Engine oil now operates camshaft timing and other vital functions effecting power, fuel economy, and emissions. Car manufacturers have been trying to vary the camshaft timing of the intake and exhaust valve openings for years. While it became common place on racing car engines in the 70’s and 80’s no major manufacturer had been able to reliably incorporate it into production engines until Alfa Romeo introduced it on its fabled two liter twin cam four in 1982. Even then, its performance was unreliable at best.
The breakthrough came with the convergence of several improvements and changes in engine design. Firstly, the thinner lubricants, such as 0/10 weight engine oil, used to lower emissions and improve fuel economy came out, along with the improved machining technology needed to maintain the close tolerances required to use such thin oil. Secondly, increasingly sophisticated engine management computers became capable of improved multitasking, and thirdly, intelligent CAD programs allowed engineers to design and test different cam control configurations before putting them into production in millions of cars and trucks.
The results all come together when you step on the gas in your late model car or truck. The interface between foot and road is so transparent that it is almost impossible to tell if you have a turbocharged 1.4 liter engine or a normally aspirated 2 liter. But there is a catch 22. Because the engine oil no longer merely lubricates rotating engine parts, the quality and cleanliness of the oil is more important than ever. Extended oil change intervals combined with higher temperatures from turbo charging conspire to degrade oil much faster than in the past. Short trips around town exacerbate the situation.
We recently replaced the timing chains, cam timing regulators and the solenoids that control them in a 2015 Mazda. The bill was over $3,000. When we looked at his service history (not a car WE serviced), we found that he had changed the oil exactly twice since he bought the car, once every 15,000 miles, just like the owner’s manual told him to. Our recommendation is to change the oil at least once a year, or more often, no matter what the manual says. And if you typically drive the car on short trips around town combined with occasional freeway blasts to LA or San Francisco, consider changing it more often. Our service advisors, Jesse and Elena, can tell you how often is best for your use, but the bottom line is change your oil!