Has anybody seen literature or numbers discussing how an oil's evaporation rate changes over the course of its service life?
Change in evaporation rate over time?
- Thread starter mosschops
- Start date
I don't think I've seen anything like that.
Maybe some additional context around your question will help with some more responses.
Maybe some additional context around your question will help with some more responses.
Let's say an oil has a published Noack value of 6% (tested on a virgin sample). At the end of the oil's service interval, say 20,000 miles, would the used oil's Noack value still be 6%? Higher? Lower?
We know that most, if not all, lubricant properties change during use. I haven't see any discussion or data regarding how the evaporation rate changes, though. Just something I'm curious about in an academic/hypothetical sense.
I expect the answer is that there is some difference, but not significant enough to be meaningful.
We know that most, if not all, lubricant properties change during use. I haven't see any discussion or data regarding how the evaporation rate changes, though. Just something I'm curious about in an academic/hypothetical sense.
I expect the answer is that there is some difference, but not significant enough to be meaningful.
Originally Posted by Rand
If you have one of those honda 1.5turbo engines that can get into double digit fuel dilution..
that could be totally different from a port injected 2L elantra for example.
Yeah I didn't consider fuel dilution. Would expect that to increase volatility of the mix, but you would really hope it would flash off and be carried into combustion.
If you have one of those honda 1.5turbo engines that can get into double digit fuel dilution..
that could be totally different from a port injected 2L elantra for example.
Yeah I didn't consider fuel dilution. Would expect that to increase volatility of the mix, but you would really hope it would flash off and be carried into combustion.
I had a similar question.
Easy to do an experiment - OUT of Doors on a hot plate. In a graduated beaker.
Its HAS to improve after an initial boll down.
The upper volatile solvents will "off" first.
So an oil may show 10% off in the first hour and then maybe 6% off in the next hour.
Easy to do an experiment - OUT of Doors on a hot plate. In a graduated beaker.
Its HAS to improve after an initial boll down.
The upper volatile solvents will "off" first.
So an oil may show 10% off in the first hour and then maybe 6% off in the next hour.
I'm curious about that with repeated fuel dilution. Like with DI.
I agree that evaporation should decrease over time. But I suppose that the shearing effect over time also has an effect on volatility... shearing causes reduced viscosity / increase in lighter components? Maybe wrong, just a thought.
No, as it's not the oil molecules that shear, but the viscosity improvers that are mixed in the oil. Shear should have only a minimal effect on volatility.
