I bought a 2007 base model LS 460 one year ago with 100k miles on the odometer. I immediately had the oil changed at the nearest Toyota dealer. They used Mobil 1, 5-20 viscosity.
Historical note: This is the same oil I have always used in my 2006 Sienna which now has 199k on the odo and uses no oil at all. I have always changed oil at 10k intervals and had the drained oil tested a few times to make sure that was OK.

A few weeks ago, I had the Mobil 1 in the Lexus changed after driving 8500 miles on it. During that time I had to add two more quarts and was about ready to add a third. I estimated that the Lexus used about one quart every 2500-3000 miles at a pretty steady rate. No leaks or visible smoke.

The local independent service shop filled the Lexus with Valvoline full synthetic, 0-20 viscosity.

I sent in a sample of the used Mobil 1 to Blackstone Labs. They said the oil was still in excellent condition and that I could try going 11,000 miles next time. No sign of any unusual engine wear.

Now here's the strange part... We drove the Lexus for two weeks on a 3500 mile road trip and found oil consumption is now near zero, maybe a tenth of a quart. I have no idea why oil consumption would decrease like that. Any ideas?

 

My only guess points to Lexus changing their recommendation from 5w-20 to 0w-20. There was info in some thread about Lexus telling that to dealership service departments. I don't know why but later models are ow-20 only.

 

The high detergent content of the Mobil 1 combined with long highway trips cleaned and un-stuck the oil rings.

 

That makes sense to me. The LS was mostly used for long highway trips during the 8500 miles with Mobil 1.

 

Honesty some oils use less than others. That’s what I’ve found over the years.

But I wouldn’t trust laboratory tests telling you to take it to 11,000 miles next time, based off the fact that you added two quarts and replenished the additive pack, skewing test results.

 

I thought about that myself. It might be helpful to point out that they told me the same thing about my Sienna which never had any oil added. I decided to stick with 10,000 mile changes for the Sienna simply because it was easier to keep track. I got it synchronized with the odometer so that I was changing at 150k, 160k, etc....

Now that I have two vehicles, each is used less than 10K per year, so I might go to a once a year change interval.