Which Oil To Use?

[jmwgomz]

Hey guys, I have a 1991 LS400 with 175,000 miles on it. I want to do my own oil changes but am not sure which oil to use. I know what Lexus recommends but I believe that mileage is a factor in the decision as well.

I would greatly appreciate your thoughts on this matter.

[silvermate]

do a search this his been talked about a million times

[jmwgomz]

Hmm, after searching around on this forum it seems that the general concensus is Mobi 1 synthetic. I hope there is nothing wrong with any of my seals.

Since the car has such a high mileage, I think that I will probably go with 10w-30. I know that the following oils have been used in the car before:

Castrol GTX 10w-30

Castrol GTX 20w-50

Castrol Syntec 10w-40

Do you guys see a problem with any of this? Your input would be greatly appreciated as I hope to change the oil tomorrow morning.

[SRK]

The oil filler cap says 5W-30, and that will be fine for the life of the engine.

For sure 20W-50 is an obsolete oil viscosity except for clapped out English sports cars, and should be avoided. Even highway semi-tractors use nothing thicker than 15W-40. Stick with 5W-30.

[jmwgomz]

I don't think that the 20w-50 was used more than once. And I think it was in the engine for about 2.5 months (2,700 miles). Do you think this could hve caused any damage. I have not noticed any problems with the car. It runs great.

[SRK]

Probably no damage at all, and not worth worrying about. Just use the correct oil from now on, and rack up the miles and enjoy the car.

[jmwgomz]

Nice! Thanks a lot for your input.