No conocía bases que dieran W30, pero esto dice Toyota:
Genuine Toyota Motor Oil
Formulated with a special additive package that helps protect Toyota metal and gasket surfaces from corrosion, prevents foaming and maintains the proper application of oil on cylinder walls.
• Available in 5W-30, 10W-30 and 10W-40 grades
• Four-point depressants maintain fluidity in cold climates
• Viscosity index improvers stabilize viscosity levels for a wide range of operating temperatures
Synthetic Motor Oil
Many new Toyota models are certified for a new, zero weight synthetic lubrication standard, or 0W-20. This lower viscosity oil pumps better when cold, yet provides uniform lubrication, reduced friction and better overall efficiency than conventional engine oil.
• Improves fuel economy
• Improved thermal stability
• Longer oil change intervals
Bueno, como indica Toyota, hay unos aceites que llama "Genuine Toyota Motor Oil" en viscosidades 5W/30, 10W/30 y 10W/40 y otro que llama "Synthetic Motor Oil" en viscosidad 0W/20. Puede entenderse que los primeros no serían sintéticos.