What’s With the Oil Viscocity.

I just came up from years of and multiple 1st gens. And years, since the 70’s, of building engines and cars. Looked under the hood of my new 2019 and thought it was a misprint. There’s a sticker saying this engine specifies 0-20w oil. 0 is water. Does anyone else have a problem with this weight? Or am just an old codger that things oil should be slippery?

 

Viscosity is resistance to flow and has nothing to do with whether or not the oil is ‘slippery’.

 

Search out some UOA threads here and enjoy some good reading.

 

The 0 just means it doesn’t thicken as much when it cools. It’s a winter rating. The operating temp viscosity is 20 which is very common in today’s modern engines.

 

You said it right there, the oil is water. Like noticably at that.

I believe it has been said by Toyota themselves that 0-20 is implemented purely to obtain better fuel economy. If I owned a 3rd gen I would be running 5-30 and would be changing the oil well below the recommended interval. I've changed the oil on enough 0-20 cars going to or past 10K miles whose engine internals look like carboned up garbage due to running those intervals. That's just me though.

Another oil thread. Great. Hahaha.

 

I've heard similar suspicions of trading engine longevity for fuel mileage before, and I hate to say that it seems possible. No good way for us to test it though.

 

Actually, do they still have the chart in the manual stating which oil to use for which temperature?

 

Except for the fact that’s there been no real correlation of engine being less reliable or failing sooner with the transition to 0w-20. Look at the Prius’, Camry, etc that are still logging hundred of thousands of miles like champs. I know a guy who has 2 2016 V6 Tacomas and he runs the cheapest 0w-20 available, Supertech from Walmart. He’s nearing 400k miles between the 2 trucks and has had no issues. He also hauls and tows on a daily basis in Arizona/Nevada/Cali and runs around 7500 mile intervals. Basically keep it full with the specified 0w-20 and drive it.

As for running 5w-30. Have fun potentially messing with your vvti system which is sensitive to oil pressure and flow rates, meaning it’s specified to function properly off of 0w-20. Trying to out-engineer the engineers leads to visits to the service department. Owners manual tells you everything you need to know.

 

Had a '19 Camry with the 2.5L engine in the shop recently. Sticker under the hood stated 0W16 oil !

 

Yup. As does every OM.

 

In my time as a tech I have never seen more vehicles destroying main crankshaft bearings, blowing head gaskets, and burning oil than 0-20 oil vehicles. To me the proof has been over time. Others will take the Blackstone lab chart and throw it in your face. I guess you have to take these threads with a grain of salt for what they are worth.

It's funny you talk about Prius because the 3rd gens which use 0-20 pop head gaskets left and right after 150K due to the fact there is low oil pressure because they wait so long in between maintenance intervals and the oil burns off causing low oil levels ultimately resulting in rough idles and random or cylinder specific misfires. If you don't believe me you can meander into their forums and see for yourself how many head gasket issues those guys get. We had two head gasket Priuses caused by low oil in the same week once actually.

 

Hmm well your testimony is the opposite of mine. Been running it for years now without any engine related issues. None of those issues mentioned have even been slightly a general issue with the Tacoma. As for the Prius oil burning issue, it has been shown that changing oil weights had no adverse effect on stopping or slowing the oil burn, so you can try and blame the oil weight, but it’s already been shown to be related to poor build quality out of that series of engine, the 1.8 2ZR. In some nations it was still specced for 5w-30 and was having the same exact issues of consumption. And also a bit of it falls on the customer. If you want to run 10k intervals without checking the oil at any point, your gambling. If you allow it to run low than that’s on you as a customer. So it’s a mix of lack of proper care/mx and poor engine quality/design.

 

The fun part here is we have lots of anecdotes, lots of variables and very little statistical data. The fail of most internet discussion.

The reason I was asking about the oil chart in the manual is to see what it says. If it says there is another, heavier, oil that is okay to use at all temperature ranges, then i would run that.

 

The fact that we have oil threads about brand and weights but none about consumption is pretty good evidence. There are also UOAs posted by a few folks including @Woodrow F Call who has been kind enough to post them for every interval showing that wear metals are negligible and the additive package is going strong at 10k.

The answer is in your OM, either in your glove box or in PDF form at Toyota.com.

 

I could actually agree with that. It is a combination of things exacerbating the issue. Poor build quality lack of maintenance and staying on top of your fluid levels are all contributors.

I still do not like what I have seen on the 0-20 high maintenance intervals cars though. Absolutely disgusting internals.

 

From the 2019 tacoma manual:




The interesting part is they say you can use 5w-20 in a pinch, but not very long. Makes me think that there is some specific reason why 0w-20 is required beyond just fuel economy.


There's another possibility here too - @12TRDTacoma could be seeing oil related failures due to the 0w-20, but there could also be *other* oil related failures from using another oil as suggested by @StillNoPickles. They don't have to be the same failures.


As for me, mine calls for 5w-30. So I'll just run that

 

Hell if you’ve got the 2.7 in your 2000, you could run that thing for a million miles on molasses!

 

That sure would smell interesting

It is the 2.7, and it's just 500 miles short of 200,000 and the dipstick level does not move between oil changes. Could not be more pleased about that, burning oil is a pet peeve of mine.

 

The reason it may say that you can run 5-20 in a pinch is because the oil pressure sending unit may not like seeing oil thicker than water. If it does it may think there is a reduction in oil pressure and throw false codes like incorrect oil pressure, or no oil pressure and you may see incorrect oil pressure readings on the digital cluster (if it has that function on 3rd gens).

Of course it may not and they may just be writing that verbiage to protect their ass from EPA, ARB, CARB, lawyers, and lawsuits.

 

Probably the latter.