One of my friend's mother car 1985 VW carbio rabbit has 222,000 miles. I asked my friend if her mother vw burning oil or not. He said very little oil burn and her rabbit running on 10w-30. Should he put 10w-40 or 15w-40 since the mileage is too high 222,000 miles. I am going do put 16oz of Lube Control engine flush to clean up sludges out of the motor then put 1oz of LC in each of the spark plug hole to soak the piston for 24 hours to remove the carbon and put new oil in motor. Should he stick with 10w-30 as usual. His mother work as nurse in San Fransisco General Hospital. It has lot stop and go for many years. What is your recommend.