robchap83

Hey guys, new to the forum, I searched around and didnt find any info on this, but basically I recently purchased a 2010 GS450 H. According to Lexusdrivers.com mine is due for an oil change, under the hood and in the manual 5w30 is recommended but the last oil change from the dealer (windshield sticker) indicates that 0w20 was used. Anyways, I put the Mobil 1 0w20 fuel efficiency oil in there today. Tell me I dont have to change it again lol And why did the dealer switch from 5w30 to 0w20 and additionally if they are recommending 0w20 why did they not change the fill cap accordingly on the last oil change, or put a correction in the manual? I bought it from a Lexus dealer...

tghw

0w oil is too thin for these engines. Toyota recommends 5w30 and that is the minimum that should be used to avoid excessive wear. . It's better/safer to go the other way and run 10w30 for added protection. Personally I would drain the 0w and replace it with at least the factory recommeded weight oil.

I just noticed your location. You also live in the desert which makes it even worse because heat thins the 0w out even more. Considering your location, I would run 10w30 and definitely dump the 0w oil..

robchap83

That's exactly what I was thinking! But why would the DEALER put that oil in there, was looking for some TSBs or something to back it up but didnt find anything specific.

tghw

No idea why a dealer would do that, but it was a dumb move.

SILENTM

The "W" means winter this is how thick (viscosity) the oil is when cold. Worry more about the viscosity when engine is at operating temp, if you dont live in cold/ freezing climate 0w or 5w is fine any thicker could make oil flowing to the upper parts of the engine on start up slower there for you cold get chatter from the variable valve cams . The 20 index rating is more for fuel economy and has been tested to be safe against engine wear for toyota/ lexus 2006 and higher per tsb, 30 will provide slightly more protection. Being that your in a hot climate 5w30 is good for the summer high temps but using 0w20 is fine for the cooler season. Obviously the manufacturer have done extensive testing to suggest being able to use lower viscosity oil. Hope this gives you a little more insight into deciding what oil to use in the future, (just let them know before they do the oil change) otherwise they will use 0w20/ 5w20 per the TSB for better fuel economy and reduce emission.

gs350fan

I don't believe Toyota never backspecd anything (unlike Ford). Even Ford had exceptions for certain cars that must have 5W30.

But the newer GS take 0W20, I don't know, they could have a different pump. They also specify a much longer OCI.

Honestly, a synthetic oil like Mobil 1 is fine, these cars were speced for dino oil. Unless you are doing racing or severe service, its is probably ok, only thing is the very hot climate you are in, but for daily driving it should still suffice.

Your engine won't self destruct buy if you want peace of mind change it. Maybe drain off 3 qts and replace with M1 10-30, use the remainder next time.

tghw

Ow20 oil turns into water-thin viscosity in warm weather. G3 engine bearings and clearances were not designed to use oil that thin. The newer Lexus engines were designed to handle the thinner oil. It very well could lower oil pressure and increase bearing wear over time. Will it kill an engine? Probably not, but it could reduce the overall life. Oil is cheap relatively speaking, engine repair is not. If it were me, I'd change the oil. It's ultimately up to the owner to decide what gives him peace of mind.

robchap83

Just a quick update, I called the servicing dealer and asked why there is a discrepancy? And they transferred me to the service department, who ran my vin thru their system and said the technician put 5w30 in it and that she did not know why the windshield sticker said 0w20. So itll be coming out next weekend, I'll just baby it to work and back until then.
thanks for the replies...