Stebbi - I'm a synthetic oil nut, worked on engines for 50 years (career was in technology though), and been using nothing but synthetics since
1977 in all my vehicles & newer motorcycles (NOT in my classic old Triumph's). Started with Mobil 1, but last 5 years use only Amsoil. Clearly
proven to be the best of the synthetics. Use it and you don't need any questionable additives. And you'll get 300k trouble-free miles out of your Lexus engine.....
IMHO.
gatornapper
'09 GS350 AWD w/Nav, silver
'03 GS300 (sold to realtor daughter), silver
'08 Porsche Cayman (just traded, looking for an '09 S model)
'09 Harley "Screamin' Eagle" CVO Road Glide FLTRSE3, '07 Harley Wide Glide FXDWG, Stage II,
'71 Triumph Trophy 500 T100C, '72 Triumph Bonneville T120V, '73 Triumph Trident T150V