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.
Wheels:
Dick of Michigan writes: “I just purchased a 2011 Buick Lacrosse and in the owner’s manual (yes, I did read it) it states that dexos oil is required to be used. I have not been able to find this oil at the local big box store. What is dexos and is it really needed compared to using good quality SAE 5W-30 oil?
Halderman: Dexos is the oil specified for use in all General Motors vehicles starting with the 2011 model year. Dexos 1 is specified for all gasoline fueled engines and Dexos 2 is specified for use in all diesel fueled vehicles.
While there are two new oil standards that became effective in 2010, General Motor Co. still created a separate specification for use in General Motors’ vehicles (Buick, Chevrolet, GMC trucks and Cadillac) and Dexos is backward compatible, meaning that it takes the places of other specification such as 6094M and the Corvette engine specification. This means that Dexos can be used in all General Motors vehicles.
Some interesting information was released when Dexos was announced including:
• Engine wear is now measured in “atoms per hour.”
• Oils must be formulated to prevent aeration as any air in the oil can affect the operation of variable valve timing control valves and variable displacement engine systems.
This means that it more important than ever to use the specified oil. The days of the $20 oil changes are over, as is $2-a-gallon gasoline. Today’s engines are more efficient, but they require that they be serviced at the specified intervals and that the specified fluids be replaced.
If you cannot find dexos, try a local dealer as they will have it until the oil companies start manufacturing it for the do-it-yourself market which may take a year or more.
• Note to readers: It is now officially spring and time to have the oil changed and perform other automotive services as specified by the vehicle manufacturer. The services usually include:
1. Oil change
2. Air filter inspection
3. Cabin filter replacement
4. Windshield wiper blades replacement
5. Tire inspection
6. Spring cleaning
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