Will the chemistry of low visc oils catch up to physical properties of thicker ones

[Garak]

Originally Posted by demarpaint
I agree. Everything seems to be a trade off.

Yes, unfortunately, there's no free lunch. It's hard to argue against the fuel savings of thinner oils on the driving public as a whole. Demonstrating a tangible fuel savings to me by going down a grade personally is virtually impossible.

 

[Kamele0N]

Originally Posted by Cujet
I now have an hour and 10 minute commute, often in snow. I won't be doing it on a 50cc scooter. Nor will I be doing it in a tiny car. I want some mass around me when skidding highway vehicles hit me. An F150 4x4 will work.

Small cars are not the answer. The Tesla Model S is proof of that. Efficient, fast, safe, capable. Technology is always the right answer.


Opel Mokka X....or GM traxx or Buick Encore is what you need...

 

[nap]

Something interesting about wear vs viscosity. Check the charts here:

https://hondakarma.com/data/attachm...owertrains_Fuels_and_Lubricants-2010.pdf

especially those that reference this paper:

https://www.sae.org/publications/technical-papers/content/922342/

They suggest that, when reducing viscosity, excessive wear does not start to show as a directly, strongly coupled factor, but more like an increased statistical probability of occurence. I.e. by reducing viscosity, you don't guarantee excessive wear, you are only increasing the chance of producing it.

This creates the opportunity for an oil manufacturer to "pass" the API wear criteria in the same manner that some pharma shops "pass" FDA requirements - you repeat the test many times and retain / submit only the succesful results.

This might also shine some new light on the old spat between famous brands on whether a particular oil met or not the API specs.

 

[Garak]

That wouldn't surprise me in the least, and I believe SonofJoe has mentioned that possibility, particularly for your second last sentence.

 

[fdcg27]

Originally Posted by SonofJoe
Originally Posted by bbhero
Originally Posted by SonofJoe
Silk,

You do realise that what you're saying will be seen by some of our more extreme BITOG brethren as dangerous heresy? Small engines will be seen as creeping Socialism! You'll be saying universal healthcare is a good thing next!!



^^^^^^

True I have to say...

The weight or safety in those "smart" cars though is not really all that great... Second point of note... Is that many people in this country live quite a distance from work or other places like grocery stores, school etc.. this country is way, way bigger than yours. Third point is there are still a sizeable number of people who actually live where the extra room and power is needed and used on a daily basis.

I do think that for people living in the large urban centers of the US could be served quite well with a smaller motor/smaller vehicle. Especially when all they do is stay in those large urban centers.

I do not care for the big donkey whoomping sized SUVs and CUVs... But it is not my place to tell others what to drive.. And it should not be the govt job either to do so.



BBHero,

I accept all of the above but might add the following...

Regarding safety, like a lot of BITOGers, I started driving in the 1970s. The cars I drove back then we're bigger than what I drive today but they were complete death traps! I drove a Morris 1100 that was full of rust, had no airbags, had remould tyres, leaked brake fluid into the rear drums & had a hand brake that the wife ripped out of the floor one day, yet I survived! In relative terms, the 845 kg (1837 lb) car I drive today, with it's ABS, six airbags, electronic stability control, etc, etc is infinitely safer.

Yes, we are a small country but if you want, you can still rack up the miles here. We're currently visiting relatives & it's a 500 mile round trip. That may not sound much by US standards but these days my driving is constrained not by the car but my ability to concentrate for six hours straight. There are plenty of cars just like mine for sale which are a couple of years old with 50,000 miles on the clock so they will 'mile munch' quite happily if that's what you want to do.

BTW, no one 'forces me' to drive a small car. It's very much my own choice. However I do see the day approaching when 'personal choice' has to be
severely restricted for the good of everyone. England has just had its hottest summer since records began. I think Japan & many other countries saw the same. I may be be an atheist but even I can tell when God is sending us a message which we're ignoring at our peril!





I've driven a 25 mile each way commute for decades now and was perfectly happy driving a Honda Civic Wagon back when we had a couple of them. There is neither a need nor any good justification for those who select outsized and overweight vehicles for daily driver duty.
The way in which we'll restrict vehicle choice in this country is through a carbon tax, or merely greatly tightened CAFE requirements.
Nobody would lack freedom of choice, but they would be made to pay the external costs of their choices.
Either a carbon tax or enhanced CAFE penalties would be a free market way of encouraging buyers to select efficient vehicles.
A sharply higher fuel tax would be another and many think that we need this merely to rehabilitate our crumbling surface infrastructure.
These approaches wouldn't take away anyone's freedom of choice but would merely steer them in the right direction through their wallets.

 

[ZeeOSix]

Originally Posted by nap
Something interesting about wear vs viscosity. Check the charts here:

https://hondakarma.com/data/attachm...owertrains_Fuels_and_Lubricants-2010.pdf

especially those that reference this paper:

https://www.sae.org/publications/technical-papers/content/922342/

They suggest that, when reducing viscosity, excessive wear does not start to show as a directly, strongly coupled factor, but more like an increased statistical probability of occurence. I.e. by reducing viscosity, you don't guarantee excessive wear, you are only increasing the chance of producing it.


Depends on the conditions the oil is used in. If you raise the oil temperature significantly by pushing an engine to the extremes (ie, extended track use) with a lower HTHS oil, then of course the chances of metal-to-metal contact will increase dramatically because the MOFT is reduced with even more with thinner oil being at very elevated temperatures (ie, lower HTHS). Goes right back to the reason why manufacturer always recommend higher viscosity oil (ie, higher HTHS oil) for track use type conditions.

 

[fdcg27]

A point to remember is that engines do wear without regard to the HTHS of the oil used or its add pack.
Wear is inevitable and is not usually a problem with vehicles in typical use for their entire working lives.
Something will lead to the retirement of every regular use vehicle out there and it won't often be due to engine wear related to oil used.

 

[BrocLuno]

It depends on where you live and work ... Out here chassis can last a long time. I sold a 1955 Ford F2 a few years back that had been on the ranch for long time. So long that after the second inline-6, it got an SBC for a bit more power and hill climbing. It's brother was a 1962 Ford F-100 that lasted with us for more than 40 years and three engines. Rust is not our concern. Cranks, rods and rings are ...

If I can save one engine replacement in those sorts of life spans, I have paid off all the extra fuel used many times over due to oil viscosity.

To easterners who live in the rust belt, I would never worry about engine wear. The chassis will go first.

And on lease cars, I'd run the thinnest oil I could get away with as gasoline is a real expense with no ROI for thicker oils ...

 

[nap]

Well the quoted test was conducted on 45 taxi cabs, I doubt they were racing them at the track while off duty...

My interpretation is more on these lines:

- use thick oil, 99% of engines will make it past let's say 300k miles
- use thin oil, 90% of engines will make it past 300k

Anecdotal evidence will still show that "the vast majority of engines last 300k or more, regardless of viscosity", yet I still wouldn't want to be among the 9% in difference between the full stats....

 

[ZeeOSix]

Originally Posted by nap
Well the quoted test was conducted on 45 taxi cabs, I doubt they were racing them at the track while off duty.


Like I said ... the point being that it all depends on how the vehicle is used. But the bottom line is higher viscosity oils (which typically have higher HTHS) will protect engines better in extreme conditions and give better insurance against wear.

 

[ZeeOSix]

Originally Posted by fdcg27
A point to remember is that engines do wear without regard to the HTHS of the oil used or its add pack.
Wear is inevitable and is not usually a problem with vehicles in typical use for their entire working lives.
Something will lead to the retirement of every regular use vehicle out there and it won't often be due to engine wear related to oil used.


Of course engines still wear out regardless of what you do. But as many studies have shown, the comparative wear level is less with higher HTHS oils.

 

[fdcg27]

..and it matters not at all unless the engine wears out before the rest of the vehicle does and that never seems to happen for most users.

 

[nap]

Originally Posted by fdcg27
A point to remember is that engines do wear without regard to the HTHS of the oil used or its add pack.
Wear is inevitable and is not usually a problem with vehicles in typical use for their entire working lives.
Something will lead to the retirement of every regular use vehicle out there and it won't often be due to engine wear related to oil used.


I'd like to suggest that, other than a catastropic failure, the "something" you mention is usually a combination of factors (not a single factor).

Anecdotal evidence sitting on my driveway: a high mileage vehicle that I'm considering junking shortly.

The factors:

- engine lost some torque (although it doesn't burn oil, make funny noises or other ailments)
- worn interior
- outdated amenities (no gps, cameras, sensors, the sound system is crude by today's standards etc)

Interestingly enough, the frequently invoked rust is not an issue at all, although my location would had suggested otherwise.

Taken individually, none of the factors would had conducted to the junking decision. It is only in combination that they work. If the engine was to be in better shape, I would be looking at keeping the car a couple more years.

 

[ZeeOSix]

Originally Posted by fdcg27
..and it matters not at all unless the engine wears out before the rest of the vehicle does and that never seems to happen for most users.


Maybe for some, but not everyone thinks like that. There are still benefits to keeping an engine wearing out at a slower rate than not.

 

[PimTac]

This is going back and forth on semantics. 90% of drivers don't work their engines. Engines will outlast the body and chassis in most cases.

Choose the grade of oil that fits your usage of the vehicle.

 

[nap]

Originally Posted by wemay
Shannow [...] Your inference that by me questioning the use of of "outdated" studies means it isnt to be considered is misdirected. Things change in science all the time. A novice like me is just interested if those conclusions still hold true.


Being at the receiving end of "the paper you quoted is outdated / old / etc" comments too, let me clarify how this actually works:

A paper doesn't become "obsolete" just through sheer age. It becomes obsolete only when a new study, benefiting of new materials, technologies or methods is published, and it either refines or disproves the previous paper.

Anyone intending to dismiss Stribeck's work "because obsolete" should better be prepared to provide a link to the newer study. Same with any other paper.

 

[hatt]

Originally Posted by fdcg27
..and it matters not at all unless the engine wears out before the rest of the vehicle does and that never seems to happen for most users.

Maybe for econoboxes in the rust belt. Not so much with trucks in much of the country. There are plenty of 20+ year old vehicles running around here. People don't take good running trucks to the junkyard.

 

[hatt]

Originally Posted by ZeeOSix
Originally Posted by fdcg27
..and it matters not at all unless the engine wears out before the rest of the vehicle does and that never seems to happen for most users.


Maybe for some, but not everyone thinks like that. There are still benefits to keeping an engine wearing out at a slower rate than not.

Yep. Engines don't go from new condition to worn out scrap metal in one step.

 

[Shannow]

Originally Posted by nap
Originally Posted by wemay
Shannow [...] Your inference that by me questioning the use of of "outdated" studies means it isnt to be considered is misdirected. Things change in science all the time. A novice like me is just interested if those conclusions still hold true.


Being at the receiving end of "the paper you quoted is outdated / old / etc" comments too, let me clarify how this actually works:

A paper doesn't become "obsolete" just through sheer age. It becomes obsolete only when a new study, benefiting of new materials, technologies or methods is published, and it either refines or disproves the previous paper.

Anyone intending to dismiss Stribeck's work "because obsolete" should better be prepared to provide a link to the newer study. Same with any other paper.


Thankyou...

 

[wemay]

Like i said, not in the business nor have i ever been. I wouldn't know whether a new study existed or not (although i try to back my opinions with as much cited material as possible). This is why questions are asked. Or at least from my perspective. Others may use that question as a veiled attempt at discrediting you and that's a shame, but so is, jumping to the conclusion that everyone who makes that inquiry is cynical.