OW-16 vs 0W-20 viscosity specs - does it really matter.

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What instigated this thread is I am debating dumping the new 0W-16 out of my Toyota and replacing it with 0W-20. The 0W-16 is new. I took the car to the dealer - feel obligated as its still in warranty - and they changed the oil for free - work order and window sticker say 0w-16 which is what the manual calls for.

In reviewing the J300 specs, there is quite a bit of overlap in the spec, and HTHS isn't that far apart?

I also have no idea what they put in - likely the cheapest crap around. However in looking at the M1 Advanced Fuel Economy for the 16 vs 20 weight, there like 7.2 Vs 8.2 KV@100C?

So do I dump it and put in 0w-20?

Side question, if I do - do I change the filter - its a new OEM filter - so I am thinking not on that part.


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Honestly, I would not dump it. I ran a 10K OCI of Castrol Edge 0W-16 in my Gladiator Pentastar 3.6L that specs 0W-20. Submitted a oil sample to Blackstone and listed it as a 0W-20 sample and the report came back with a 7.7 cSt for the viscosity which was well withing spec of a 0W-20 grade. Nothing abnormal on reported values either.

Current fil is a 60% 0W-16 and 40% 0W-20 of Castrol Edge. Expect no problems with this either but that will have used up all the extra 0W-16 I had laying around and will go back to just 0W-20 going forward.
 
Does the ECU controlled oil pump care? Probably.
I have run 0w-20 before already. The manual for the same engine from Australia says I can use anything from 0w-16 to 15w-40. The US manual says I can use 0w-20 in a pinch. Not concerned about any of that at all. Just thinking about the real world difference between 16 and 20 weights - if any at all?
 
I have run 0w-20 before already. The manual for the same engine from Australia says I can use anything from 0w-16 to 15w-40. The US manual says I can use 0w-20 in a pinch. Not concerned about any of that at all. Just thinking about the real world difference between 16 and 20 weights - if any at all?
Other parts of the world may have a different ECU programming to allow the heavier weights.

The real world difference is fuel economy, a small maybe fractional percent difference of fuel economy. If you stick to TGMO oil, the wear difference is probably negligible, since TGMO has a high boron and moly additive package.

But when you stray away from TGMO to so-called "Better" oil say Mobil 1 Advanced Fuel economy, the basestock may be better, but the additive package won't be as good.

If you went to HPL, which their additive package is very stout, you probably won't notice much of a difference between 0w20 and 0w16 also.
 
Does the ECU controlled oil pump care? Probably.
Other parts of the world may have a different ECU programming to allow the heavier weights.
What parameters does the ECU control in terms of the PD pump? Think this has been hashed out before, and found that the pump simply controls the pump output as a function of engine RPM. So in that case, the engine would still be getting the same programed oil flow vs RPM regardless of the oil viscosity.
 
I would leave it in for something like half your normal OCI; may as well, it's fresh oil and specced by Toyota. Then change to 0W20, a little more viscosity never hurts, and it's unlikely you would ever notice any reduction in fuel economy.
 
The safe choice is to use 0W-20. It's higher HTHS of 2.6 should give you a long engine life.
0W-16 has HTHS of 2.3, which is below the normally accepted HTHS for adequate engine protection.

In my opinion, it's better to use a tried and true viscosity than a new viscosity whose long term engine wear is unknown.
 
Other parts of the world may have a different ECU programming to allow the heavier weights.
Really? How do you know?

The real world difference is fuel economy, a small maybe fractional percent difference of fuel economy. If you stick to TGMO oil, the wear difference is probably negligible, since TGMO has a high boron and moly additive package.

But when you stray away from TGMO to so-called "Better" oil say Mobil 1 Advanced Fuel economy, the basestock may be better, but the additive package won't be as good.
How did you come up with these assumptions? How do you know that the additive package in Mobil 1 is not "as good" as TGMO? Can you please share some test data to support your claim?
 
not much programming needed to run an oil pump: vary a PWM signal to keep oil pressure around the target. and in some cases, like high rpm or right after start-up it's "give it all she's got"
 
I also have no idea what they put in - likely the cheapest crap around.

Who is making crappy 0W-16? It’s not like they’re tossing in a bottle of gas station group 2 oil.

I would personally leave the oil in there and not give it another thought. If this engine diluted oil and I did a lot of hard driving I might consider a higher viscosity, but even then I would tend to trust the OEM until proven otherwise.

With that said, I know there are things that just bug me and no matter how logical and rational the counter argument is (I’m not saying I’m the rational one here or anything, just in general), if I want something done a certain way and it doesn’t hurt anything, I just do it. It doesn’t hurt anything to put a 0W-20 in there while you figure it out. Well; it costs money.

Regardless, leave the filter. There is no reason to change that out. The small amount of thinner oil will be diluted into new oil and be just a blip.
 
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