Dealership knowledge is often behind corporate or engineering. Quite typical.

you are correct. Lexus mentions 0-20 or 5-20 synthetic PREFFERED

my sc430 was designed for 5-30 conventional oil.

the 10k change interval on 0-20 synthetic is what my local shop guy goes by. 7,500 miles if you are conservative minded

sorry

So I believed all of you pros and had the 500 mile 5-20 Dino oil changed to 0-20 valvoline synthetic. Will try the 10k change interval. 7,500 maybe. Will monitor the oil use and report if it consumes the new oil...

that is wrong advise on so many levels.

my local shop guys mentioned the political correctness part of the oil change.

i build racing engines since the 60’s. Different crosshatch pattern angles and the grit size used and the metals involved and the rings actual width and material and the piston alloy used and many other details can make an engines optimal for specific kinds of oils.

The metion of the toyota oils having extra ingredients in them matches one of the top NASCAR racers engine increased cam shaft wear.

smog laws are requiring engine oil changes. Some may cause more wear.

the older conventional oils had more additives in them than the new low friction low smog stuff now.

the LS motor was designed in the early 2000’s and as was posted designed around a specific additive package oil.

most conventional oils like the shell rotella I use initially were 50% synthetic even though not labeled.

for sure the previous generation sc430 engine states conventional 5-30 oil in its manual.

five years? later Toyota designed the LS motors.

the 0-20 was not available in bulk originally so Lexus put either 0-20 or 5-20 on the cap.

if I have ring seal issues a help was to dump the synthetic oil and go back to rotella white container for up to 30 hours to reseat the rings. If it did not help a re-ring was the fix.

the idea that my shop has LS 400 cars with 500k miles on them on conventional oils for a large early part of their life’s shows what’s possible.

on the other side Lexus IS in the business of selling new cars. Hard to complain if your car only lasted 175k miles.

if I owned a oil consuming LS car how could I lose if I went to a conventional oil for a while to see?

cylinders may be glazed. Not enough friction?

Versus roll your eyes?

I dumped my 500 mile conventional oil and put in valvoline 0-20 synthetic and will monitor oil use.

next change will be to Toyota oil for the added Moly for wear.

if anyone looks moly can be an abrasive. Maybe helps ring sealing?

Maybe matches the need for a calculated amount of piston ring to cylinder wear needed to insure sealing?

new oils seem to be totally mpg and trace metal smog engineered.

so Lexus added the moly component?

The auto clutch maker for dirt engines requires the non synthetic oil without friction modifiers for their system to work.

exact internal wear on the dirt motors with the 50/50 oil as the full synthetic. Exact.

800 hours on a rod bearing in either setup.

as I mentioned if I were having an oil issue a change to a partially conventional oil for a while then the Toyota moly oil might be worth a test?

several 2000-2010 sc 430’s on this forum with over 300k miles on conventional oils.

sasb turbo’s ran 350k on conventional oils regularly.

Keep in mind when you mention additive packages and different brands of oil, that these formulas they use change, and change big time depending on cost and corporate decisions. Moly was the additive of choice for quite a while (the higher the more popular that oil became). TGMO was famous for it for a long time, but I've seen virgin oil analysis's of it over the last few years and the moly has dropped substantially. Then there are others that claim it's an abrasive and you're better off with sodium. Truth is I don't believe it matters much, many of these additives do multiple things and there's so many of them. Plus as soon as you turn that key and start that engine after an oil change, everything changes. In comes the carbon, the heat, the water, the acid, all the nasty junk that saturates your oil and turns it quickly into something far different than what you poured out of that fancy jug.

And these engines are so different now than the engines you mention in your post, no one is saying you can't use conventional and have success. Just make sure you check that oil and change it, no matter what brand/type you use. 0w20 supposedly has better base stocks than any oil on the market simply because of the high quality base stock required to meet 0w20 viscosity ratings. And there's so many different brands carrying 0w20 - some at outstanding prices - you can get high quality base stocks at a discount if you shop around. I mean supposedly even a Carquest 0w20 contains higher quality base stocks than an Amsoil 5w20 ( not if you're talking about both being 0w20, but if you're comparing a 0w20 to a 5w20 supposedly the value/bargain/bang for the buck is in the 0w20).

Ill tell you what though, 90% of the techs I talk to don't adhere to these long drain intervals one bit. I mean to the man, these guys don't go over 5,000 miles on their oil changes. I was talking to one guy last night - a top tech for Chrysler Jeep Dodge - and he fully believes you shouldn't go over 4,500 miles on any oil, sysnthetic or not. And I hear countless stories of techs feeling the same way. They say, I don't care how improved engine oil is, how many additives do this or that...it's still dirty oil. You still have that junk floating around your engine wearing your rings, stretching your chain, going down your valve guides, getting squishing between your bearings and the filter can't stop it. Think about how dirty that filter gets and that oil just keeps running right through that nasty filter.

I've only met two techs in my life that believe in long oil change intervals, they're both BMW factory reps. And they both tell me how so many BMW engines are being rebuilt at 50,000 miles...how BMW techs overfill the engines with an extra quart of oil, knowing that it'll burn through it so fast that it's necessary to overfill. But they believe in the extended drains, tell me changing oil at 5,000 miles is a waste of time.

Unnaceptable for a car's engine to have those problems at 50,000 miles. BMW considers their cars to be disposable at 100,000 miles, the factory reps told me that is what they're told. That in BMW's mind they do not expect or care if their cars last over 100,000 miles. Their customer base does not keep their cars past that mileage, the used car base does...and they don't cater to them. Ridiculous.