ASDA 20W50

[MarkyB]

Interesting article about it here;
http://www.scientificamerican.com/artic ... e-recycled



We clean that used oil by using pretty conventional refinery technologies. One of them is vacuum distillation, which dewaters the oil. Used motor oil comes with somewhere between 5 and 7 percent water in it. The first thing you have to do is get the water out of it.

Then we do wiped-film evaporation. This essentially separates out all the contaminants and additives that are put into passenger car motor oils. Then after that, we go through a hydrotreating process that gets up to 700 degrees Fahrenheit and 1,100 [pounds per square inch]. That infuses hydrogen back into the hydrocarbon molecules and makes it a very high quality re-refined oil.

[bmcecosse]

When you say 'we' Marky - are you involved in this process?? Place I nearly went to work (many many moons ago) got sufficient 'diesel' from the used oil at that first vacuum distillation to run their fleet of collection tankers...... I agree - assuming it's not from a back-street source - the re-refined oil is fine for reasonably standard A series. I wouldn't be putting it in my 'modern' car - because it's engine is designed to run on super thin 0W30 'synthetic' oil........which apparently lasts a very long time - yet the warranty compels me to change the oil every year..... I can however confirm that it makes very good 'lighting up' fluid !

[MarkyB]

Sorry, I should have put quote marks round it as it was a quote from the link I supplied.
I work in IT at the moment and have no affiliation with any oil company!

[chickenjohn]

Interesting article about it here;
http://www.scientificamerican.com/artic ... e-recycled



We clean that used oil by using pretty conventional refinery technologies. One of them is vacuum distillation, which dewaters the oil. Used motor oil comes with somewhere between 5 and 7 percent water in it. The first thing you have to do is get the water out of it.

Then we do wiped-film evaporation. This essentially separates out all the contaminants and additives that are put into passenger car motor oils. Then after that, we go through a hydrotreating process that gets up to 700 degrees Fahrenheit and 1,100 [pounds per square inch]. That infuses hydrogen back into the hydrocarbon molecules and makes it a very high quality re-refined oil.

As a former research chemist, some of the above sounds like gobbeldy gook pseudo science! Hydro carbon molecules already have hydrogen and carbon in them. It is not possible to "infuse hydrogen" back into the molecules, not without catalysts.

And no mention of how they get rid of the antifreeze and brake fluid from the oil!

[bmcecosse]

Vacuum distillation - under heat, will do the job nicely....... If it's re-refined then yes catalysts will be used.....

[MarkyB]

Here is another page on the same topic, as with the first one aimed at a general audience rather than chemists.
http://en.wikipedia.org/wiki/Automotive_oil_recycling

[wilfred]

Does new engine oil deteriorate over time if unopened?
Let's say you've got a 20 year old gallon of Duckhams 20/50 on the shelf in the garage. Will it still be usable or does the chemical structure change over time, as old oil left standing does?

[JOWETTJAVELIN]

Does new engine oil deteriorate over time if unopened?
Let's say you've got a 20 year old gallon of Duckhams 20/50 on the shelf in the garage. Will it still be usable or does the chemical structure change over time, as old oil left standing does?

It will probably deteriorate, but the only way to find out is by pouring some into a glass, observe the colour and smell it. If it's Duckham's it should be a nice translucent green.

I have some old oil, a little glass bottle of 1930s machine oil which has turned brown, and a full can of ancient Delco-Remy Vauxhall shock-absorber fluid which seems OK.

For the cost of fresh oil, I wouldn't like to risk it on a good engine but if I was running one in, or had a worn-out old oil burner, then why on Earth not!

[lambrettalad]

just back from newark auto jumble and here are the results all five litres

Fuchs oil 20 50 classic £20
Castrol classic £20

Millers 20 50 £12
comma 20 50 (plastic can?)£8.50
comma 20 50 (tin tin) £16
morris? £16-£19

interestingly the castrol oil can had no api rating,didn't check the rest

great selection of proper auto/bike jumble only a few teddy bears ,ribbons and bows etc,also lots of classics turned out,just whish I had more time to see them all

[lambrettalad]

noticed in halfords today their classic 20/50 has api on the tin

[JOWETTJAVELIN]

noticed in halfords today their classic 20/50 has api on the tin

It's what I use and keep harping on about!

[lambrettalad]

just come across a pint of straight 30 and couldn't for a while work out why I bought it for the moggie? then I remembered it's for my vespa gearbox this getting old lark .....................is better than the alternative

[Matt]

I have no evidence to support it...

But I believe the Halfords 20w50 to be Comma Classic oil (the one in the metal tin) but with a ~20% mark up ;)

They are both the same colour, and both come in the same shape can with the same colour scheme... both have same API rating etc!

[lambrettalad]

if it looks like a duck ,quacks like a duck..................

[chickenjohn]

20% extra is for the fancy metal tin! ;-)

[Matt]

You get the metal tin when you buy the comma stuff too... exactly the same shape!

http://www.pistonheads.com/gassing/topi ... 5&d=0&nmt=