2.0t Used Oil Analysis

I opted to do oil analysis through blackstone labs to establish a proper oil change interval suited for my driving style and conditions. My first UOA was done in Sept 2006, using Castrol 0w30 (aka "GC"). While iron wear was relatively high for my tastes the oil stayed mostly in grade despite significant fuel dilution.



The next oil analysis I did was in Jan of 2007, using the newly reformulated Amsoil 5w40 AFL. Wear improved significantly, but flashpoint and viscosity suffered much more than with the GC. Although fuel dilution increased from the last sample, I do not believe it is an issue, based on the amount of time I let the car idle during the winter.


Since this last oil change, I have switched back to the Green GC based on the better PAO/Ester basestock. The thinner weight 0w30 GC should improve overall MPG as well as reduce the amount of time it will take to bring the oil up to temperature.