass emissions testing.

p*****h 9 months ago
135k mi and the only prob was it didn’t pass emissions. What’s the point of all these new longer lasting engine oils if you still “have to” change your oil every 3-5k miles.

Source: https://www.youtube.com/watch?v=KC-SxrsgEwo

Oil is better now than it used to be, but that doesn’t mean its a permanent fixture of your car! Being showcased in their comment is the idea that just because the engine runs, means everything is fine. Don’t forget that a modern engine can run with severe wear, however it will be at reduced efficiency and performance. And obviously, it won’t last as long. With an oil change interval like this, internal clearances will be out of spec and oil passageways will be restricted. At idle, this may not matter as much; however, very precise engine clearances are not as necessary at idle, as long as your oil pressure is high enough. They are required for high performance applications, especially high RPM, where intense G-forces exist and larger oil flowrates are required. If this were on anything other than a Kia sedan, this may be more of an issue. G-forces on a Formula 1 engine’s main bearings can exceed 50,000g’s, and clearances that are out of spec will lead to rapid engine disassembly, and you wouldn’t want this happening to your beloved project car.

Clearances and non-restricted oil flow are important so that when you do this, your engine doesn’t end up like that. I’ll leave my opinion of Hyundai to myself at this point.

Now, if you watched the original video, why did the car fail emissions? I’m only guessing here, but likely the PCV valve (or equivalent) was plugged, resulting in high crank case pressure. This will lead to engine seal leaking, and on many newer models, a check engine light indicating the problem. Also, a few frequent oil and filter changes with a high detergent oil could have cleaned the engine without requiring disassembly. If the emissions problem was anything other than a PCV system issue, then cleaning the engine wouldn’t help anyway. The damage had already been done at this point. Share your hypothesis with the class in the comments. What happens to engine oil after this obnoxious amount of miles is the subject of another article.

Leftlanebrain