Ls400 (celsior) Oil Grades ? ?

[xxx-large]

MAY change Dad's oil (&filter) straight away, even though they

said they'd done it............

Any 'words-of-wisdom' about too high / too low oil grades for the 4.0 ?

I'm thinking ~ Fully/Semi Synth' ~ 10/40, 15/50 or is 5/40 OK ? ?

FatS.

[budcook]

What does the owner's manual say? I suspect that Lexus will tell you to use some type of 30 weight oil but IMHO, the perfect oil would be the same oil that was designed for European high performance engines and which is specified by both Mercedes and Porsche.

It's 0W-40 Mobil 1 and can be had at Autozone if you are in the U.S. It's not cheap and you can get a better deal on 15W-50 Mobil 1 at WalMarts in the 5 quart containers. However, I don't think Toyota/Lexus would recommend that high a viscosity.

I think by now that most experts agree that using a true synthetic is worth it, especially when you are talking about a gem of an engine like the Lexus V8's.

[ColinBarber]

MB, BMW, VAG etc use fully synthetic to extend oil change intervals. Normally around 20,000miles. Lexus still change at 10,000miles and do not state a synthetic oil is required. Part synthetic will be fine.

I would say a 10/30, 10/40 would be fine. No need to going as high as 50 nor as low as a 0.

In the UK 5W-30 is the preferred viscosity but 10W-30 and 15W-40 are also recommended.

[budcook]

The Mercedes FSS system maximums are set to 10,000 miles or two years, whichever comes first. BMW's average about 10K in their system. It's not 20K miles. Mercedes owners were using synthetic oils long before the extended oil change intervals came about.

The Flexible Service System (FSS) has a different name in some other markets.

If anyone doubts the benefits of synthetic oils, they need only know that Toyota caused oil to gel in their V6's by increasing the oil temps in the heads (smaller passages) to reduce emissions. Petroleum based oils gelled if not changed frequently. Synthetic oils did not. Toyota has sinced opened up the passages to fix the problem.

[ColinBarber]

Petroleum based oils gelled if not changed frequently.

This is the point, change your oil on schedule.

As for BMW or VAG oil change frequency, here in the UK they run much longer than 10k. I know several people with Audis and they, if the top oil is used, get around 22k miles between services and they are engines with turbos which are much more hard on oil.