Originally Posted by ronkelley

Where is it "well known" that you must use the same blend or viscosity? Mixing two different viscosities of the same brand, blend, and type of oil should just change the compounds only slightly.

Originally Posted by LeX2K

Tests have been done by mixing 5-6 different oils, there was nothing wrong with the oil it performed well. Not like the best out there but certainly didn't create some horrible brew that will ruin your engine.

Originally Posted by GNS

My car came with 0W-20 as factory fill. I ran that for the break in period and for a couple of oil changes after that, then switched to a quality synthetic 5W-30. It's fine to switch over, you're not mixing large quantities of the old oil with the new fill, and it'll gradually be completely replaced by the 5W-30 after a couple more of those changes.

As for the viscosity, I won't put 0W-20 in my engine because I know that the 2GR-FSE was the same engine between the 2013 and 2014 models, but the owner manuals for both cars specify different viscosities (2013 5W-30, 2014 0W-20) right around the same time that fuel economy regulations changed. My own 2GR-FKS is an evolution of the 2GR-FSE, and still uses the same oil pump, same passages, etc.

I have also looked at the Australian owner manuals for my model (2019 AWD) and those seem to have more of an emphasis on proper maintenance than the North American manuals. For instance, they still have maintenance schedules and specify replacement of the transmission fluid at around 100k km, while NA manuals don't even say anything about that part.

Anyways, Australian manuals specify a much wider range of oils, I think even down to the 20W ones, and basically say 'use your judgement and choose the one that suits your temperature range'. Since it's not cold year round in Ontario Canada, and 5W-30 is still fine even when it's -30c, I can only conclude that the recommendation of 0W-20 is mostly for fuel economy and to streamline the oil recommendations for all of Canada including the regions that DO see lower than -30c in winter (ie. Calgary, Winnipeg, Nunavut, etc).

Originally Posted by LaZeR

If you RE-read ALL my post(s) said "i "THINK" (key word) it's fairly well known that different viscosities &/or blends should NOT be mixed. I didn't say ""MUST" use the same blend or viscosity".

[You're being picky here. When one says "think", they're normally saying that they believe something is true. Considering the rest of your post, this shows that you believe it is wrong to mix oil--hense, you seemingly believed you should (i.e.: must) not mix oils. And the post you are replying to is asking about switching to a different viscosity for which you reply "...it's OK [color=#222222]to top up with the same viscosity." This would indicate that it is something that "should" be done, not that you "think" it might be harmful.]

BUT... are you guys saying that you deliberately & regularly MIX different blends / brands / viscosities on oil changes, or topping up?

[Who here said that????? However, the links I posted give you some indication that some "experts" in the field have pretty loose standards as to what will work and whether it will harm an engine.]

If your answer is "NO" then doesn't common sense dictate "AVOID doing this"? We're talkin bout Lexus Luxury sports cars which deserve the highest level of service...

[Common sense does not show that at all. Just as you can fill your tires with nitrogen since it can be considered "better air", but is that necessary just because we have an upgraded Toyota? Or only use Top Tier gas? Or only nanofiber air filters? These are not Rolls Royces.]

LOL

Originally Posted by LaZeR

Got some $$ credits with the Lexus dealership here so been going there for the last couple oil changes. For the past few years they always use Pennzoil Platinum Full Synthetic from BULK - viscosity 0W-20 - but it also comes in 0W-16, 5W-20, 5W-30, 10W-30.

On another note, "Service" ain't too shabby coz they do an inspection on lotsa stuff saving you time from doing it yourself, and know for certain that NOT ALL Lexus dealerships offer a FREE car wash!! lol

Originally Posted by ronkelley

I always have to pass on the "free" car washes since they're not always so gentle and I can easily lose my hand painted pin stripes.

Originally Posted by LaZeR

Ya well due to almost full PPF felt compelled to inquire if "touchless"... the service advisor advised "soft cloth" so wth not.

Originally Posted by ronkelley

... Anyway, I just don't drive unless necessary when the weather is bad so I don't have to wash too often.