Written By: Corey Foy



The GF-6 & API SP Specifications were ready for licensing on May 1, 2020 with mandatory industry-wide implementation scheduled to take place over the following 12 months. These specifications were designed to meet performance demands of modern engines, while delivering higher levels of wear and deposit protection than previous categories.


In additional to added fuel economy benefits and wear protection, the GF-6 specification includes testing specifically to address the problem of low-speed pre-ignition (LSPI), which can occur in turbocharged engines and cause severe damage.


So what is Low-Speed Pre-Ignition (LSPI)?

LSPI refers to an abnormal, premature engine combustion event at low speeds, in which the fuel to air mixture ignites before intended, causing excessive pressure inside engine cylinders. The higher power density of turbocharged engines makes them vulnerable to LSPI.  In minor cases, LSPI can cause engine “knocking” noises, but more severe cases can cause permanent damage to cylinder walls, piston rings, connecting rods, and spark plugs. SN+ was originally implemented as a stop-gap which GF-6 test standards were in development.


In addition to the more rigorous testing requirements, ISLAC GF-6 will have two subcategories A and B. GF-6A oils will be backwards compatible with all previous engine technology (Just as CK-4 is) and carry the recognizable API “Starburst” certification mark, whereas GF-6B covers only one grade of oil, 0W-16, and is intended strictly for newer turbocharged engines.  GF-6B is not backwards compatible and certified oils will have a new API “Shield” certification mark.

API’s newest service category is SP.  ILSAC GF-6 applies to the fuel efficient viscosity grades above, while API SP will cover the heavier viscosity grades like 10W40 and 5W40.  This category is fully backwards compatible with the previous API categories, including API SN+, SN, SM, etc.


So how does this affect you? Typically if you have a new vehicle you will need an ILSAC GF-6 oil to ensure you’re receiving the proper level of protection for your vehicle.  If you have an older vehicle, you will still receive the wear protection and fuel economy benefits of using a GF-6 backwards compatible oil.