Failure to use the right oil, use proper filtration, or observe proper changing intervals can affect the performance of even the best motor oil. This also includes changing the oil too often (needlessly bad for the environment and your wallet) or not often enough. Against conventional wisdom, engine wear decreases as oil ages to a certain extent, which means that changing your oil more frequently actually causes engine wear; these findings were substantiated by studies conducted by the auto manufacturers and petroleum companies, leading to drain intervals increased from 3,000mi to 5,000-7,500mi in most domestic vehicles.
Most European manufacturers have variable service intervals up to 30,000 miles. Many owners with vehicles using "long-life" or "extended performance" oils with long service intervals have found it best to reduce those intervals by half or even a quarter. Even Porsche, for the 2008 MY, significantly reduced the recommended 20,000+ mi/2 year drain intervals for new and old Porsches alike, down to 12,000 miles or 1 year. Based on UOAs provided to us by our customers, new Porsche owners should consider reducing their drain intervals further to no more than 9,000 mi or one year. We in fact recommend a 6 month/5,000 mile interval for normal service (severe service requires much more frequent servicing) where used oil analysis is not being performed to monitor oil and engine conditions.
Drain intervals can vary based on service life and the severity of duty your engine sees as well as the formulation of the motor oil you are using. Most racing oils intended for severe duty in high performance engines have less detergents, so their starting TBN, or total base number, is lower than these long life oils. So it is very important to do UOA to determine the proper drain intervals as well as to determine a baseline for the condition of your engine which will allow you to monitor the health of your engine.
Vehicles subjected to very short drives or sustained operation in heavy traffic with lots of idling should indeed be serviced more often, just like a race car should. Regular used oil analysis is the best way to determine ideal drain intervals for your driving habits - a good rule of thumb is to change the oil with the TBN, or total base number, is reduced by 50% of the original amount. Another good rule of thumb is when the TBN equals the TAN (which requires additional testing), then it is also time to change the oil.
What is included with every test?
We provide our customers with a test report that provides valuable information on the corrosion, contaminant and physical properties of their lubricant which also includes specific recommendations on the maintenance actions required based on the overall sample condition. This includes:
Spectrochemical Analysis (20 elements for wear metals, additives and contaminants)
Total Base Number