There seems to be different mixtures. Which Mobil 1 formula do I use? There is a extreme formula, and there are others for example 15-50 (which is said to be used in high-tech imported cars). Can I just pick any one of these? Any suggestions? Thanks.

-Andy

 

Andy - Why not stay with the viscosity that Lexus specifies for use in the GS ( 5W-30 )? Just don't bother asking them because they don't seem to be fans of synthetic oils anyway! Above this, it really depends on how/where U drive & your maintenance schedule that U adhere to. In colder climates, the 5W-40 will flow faster at first startup in the morning while those who live in a more warm climate might benefit from higher viscosities. If U drive hard, then obviously the engine sees higher temps than most so the thicker oil would be a good choice again. Haven't seen the ads on this "Extreme" Mobil One so I can't advise one way or another on it. Maybe it's designed for longer change intervals? Just stay with a good multi-viscosity range like the aforementioned 5W-30 or 15W-40 & U'll cover all the bases!