I've been saving this one for "Dr T"
Oil....Amsoil 10w-30,"ATM"/Amsoil 20w-50, "TRO"
Miles on engine, 167,000/145,000
Date of test ....2/21/2000, 10/4/1998
Miles on oil.....12,000/12,000
Makeup Oil .......1.0 qt/0.0 qt
Water............0.1%/
Fuel.............
TBN/ASTM D-2896...5.9/8.2
Wear Metals:
Fe, 62 ppm/20 ppm
Cr, 5 ppm/1 ppm
Pb, 15 ppm/7 ppm
Cu, 42 ppm/15 ppm
Sn, 1 ppm/0 ppm
Al, 14 ppm/6 ppm
Ni, 1 ppm/0 ppm
Silicon, 16 ppm/5 ppm
Oil Additives:
Boron, 16 ppm/39 ppm
Mg, 392 ppm/365 ppm
Ca, 3125 ppm/3020 ppm
P, 1260 ppm/978 ppm
Zn,1531 ppm/1280 ppm
Note: This is the previous 10w-30 chemistry that was changed in mid 2002. I believe the S2000, 20w-50 has been reformulated two times since 1998 ....

Oil....Amsoil 10w-30,"ATM"/Amsoil 20w-50, "TRO"
Miles on engine, 167,000/145,000
Date of test ....2/21/2000, 10/4/1998
Miles on oil.....12,000/12,000
Makeup Oil .......1.0 qt/0.0 qt
Water............0.1%/
Fuel.............
TBN/ASTM D-2896...5.9/8.2
Wear Metals:
Fe, 62 ppm/20 ppm
Cr, 5 ppm/1 ppm
Pb, 15 ppm/7 ppm
Cu, 42 ppm/15 ppm
Sn, 1 ppm/0 ppm
Al, 14 ppm/6 ppm
Ni, 1 ppm/0 ppm
Silicon, 16 ppm/5 ppm
Oil Additives:
Boron, 16 ppm/39 ppm
Mg, 392 ppm/365 ppm
Ca, 3125 ppm/3020 ppm
P, 1260 ppm/978 ppm
Zn,1531 ppm/1280 ppm
Note: This is the previous 10w-30 chemistry that was changed in mid 2002. I believe the S2000, 20w-50 has been reformulated two times since 1998 ....