This is a 97 Miata that we have owned from new. It is my wife's driver and sees 70% city use and short trips. The only unusual item here is that this is an 11 month sample to get to 4.5K. Oil filter is Denso 150-1011. I had a lifter tick (hydraulic adjusters) when cold with RTS (the previous fill) and this was fixed with the M1 0w-40. The last sample I ran was at 10/2008 and showed a slight coolant leak that prompted me to replace the head gasket. No coolant leak this time! No additives in the oil, I run MMO in every gas fill (93 octane).
OIL M1 0W-40 MILES IN USE 4.58k MILES 192.9k SAMPLE TAKEN 7/20/14 ALUMINUM 3 CHROMIUM 0 IRON 8 COPPER 3 LEAD 1 TIN 1 MOLYBDENUM 68 NICKEL 0 MANGANESE 0 SILVER 0 TITANIUM 0 POTASSIUM 3 BORON 118 SILICON 5 SODIUM 5 CALCIUM 2728 MAGNESIUM 110 PHOSPHORUS 966 ZINC 1082 BARIUM 0 INSOLUBLES 0.2 WATER 0 FUEL <0.5 FLASHPOINT ºF 385 SUS VIS 210ºF 69.3 cSt @ 212ºF 12.77