Spotted this at the dealership.

 

As long as the pump can flow enough past a point at a high enough pressure to ensure hydrodynamic effect, and the load carrying of the oil is high enough for the amount of bearing surface any weight is fine.

 

The thing that concerns me the most is that in order for this oil to "make spec", they had to change the spec to allow for 4x as much iron to be suspended (400ppm vs. 100ppm for the 0w16 spec). The SAE paper goes on and on about how friction modifiers are being used as a substitute for viscosity, while pretty much ignoring that the real "success story" is that they just moved the goalposts.

But hey, it delivers a (claimed) 0.8% improvement in fuel economy. 75% shorter engine life for an extra 0.3 mpg sounds like a good tradeoff.

 

I remember when 0W20 started becoming the required oil for a lot of automobiles people were up in arms, but it turned out fine. The only way we know if this weight will cause lowered engine life is if we start seeing prematurely engine failures or oil analysis shows excess wear. I personally wouldn't be concerned

 

You can increase the bearing area to some extent to delay failures. It only has to make it past warranty after all....

It's possible it will be perfectly fine in most normal engines with a variable pump. Modern engines are throw away deals anyway

 

But then you increase friction the problem you are trying to reduce.

 

I think reduced clearances is what you want to achieve. Modern engines have been reducing clearances so that you can use thinner oils. The wider the clearance, the thicker the viscosity you would have to use

 

Not necessarily since you greatly reduce fluid friction with this in the first place, balancing the two for "optimal" result is possible. I'm not saying it will last as long but it will hit their goals at least.

They very well might just take the path of bigger oil pump and pray it holds and doesn't violently explode like a lot of the variable pumps tend to.

 

Or you just need to flow more.....clearances have not changed much at all. The first LS400 and the current LC500 actually have nearly the same clearances with the 400 being more demanding for the crank. Other lower end engines actually don't have the best clearances, you would be quite surprised how consistent nearly everything is sized these days and the main difference is oil flow level and the parts bearing size not so much viscosity.

The higher weights are only needed if you have a hell of a lot of load in a smaller part/high relative loading provided you are not trying to plan for temperature increases that can thin the oil and thus lower its capacity/load carrying. Size the pump big enough and it will flow enough to keep it pressurized, hydrodynamic, cool, and happy no matter the weight unless crazy loads are involved.

A low output engine like my 1UR-FSE can easily use 0w-20 but my Audi needs 40 weight since the parts are under 2x load and more heat for example.....older engines can't flow nearly enough oil so they use a heavier weight to provide more film strength and resistance to overheating in the actual bearing area since they don't move past those locations that quickly relatively speaking.

I did an experiment with this one time, I'll make another post describing what I did.

 

I think regulators and manufacturers should just accept petrol engines are not economical and move on.

Bigger gains in economy are in size and weight of cars. But no, we all want big SUVs with 20” rims 😀

Imagine the mpg gains if we stuck to sedans and 15” rims.

 

Great idea, I think this can be achieved if we pay the "Influencers" to make driving around in econo cars with 15 inch rims "Cool". A few Tick Tock videos should do it. Ah modern society lol.