Oil Basics

[oilman]

A short lesson on Multigrades:

 

If you see an expression such as 10W-40, the oil is a multigrade.

 

This simply means that the oil falls into 2 viscosity grades, in this case 10W & 40.

 

This is made possible by the inclusion of a polymer, a component which slows down the rate of thinning as the oil warms up and slows down the rate of thickening as the oil cools down.

 

It was first developed some 50 years ago to avoid the routine of using a thinner oil in winter and a thicker oil in summer.

 

For a 10w-40 to attain the specification target a 10W ( W = winter) the oil must have a certain maximum viscosity at low temperature. The actual viscosity and the temperature vary with the viscosity grade but in all cases the lower the number, the thinner the oil, e.g. a 5W oil is thinner than a 10W oil at temperatures encountered in UK winter conditions.

 

This is important because a thinner oil will circulate faster on cold start, affording better engine protection.

 

For a 10w-40 to attain the other specification target a 40 oil must fall within certain limits at 100 degC. In this case the temperature target does not vary with the viscosity grade, if there is no "W", the measuring temperature is always 100degC. Again the lower the number the thinner the oil, a 30 oil is thinner than a 40 oil at 100 degC., which is typical of maximum bulk oil temperatures in an operating engine.

 

The engine makers are, of course, very well aware of this and specify oils according to engine design features, oil pump capacities, manufacturing tolerances, ambient temperature conditions etc. It is important to follow these guidelines, they are important and are an are stipulated for good reasons.

 

If the engine has been modified, the operating conditions may well be outside the original design envelope. The stress on the oil caused by increased maximum revs, power output and temperature may indicate that oil of a different type and viscosity grade would be beneficial.

 

Cheers

Simon

[Masked Marauder]

Oilman, when you started posting on MIG you did it exactly the same way as this and now on MIG, all be it some time on, your subtly selling your wares. Indeed this post is just a paste-up of the first one you put on MIG.

 

So is this just the start of another marathon subtle spamming campaign? Because if it is then from my experience of this site you will be wasting your time as the majority of users have their vehicles dealer serviced. In addition to this many, many of them are PD TDis which require special oil.

[oilman]

Ok, if it is not of interest feel free to remove it.

 

Cheers

Simon

[NikpV]

had a quick look - recommended oil is a bit pricey

[tim-spam]

Basically, a 5W40 oil has the same viscosity as a straight 5 oil at 0 degC, and a straight 40 oil at 110 degC.

[Guest marcusheawood]

What's the lowdown here tim? WTF is oilman on about? wot's MIG? WTF is going on; I know this forum has become a little, shall we say 'lowbrow', but things are getting desparate if we've got the f**king jehovahs witnesses on here!

[Masked Marauder]

What's the lowdown here tim? WTF is oilman on about? wot's MIG? WTF is going on; I know this forum has become a little, shall we say 'lowbrow', but things are getting desparate if we've got the f**king jehovahs witnesses on here!

MIG is another car site that I hang about on. Oilman put the same post up as the one above in the same "matter of fact" way.

 

This then prompted discussions about oils which he joined in on and followed up his first post with more matter of fact stuff about oils.

 

At no point did he post on any other threads, just his oil ones, getting into technical stuff about oils.

 

Then come the car show season he was posting details of the shows where his company would have a stand and be selling top quality oils at discounted prices. Indeed a bargin if that is what you need.

 

But as I said, not many people on this site will be interested in what he is selling.

 

But that said, when it comes to oil he seems to know his subject.

[tim-spam]

What's the lowdown here tim? WTF is oilman on about? wot's MIG? WTF is going on; I know this forum has become a little, shall we say 'lowbrow', but things are getting desparate if we've got the f**king jehovahs witnesses on here!

I think most would agree that it is only this sort of ranting that lowers the 'brow' of this (or any other) forum.

[johnb80]

I'd agee 100%, thats why I'm starting an alternative forum. I have tried to get the owner to agree to appoint a moderator but so far I haven't had a reply. I feel this current forum is failing and it's demise is imminent, many good people have left because of personal insult etc. Having a laugh is one thing, these goings on are totally different.

 

Regards - John

[Guest marcusheawood]

Thanks for the clarification MM, the question should've been directed your way, I erroneously thought tim-spam had posted the relevant remarks; duh!

 

I see Roger Irrelevant is in fact here after all :blink:

 

Why do I get the feeling that there is someone staring at my backside... :ph34r:

[Ex-Vec]

Oilmans' okay, I know of him from the Vectra Owners Club which I co owned. He was never slated or badgered there.

 

Not everybody is an ebay scamster!

[Masked Marauder]

Oilmans' okay, I know of him from the Vectra Owners Club which I co owned. He was never slated or badgered there.

 

Not everybody is an ebay scamster!

I never suggested anything like that, I simply said that he posts the same stuff in the same fashion on a mutitude of other car sites.

 

Does that make him a scammer? No.

 

Does that make him a spammer? Perhaps, it depends on your outlook.

 

I was simply pointing out to him that the vast majority by far on this site will only use the recommended oils for various reasons, and thus will be unlikely to buy his wares.

 

So I don't consider that I either slated or badgered him.

[Ex-Vec]

Wasn't really havin' a pop, just merely suggesting the Oilman was okay. :lol:

[NikpV]

slated or badgered

 

I don't think I did either - I asked for the recommended oil (on his website) - got the correct one but just seemed a bit expensive

[Masked Marauder]

I have no doubt he knows his stuff, but I ask myself, if he was not in the business of selling oil then would he be so active everywhere?

 

But as I said initially, I have no problem with him posting and his oils are quality at a good price. Just that he could be wasting his time here.

[Guest Snooper601]

Found the best solution to my oil supply was to go to the local Vauxhall agent and buy all their 25L drums of 0W30 Synthetic at