Because there are no official regulations citing how much “synthetic” must be present in an oil to classify it as “synthetic blend,” the quality differentiation among oils marketed under this term is vast.
Performance attributes of full synthetic base oils can be found in synthetic blend motor oils. Reputable engine oil manufacturers formulate their synthetic blend motor oils with certain percentages of synthetic base oils.
Most synthetic blends are formulated with a combination of premium quality base oils and high-tech synthetic base oils to provide volatility protection, reduce deposits and increase performance.
Basically, all motor oil is formulated with two primary ingredients, base oil and additives. Base oil comprises approximately 80% to 85% of the formulation, so it is easy to see that base oil quality affects motor oil performance.
Full synthetic base oils are made through sophisticated processes and chemical reactions. The molecular structures of the starting compounds are completely altered to produce a fluid with improved properties.
Fixed operations managers and service directors sometimes are left to sort through the marketing jargon, unsure about the quality of the synthetic blend motor oil they are buying. But there are some key differences that they can note to make their buying decisions clearer.
Look first to the NOACK rating on your synthetic blend.
A synthetic blend oil with a low NOACK rating will provide superior volatility protection.
NOACK is the industry accepted measure of oil volatility protection — the qualitative indicator of oil consumption through “burn off” or vaporization during engine operation.
One of the attributes of synthetic base oils is low volatility. The base oil has less of a tendency to evaporate in the high-heat environment of an operating engine. Lower volatility reduces oil consumption and also assists in the control of deposits.
The industry's most stringent standard for the ACEA NOACK Volatility Test is 13%, while the GF-3 and GF-4 limit on NOACK is 15%.
So the lower the NOACK volatility, the better volatility protection you're providing to your customers' vehicles.
Though not all manufacturers list their NOACK measurements, service managers can always ask. Remember, the lower the better.
There is another benchmark for considering the equality of all synthetic blend oils. Look to oil standards.
A lubricant manufacturer engineering a blended synthetic oil that meets the American Petroleum Institute oil standards in America, the European Automotive Manufacturers Association in Europe and the International Lubricant Standardization and Approval Committee overall is meeting the engine protection requirements as well as the shear stability and stay-in-grade requirements for that synthetic blend oil.
When you've done your homework, you'll be confident in the knowledge that the synthetic blend your dealership's service department is offering will provide lower volatility, better deposit control and a more shear stable formulation to your customers.
Kevin McGee is market space manager-new car dealers for BP Lubricants Americas.