What’s With the Oil Viscocity.

My wife’s 2012 Honda specs 0w-20, and that’s all it’s ever had. It’s approaching 100k miles, and doesn’t use a drop. If that’s what the OEM recommends, that’s what I’m going to use.

The biggest reason for engine oils of this weight, is that machining tolerances can now be held much tighter, more consistently, for greater numbers of parts, than in the past. This makes for closer fitment, which reduces material needed, which reduces weight and cost. These closer fitments of parts, requires an oil capable of flowing into smaller spaces.

We can start discussing advances in oil technologies too, but that deceased equine has nothing left to pound. It’s all out there, you just need to find it.

At the end of the day, it’s your truck and you can do what you want with it. Just don’t be one of those guys that comes pissing and moaning that your truck is broke, when you didn’t follow the recommendations of the manufacturer.

 

Its pretty much impossible to figure out what the engineers were thinking, what their constaints were or who was pushing them to do what. Am an engineer, and the number of competing priorities on projects like these is just brain melting.


That said, sometimes I think new vehicles are getting too complicated and too picky. But that's the price of ever increasing cost optimization and fuel efficiency, so its not going away.

 

Agreed. There are too many outside factors influencing designs of vehicles and engine designs to work and run how they really should to get the most power out of them and last the longest they truly could. It is all about making sure they run as clean as possible and get the highest fuel economy obtainable by the manufacturer.

 

[QUOTE="
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.[/QUOTE]

Yes it does. A thicker oil will not hurt the engine.

Page 632, 2019 manual.
• The 20 in 0W-20 indicates the viscosity characteristic of the oil when the oil is at high temperature. An oil with a higher viscosity (one with a higher value) may be better suited if the vehicle is operated at high speeds, or under extreme load conditions.

 

I canned statement from Toyota in most manuals. The Tacoma wouldn’t meet either criteria. Nobody is going fast in their 3rd gen, and if they’re operating under extreme load, engine oil will likely be the least of worries. I doubt anyone is actually doing something that extreme with their truck, and if they are and something breaks anyways, vehicle abuse will be attributed to it before they even check the viscosity of the oil.

 

You are about 40 years behind. Don't blame it on being old as I am old. Blame it on not keeping up.

 

In my time (30+ yrs) of being an engineer I have seldom seen failures of any kind when the maintenance schedule is followed to the letter with no modifications. To me proof has been over time. Owners will take the Blackstone lab chart, which is actually the only provable data available, and use it to prove that 0W-20 works fine and 10K is a suitable interval.

It's funny you talk about Prius because, if those dumbasses ever learned how to check their oil level there would be very few problems.

 

Don't look under the hood of the Rav4. 0-w16. You can't even find that stuff at WalleyWorld.

 

I’ve got a Prius, but I only go with 5k intervals and check my oil weekly. Sometimes I’m a dumbass, especially when Jack Daniels is involved...

 

I have run 0w20-5w30 and 0w40 In my Taco. No performance issues, no warranty issues (even had dealers install the oil I brought) I keep the OCIs to 5k because cleanliness is more important than convenience to me.

A 0w20 at 100 degrees is still much thicker than a 0w40 weight at 190. The vvt-I doesn’t know the difference.. this isn’t a “RAM” truck. These engines are being commonly run on15w40 in Australia.
The 0w20 doesn’t have to pass key deposit test in the ILSAC sequence testing. That is why the rings on engines run exclusively in 0w20 are so nasty.

 

I pulled a trailer for 500+ miles on my last oil change. It was a 10k mile change (30-40k). It was visibly very clean when changed.

 

Manufacturing tolerances are much better than they used to be, 0W-20 is fine. But 5W-30 is probably also fine if that's what you want to do. As mentioned, the VVTI system is controlled by oil pressure, so I'd go with what the engine was designed to use for the best performance.

I've got 20W-50 in my '77 Celica right now.

 

5w40 and call it good.

 

Run a good 0W-20 with confidence.

 

Really? Another one of these threads?

 

No one has suggest extra virgins in their olive oil, so it is still too early to judge.

 

True.

 

This thread is getting interesting. Gonna keep up with this. @Bryanccfshr on the 3.5 in the tacoma, you're saying 0w-20 will make the engine get deposits and gunked up rings over time? Any links or proof of this? I'm not calling you wrong by any means. I'm just genuinely curious about it and having been enjoying all the input on this thread thus far

 

I'm holding out for fresh squeezed baby oil.

 

No problem, I wouldn’t make a statement without facts and I appreciate you asking.
Below is a source showing that the TEOST 33c high temperature deposit test is not required for 0w20 approval. Page 3.
The reason for this is that the base oils used to formulate 0w20 are more volatile(lighter base oils evaporate at lower temperatures)and the oils could not pass the test and meet the fuel economy sequence testing as well.

Specifying 0w20 is not engineering the best oil for the vehicle..it is a compromise specification to meet resource conserving goals with “adequate” performance.

https://www.ocsoil.fi/upload/News on Lubes/ILSAC-GF-5.pdf