ILSAC GF5 vs GF6 for detonation

[Whammo]

Will GF 6 help with engine detonation more than GF5 or do these specs (or oil in general) have no relation to that?

 

[Nessism1]

I think the LSPI test is the same for both.

 

[twX]

I think the LSPI test is the same for both.

It depends. GF-5 covers both API SN and SN+. API SN had no LSPI test. SN+ was introduced as a stopgap measure to add an LSPI test to API SN. Auto manufacturers weren't happy with how many of their engines were blowing up while still on warranty, and didn't want to wait for the next major update in oil standards.

The LSPI test for API SP / GF-6 is basically the same as SN+, but with some minor changes. API SQ / GF-7 has a more stringent LSPI test than API SP.

 

[twX]

Will GF 6 help with engine detonation more than GF5 or do these specs (or oil in general) have no relation to that?

If the engine is both turbocharged and direct injected, then the specs do matter. These engines are prone to low speed pre-ignition (LSPI), which is a form of pre-ignition unique to these engines (which often results in detonation).

Port injection engines and naturally aspirated direct injection engines can also experience detonation, but for those engines the mechanisms are not the same, the oil formulation probably doesn't matter, and it's it isn't a common cause of engine failure anyway.