Legender

I do 5 quarts...
on my mom's car with my brother's help, he put in 6 quarts and it was way over the dipstick level.
I immediately pulled a quart out and only use synthetice 5w-30 in her car every 5k miles. I believe 6 quarts is too much and I would not run that much oil in the engine.

Lavrishevo

iTrader: (1)

Oversized oil filters will hold a little more oil too. Does not hurt anything to be a little over or under. You have to loose quarts for the oil light to come on. About 2 - 3 from what I have read. Mobile 1 extended with an oem filter is really performing well. Golden brown at 6500 miles. Going to change it at about 8000k. Even then it's probably early. Dealer recommends 10k on full synthetic.

airchomper

Oh boy this is a can of worms.

First, Toyota presents many conflicting opinions. Toyota/Lexus USA say our transmissions have lifetime fluid, buy everywhere else calls for 60k mile OCIs on the 5 speed, and 100k OCIs on the 6 speed.

Me? I think I know a little bit more about how I use my car than some product planner in California. I probably wouldn't use 0w-20 if I didn't live in Minnesota and didn't have at least 50 sub 10 degree starts per winter. For me, the lower viscosity at 0 degrees is a huge benefit. I probably wouldn't run 20 weight oil if I lived in the desert or the mountains or drove aggressively.

I'd say that my car exceeds 2000 rpms about once a week so I don't really need a ton of high power, high temperature protection.

Secondly, our cars are okay to run on 5w30 dino oil. Most 30 weight dino oil shears to 20 weight viscosity spec eventually, and that's not a problem. Presumably Toyota engineers figured that the engine would have to run on non-fresh oil at some point in its life.

Toyota Japan doesn't have any guidance on our engines beyond 5w-30. However, Lexus sent a chart out to the dealers a while back explaining the back-rated oiling.

You'll see the LSs are rated at 5w-30. But the GS400s/GS430s are backrated to 5w-20 and 0w-20 as well.

There aren't any difference between the engines in the LS4* and GS4*s of the same year (different exhausts and intakes, yes, but the engine is identical). So I can infer that 0w-20 could be appropriate for my car.

All in all, I subscribe to the theory that oil rarely causes engine failures - most of which are related to a lack of lubrication. In a cold start, a thin synthetic oil will always be better than a thicker regular oil. The only issue with low weights is at operating temperature, and I think the consensus is that a 20 weight synthetic oil can hold the power/loads of any 30 weight regular oil.

I have the Toyota techstream tool, and I can tell that you the VVTI works fine with 20 weight Toyota oil. In fact, the VVTI system has oil pressure gauges to make sure the system only engages when there's enough oil pressure for it. So if there was an issue, I would know (there'd be a check engine light / error code) and the system wouldn't deploy so there wouldn't be an issue.

XJSFan

I also live in a cold climate(WI) and I would try a 0W30 but not a 20 weight. Last year my Lexus dealer used a 20 weight during an oil change and I questioned the service manager on this. He looked it up and drained the 20 weight and said he changed it to a 30 weight syn. I have since did an OCI myself with Pennzoil Ultra 5W30 because I did not trust the service manager. I also have a family owned 06 GS430 and I have not seen that it can use a 20 weight. If so great but its strange that a LS430 can not... I always thought it was the exact same engine.

gebo

What's really interesting is how other countries quite consistently recommend heavier weight than we do here in the US. You can go to Castrol website and verify what I'm saying.

Lavrishevo

iTrader: (1)

I don't know about heavier oil and why. Maybe with 300k miles on the engine and if you were starting to use oil.

2007 & 08 LS460's are known to use oil. There are threads about it and switching to 0W-20 has helped some members. There is also an issue with the head and a recall for those models. Anyway, I agree that it probably is OK. Nobody seems to be using it on the 430 though. It is one of the highest rated oils from what I understand. If anything, it would have to do with how the engine is tuned. The LS and GS are tuned individually. There must be a reason why Toyota engineers did not recommend any other weight besides 5W-30.

gebo

I just finished looking through some of the old service records in the car I just bought. At 15K, the dealership used "bulk 5W-40". Now this is the same Lexus dealership that has used 10W-30 and 0W-20 synthetic in the same car. There is not one service record where they used 5W-30 which is what the Owners Manual calls for but used 10W-30 for the majority of the changes. It appears this dealership just used whatever they had in stock. I really don't think it matters a lot as the oil has been changed every 5K and the stick looks honey golden with no junk in oil cap. I just find it interesting.

toddmorr

this is exactly why I don't put that much stock in dealership service quality. The guys there that do this routine work are the least skilled and probably youngest. I just bought an LX470 with nothing but dealer service its whole life....amazing the number of missing bolts and stripped threads on the plastic protective underbody piece you would remove when doing an oil change. Just really **** poor work. Yeah I guess you want a dealer doing TSBs and updating an ECM etc but all the routine stuff.....find a good local tech and they are more than capable, this is not a difficult car to work on. or do it yourself, thats the best of all.