Late model BMW automobiles have dealer recommended 10,000 mile synthetic oil change intervals. That is all well and good when the engine is brand new and still under warranty where if anything breaks, clogs, or is damaged the dealer will take care of it under warranty. Also good for BMW corporate as they don’t have to do many oil changes under warranty. 10,000 oil change intervals get really dicey once your BMW is out of warranty and has racked up tens of thousands of city miles in stop and go traffic. The 10,000 mile oil change number comes from BMW testing their brand new engines under ideal driving conditions. A mix of highway, town, and city driving are tested on a new engine with all new seals and parts while under warranty. Now if you car is at least 10 years old; nearing 100,000 miles; and spends most of your commute idling and revving up in stop and go traffic then 10,000 miles oil change intervals will cause premature wear. This will lead to leaks and premature component wear at the least or will cause engine failure at worse.
Oil has many jobs inside your BMW’s engine and becomes less efficient at performing those jobs the more miles the oil has been cycled through your engine. Oil works to cool, lubricate, and clean critical components. As oil is cycled through your engine to perform these jobs it starts out a golden amber color and as it picks up contaminants, moisture, and oxidizes through heat cycles it turns black and becomes thicker. As oil deteriorates it loses its ability to withstand high temperatures without burning. Once your oil’s tolerance for heat is reduced enough it will burn causing sludge to build up, greatly increasing wear and tear. This is a common problem with the BMW N20 engine installed in the BMW X1, X3, 3 Series, and 5 Series automobiles. Following the 10,000 oil change intervals on cars equipped with the BMW N20 engine causes excessive wear on plastic timing chain tensioners. They will suddenly fail and the engines will internally destroy themselves when this happens. This issue was so sudden and wide spread there was a class action lawsuit against BMW for this issue.
Engines experience the most wear and oil has to work the hardest during cold starts and stop and go traffic. That is why oil deteriorates faster in city driving where your car’s engine is constantly starting then driving short distances with lots idling and quick accelerating in between. Oil last the most miles in environments where the engine revs at a constant low RPM with lots of air passing through the radiator keeping everything at optimal temperatures. Our customers car’s tend to do the bulk of their driving in the city and therefore we recommend oil change intervals of 6,000 miles with synthetic oil. What if you drive your car less than 6,000 miles a year? Then we recommend you change your oil once a year. As oil sits in your engine moisture builds up in the oil pan and oil oxidizes becoming less effective.
6,000 miles oil change intervals are cheap insurance against premature engine component failure. And when you get your oil changed at a reputable shop like Bimmer Motors, you also will get a heads up in case something is worn, leaking, or we see something that might become a maintenance issue down the road. European luxury cars are not cheap to repair, but keeping up with standard maintenance in a timely manner goes a long way to saving yourself from large repairs bills in the future.