UOA @12k miles, synthetc vs. regular oil

tranceformer

My Z is now at ~12k miles. Until about 5,500 miles I would just go to the dealership for the standard oil changes at 3k miles or less.

I was curious to see the difference between using synthetic & regular oil. Although I think the results are somewhat skewed because of the engine still breaking in. Either way I'm pleased with the oil/filter combo, it's keeping my motor healthy. I used the same combo again with the last oil change, but I might try something else off the shelf next time. Maybe Pennzoil Platinum and K&N filter or PP w/ a Purolator filter.

1st UOA
10/2009
regular oil & OEM oil filter at the dealership
~3k miles & ~3 months of use (NJ)
80% city / 20% highway

2nd UOA
3/2010
Castrol Syntec 5w-30
K&N oil filter
~3k miles & ~6 months of use (NJ)
25% city / 75% highway

3rd UOA
5/2010
Castrol Syntec 5w-30
K&N oil filter
~3k miles & ~2 months of use (FL)
25% city / 75% highway
Note: replaced air filters with OEM at about 13,800 miles.

4th UOA
7/2010
Castrol Syntec 0w-30 aka "German Castrol"
4200 miles & months of use
25% city / 75% highway
~30 passes at the 1/4 drag strip

__________________
Ray
2009 370Z Base Sport 6MT / 12.860 @ 109.09mph / 1.921 60ft / street tires
official 1/4 mile track times