Question: I was reading an article recently that said changing my oil every 3,000 miles is an outdated idea that costs me more money and is bad for the environment. According to the article, today’s oils can go 5,000 miles or more and I should look at my owner’s manual to see how often the oil really needs to be changed. What do you recommend at Auto Lab?
Answer: If your car uses conventional motor oil, such as 5W30 or 10W30, we recommend changing the oil every 3,000 miles or 3 months. If your car uses synthetic oil, we recommend an oil change every 5,000 miles or 6 months. You can push that to 6,000 or 6,500 miles if you almost always drive on the highway.
Why? In short, oil is cheap and engines are expensive. In my own car, I use synthetic oil and change it every 5,000 miles.
A lot of carmakers have tried recommending longer oil change intervals, and in a number of cases, it’s come back to haunt them.
Ford had been recommending an oil change every 10,000 miles, but the engines began to fail at a much higher rate than normal and they had to replace a lot of engines for free. They’ve since backed the interval down to 7,500 miles.
If you Google “Mini Cooper” or “Toyota” and “sludging,” you’ll see a slew of information about the problems consumers have had with their engines and their extended oil change intervals.
Modern engines are made with such precision, such tight passageways, that clean engine oil is absolutely critical. If you push your oil beyond its useful lifespan, it starts to break down. It turns into a jelly—or sludge—and it starts to clog these passageways. If that happens for a long time, the clean oil can’t circulate properly, and it causes all kinds of expensive engine problems.
While there have been a lot of improvements in today’s vehicles and in oil, tires, etc., we’d rather err on the side of caution and change the oil more often than risk damaging the engine, which can cost thousands of dollars to repair or replace.