does anyone know if toilet paper has some degree of separation to oil? i'm sure it does! we should stock pile on that too then .

 

What do different driving conditions have to do with tolerances?

Its either about tolerances or about driving conditions, you can't use both explanations lol

The thin oils are used in the US for fuel economy, full stop.

 

I wasn't talking about tolerances. I was talking about driving conditions and environment that affect the wear OF those tolerances...and what oil-grades engineers feel are needed in different conditions to minimize that wear.

Also, today's multi-grade oils are not like the single-grade oils of the 1960s, when I first started driving. The viscosity (and level of engine-protection) varies with air and engine-temperature to cover that protection over a wider range than single-grade oils. An additional factor, in the U.S., is the CAFE requirements........0W-20 helps not only engine wear on start-up at cole temperatures, but also better fuel economy by lessening engine-friction during warm-up.

 

I think some people have already beaten you to that LOL.

 

This makes no sense lol.

It’s for fuel economy. Pick up a bottle of Mobil 1 0W20. What does it say on the bottle?

 

Read my post ..... I mentioned CAFE fuel economy. But how do you GET better economy? Like I said, by proving better lubrication, less drag, an easier flowing/start-ups in the winter.

 

Correct, potentially at the expense of protection from wear. Thats the point. The use of 0W20 oils in the US is just for fuel economy, if it was for better protection for the engine they would use that spec oil exclusively everywhere else in the world but they don't.

 

Someday I'll write a post about what ENGINEERS want and what MARKETING wants. Often at odds with each other but MARKETING wins. Always.

Moral of my story is - don't assume that because there is a recommendation or a requirement it's what the engineers wanted or even approved. That's not how it works.

 

100%. Great example of that is maintenance schedules. Ask engineers if 10k oil changes are frequent enough.

 

I wouldn't necessarily say Always, but, yes, I generally agree....a big majority of the time. That is why education of the consumer is so important. And why we discuss these things on Car Chat.

 

You know he’s an engineer, right?

 

You know it. Lol
So true.

Tnis is how the real world works just like you said.

 

Yes...and I respect his opinion. I did not argue with it except to point out that one should never say never. There were a few times when automotive engineers DID win out....such as with Chrysler in the early/mid-1960s, and Toyota/Honda in the late 80s/early 90s.

 

 

I'll try again, because it's far more nuanced than I probably portrayed it. We, as engineers, have our priorities and marketing will have their own.

I'm going to bring this in to airliners, because that's where 22 of my 27 years of engineering experience fall.

I can, for example, say that I can make a change that will cost an airline an extra $5M in fuel over the life of the airplane, but save them $8M in maintenance costs. Marketing can come back and say that X number of airlines only care about fuel costs, so this change will cost us sales overall, even if it saves them money in the long term. I do get that. So let's say, in this scenario, that the recommendation of my company the becomes "this isn't worth it because it costs us sales."

That shouldn't be interpreted as "engineering approves of not doing this change because it's technically better." We get it, but that's not what we said. We just didn't get our way but understand. This wouldn't be my choice, and not my recommendation, but it is what it is.

I relate automotive stuff to this viewpoint. If a manufacturer feels that "we can live with X number of additional failures (not recommended by engineering) because overall we'll sell more" I do get it. These companies are in it for profit and that does makes sense when viewed through that lens. I just would have made a different choice based on my engineering judgement.

I'm tired so I do hope what I wrote makes sense.