Is Amsoil XLF much worse than Amsoil ASL? I have read both good and bad about XLF after searching. Does anyone have any actual results? Has anyone had an oil analysis with either to say really how well these do against the competition? I am looking at either XLF 5w30 or ASL 5w30.

Also what is the suggested change interval with ASL 5w30 with OEM filter, provided that the driving is mixed city/highway, and isn't spirited/hard driving? I currently change my oil every 6000km (3728 miles). Can the Amsoil synthetic go a lot furter?

Thanks

 

I have used both of these oils in my Z but the 0W-30 Signature Series is the way to go. There is not a better oil on the market but make sure if your going for long drain intervals you use Amsoil's EA oil filters or you need to change your oil filter at least every 6000 miles. I went 8 months on this oil and 11,000+ miles. Amsoil also came out resently with OE with can be used with whatever the owners manual recommendations are. In our case 5000 miles and costs about $5.50 a quart. Hope that helps.

 

Lol, I asked this back in 2008. Sold my G35c since then, but I used the Amsoil XL with no problems at all. Will be purchasing Amsoil OE series for my next car as I like to change my oil every 5 to 6k KM.