Costs of synthetics vary considerably. The most expensive are the “Ester” types originally only used in jet engines. These cost 6 to 10 times more than high quality mineral oils.

 

The cheapest synthetics are not really synthetic at all, they are dug out of the ground and not manmade. These are in fact specially refined light viscosity mineral oils known as “hydrocracked” oils.

 

“Hydrocracked” oils have some advantages over their equivalent mineral oils, particularly in lower viscosity motor oils such as 5w-30 and 5w-40 and they cost about 1.5 times more than good quality mineral fractions. This is the “synthetic” which is always used in cheap oils that are labelled “synthetic”.

 

So, why are these special mineral oils called “synthetic”?

 

Well, it all came about from a legal battle that took place in the USA more than ten years ago. Sound reasons (including evidence from a Nobel Prize winning chemist) were disregarded and the final ruling was that certain mineral bases that had undergone extra chemical treatments could be called “synthetic”.

 

Needless to say, the marketing executives wet their knickers with pure delight! They realised that this meant, and still does, that the critical buzz-word “synthetic” could be printed on a can of cheap oil provided that the contents included some “hydrocracked” mineral oil, at a cost of quite literally a few pence.

 

So, the chemistry of “synthetics” is complex and so is the politics. The economics are very simple though.

 

If you like the look of a smart well-marketed can with “synthetic” printed on it, fair enough, it will not cost you a lot; and now you know why this is the case, it’s really only a highly processed mineral oil.

 

But, if you drive a high performance or modified car, and you intend to keep it for several years, and maybe do the odd “track day” or “1/4 mile”, then you need a genuine Ester/PAO (Poly Alpha Olefin) synthetic oil.

 

These oils cost more money to buy, because they cost a lot more money to make.

 

Very simply, you always get what you pay for, cheap oils contain cheap ingredients, what did you expect!

just to add 2p's worth to what the opie guys are saying. I am an engineer in the oil industry and what i understand by hydrocracking or hydrotreating is that, as most people know, the oil that comes out of the ground is made up of hydrocarbon chains of varying length. By boiling this mixture and condensing the vapours at certain temperatures can give you different grades or cuts of oil which have different characteristics and properties such as density and viscosity to do with the average weight of the molecules. However, in these cuts there are still hydrocarbon chains of varying lengths and shapes (such as circular aromatics like benzene) and chemistry that even out to the average weight. This mixture can sometimes not act as required due to the mixture of molecules being very varied and behaving unpredictably.

Hydrotreating involves heating specific cuts to high temperatures and pushing it through a reactor called a FCC (fluidized catalytic cracker) containing fine catalyst particles and blast Hydrogen molecules at it. The heat and presence of the catalyst and hydrogen breaks longer chains into smaller chains as required for the final product. Hydroforming works in a similar way in a different type of reactor to make short chains longer by pushing chains together. Thus the eventual blended product may have the same average weight as the distilled product but have a much narrower distribution of particles making up that weight and with more known about the chemistry of particles it contains. This will normally lead to the hydrotreated product behaving much more reliably than the distilled product.

 

Masters of Chemical Engineering Imperial College London

Good stuff lads, interesting.

so how can you tell the difference just by looking at the packaging?

so how can you tell the difference just by looking at the packaging?

 

if it has a £2.99 price tag from B&Q dont buy it :rofl:

if it has a £2.99 price tag from B&Q dont buy it :rofl:

 

i use scrumpy 5ltrs for £3.99

 

i always wanted to put ester ransom in my car all this talk about ester :nelson:

I once had Ester Ransom in my car and got pist-then-slapped

lol

if it has a £2.99 price tag from B&Q dont buy it :rofl:

 

very droll but unfortunately not very helpful :mac1:

added to the FAQ buying oil advice section :)