Reader asks about synthetic oil

Wheels: Jeff from Chicago asks by e-mail: “I have a 2007 BMW 525i. I drive 98 percent highway miles. I drive for maximum fuel efficiency even to the point of being a bit slower than average traffic. I drive 5,000 miles a month, nearly all down interstate and major state highways in rural America. My BMW was built with an inline 6-cylinder engine. I am getting 36 mpg average, and have done as well as 42 mpg. Now for my question: A BMW oil change is $100. I read the recent article on synthetic oil and high mileage changes. I would prefer to change my oil at 3,000 to 5,000 miles and use standard, non-synthetic oil.

It seems to me the economics of this decision include your driving conditions and habits, but also how long do you plan to keep the car. If you take care of a piece of equipment like you plan to keep it to 500,000 miles, then you just might succeed at this.

If I change the oil frequently at $100 a pop, that’s a lot of money. I think this is all marketing hype. What is happening is the manufacturer is trying to get the consumer into the dealership frequently. The cost of maintaining the car is soaring because of marketing design.

I like the idea of keeping the oil clean. It strikes me that given the low level of stress my oil is given, it doesn’t matter. The manual says synthetic oil only. The car is designed so that it is impossible for a regular citizen to change his own oil because he can’t reset the stupid monitors. Do you have any thoughts on this matter?”

Halderman: For the detailed answer, go to jameshalderman.com and select “Power Points” and then look at the one on engine oil. There you will see that BMW and other European vehicle manufacturers use a different rating system for oil compared to those used in the U.S. They also specify oil that has a very broad viscosity range, such as SAE 10W-60, that is not found in oils that do not meet the BMW (ACEA) standards. Severe engine damage and sludge can occur if standard API-rated oil is used instead of the specified oil. However, the good news is that BMW specifies (check the owner’s manual to be sure for your vehicle) 30,000-km (18,000-mile) oil change intervals. This means that even though it might cost $250 for an oil change, including having all of the electric oil pumps run using a scan tool by the shop to rid the system of air, it is actually about the same cost if you used conventional oil and changed it every 3,000 miles.

Always use what the vehicle manufacturer recommends. They know more than we do about what is best. Besides, with the distance you travel, I would think that changing the oil every 18,000 miles is an advantage and you will not have to spend as much time changing or having the oil changed. I hope this helps.

James D. Halderman is an ASE-certified master technician, a member of the Society of Automotive Engineers and the author of 12 textbooks. Submit your automotive care questions to Halderman via e-mail at jhalderman2@juno.com, or write him in care of: Wheels, Marketing Publications Department, Dayton Daily News, 1611 S. Main St., Dayton OH 45409.

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