Difference between GF-5 and GF-6 engine oil?

[KatherineLee]

Engine oil GF-5 has a viscosity grade of 1000, while GF-6 has a viscosity grade of 5000, with the difference lying in their varying viscosity grades. Compared to ILSAC GF-5, the GF-6 specification offers numerous improvements. It maintains fuel economy and enhances engine durability, wear protection, prevention of low-speed pre-ignition (LSPI), reduction of timing chain wear, turbocharger deposit control, and sludge reduction. Stringent emission and fuel economy regulations drive changes in passenger car hardware system design and engine operating conditions, demanding higher performance from lubricants, including new dimensions of hardware protection. This means OEMs require more robust engine oils. These factors, along with the discontinuation of some current engine tests, are key drivers behind the development of the ILSAC GF-6 specification.

[VonNicole]

I was just talking about this the other day while helping my neighbor check his car. Simply put, GF-6 is an upgraded version of GF-5. Having driven a taxi for twenty years, I know best—GF-6 specifically enhances low-speed protection. Many new turbocharged cars nowadays tend to have issues at low speeds, and the new oil is designed to address this. Additionally, GF-6 is divided into two categories, A and B. For example, low-viscosity oils like GF-6B are particularly suitable for hybrid vehicles—older standards like GF-5 didn’t even have such specifications. More flexible viscosity options are another advantage, though older cars can still use GF-5 without any issues. The most practical benefit is GF-6’s stronger cleaning capability, reducing carbon deposits by nearly 30%. I’ve personally seen an engine with 80,000 kilometers on it taken apart, and the pistons were impressively clean. If you’re buying a new car, it’s a safe bet to go for oil with GF-6 certification.

[LucyFitz]

Last time at the car club sharing session, I mentioned the engine oil standards. The GF-6 has three major improvements: first, better fuel economy, with actual tests showing 2% fuel savings under the same road conditions; second, more anti-wear additives added, especially to protect the chain mechanism of small-displacement turbocharged engines; third, comprehensive upgrades in environmental parameters, with particulate emissions being 15% lower than GF-5. A key detail is that GF-6 specifically prevents low-speed pre-ignition, which is particularly important for new cars equipped with auto start-stop functions. However, there are still many GF-5 stocks on the market at cheaper prices, and if you're driving a five-year-old car, using GF-5 is still perfectly fine.

[Lola]

Just finished changing the oil for my car. The GF-6 standard shows significant improvements over the old one. The most noticeable difference is the smoother cold starts—the engine stabilizes instantly in the morning. The new standard oil has better high-temperature oxidation resistance, so it doesn’t thicken as easily during long drives. The most surprising improvement is the noise reduction—engine noise has decreased by nearly a quarter. Nowadays, 4S shops use GF-6 grade oil for maintenance, with the Roman numeral VI prominently printed on the packaging. Just be careful not to buy counterfeit products—it’s best to purchase from authorized channels with API certification.