Are Synthetics really better and why......

[oilman 0]

I thought this would be of interest as It's probably the question I get asked the most. Shame the answer isn't simple though!

 

The basic benefits are as follows:

 

Extended oil drain periods

Better wear protection and therefore extended engine life

Most synthetics give better MPG

They flow better when cold and are more thermally stable when hot

Esters are surface-active meaning a thin layer of oil on the surfaces at all times

 

If you want to know the reasons why then please read on but, warning - Long Post!

 

Stable Basestocks

 

Synthetic oils are designed from pure, uniform synthetic basestocks, they contain no contaminants or unstable molecules which are prone to thermal and oxidative break down.

Because of their uniform molecular structure, synthetic lubricants operate with less internal and external friction than petroleum oils which have a non-uniform molecular structure.

The result is better heat control, and less heat means less stress to the lubricant.

 

Higher Percentage of Basestock

Synthetic oils contain a higher percentage of lubricant basestock than petroleum oils do.

This is because multi-viscosity oils need a great deal of pour point depressant and viscosity improvers to operate as a multigrade.

The basestocks actually do most of the lubricating. More basestocks mean a longer oil life.

 

Additives Used Up More Slowly

Petroleum basestocks are much more prone to oxidation than synthetic oils. Oxidation inhibitors are needed in greater quantities in petroleum oils as they are used up more quickly.

Synthetic oils do oxidize, but at a much slower rate therefore, oxidation inhibiting additives are used up more slowly.

 

Synthetic oils provide for better ring seal than petroleum oils do. This minimizes blow-by and reduces contamination by combustion by-products. As a result, corrosion inhibiting additives have less work to do and will last much longer in a synthetic oil.

 

Excellent Heat Tolerance

Synthetics are simply more tolerant to extreme heat than petroleum oils are. When heat builds up within an engine, petroleum oils quickly begin to burn off. They are more volatile. The lighter molecules within petroleum oils turn to gas and what's left are the large molecules that are harder to pump.

Synthetics have far more resistance as they are more thermally stable to begin with and can take higher temperatures for longer periods without losing viscosity.

 

Heat Reduction

One of the major factors affecting engine life is component wear and/or failure, which is often the result of high temperature operation. The uniformly smooth molecular structure of synthetic oils gives them a much lower coefficient friction (they slip more easily over one another causing less friction) than petroleum oils.

Less friction means less heat and heat is a major contributor to engine component wear and failure, synthetic oils significantly reduce these two detrimental effects.

Since each molecule in a synthetic oil is of uniform size, each is equally likely to touch a component surface at any given time, thus moving a certain amount of heat into the oil stream and away from the component. This makes synthetic oils far superior heat transfer agents than conventional petroleum oils.

 

Greater Film Strength

Petroleum motor oils have very low film strength in comparison to synthetics. The film strength of a lubricant refers to it's ability to maintain a film of lubricant between two objects when extreme pressure and heat are applied.

Synthetic oils will typically have a film strength of 5 to 10 times higher than petroleum oils of comparable viscosity.

Even though heavier weight oils typically have higher film strength than lighter weight oils, an sae 30 or 40 synthetic will typically have a higher film strength than an sae 50 or sae 60 petroleum oil.

 

A lighter grade synthetic can still maintain proper lubricity and reduce the chance of metal to metal contact. This means that you can use oils that provide far better fuel efficiency and cold weather protection without sacrificing engine protection under high temperature, high load conditions. Obviously, this is a big plus, because you can greatly reduce both cold temperature start-up wear and high temperature/high load engine wear using a low viscosity oil.

 

Engine Deposit Reduction

Petroleum oils tend to leave sludge, varnish and deposits behind after thermal and oxidative break down. They're better than they used to be, but it still occurs.

Deposit build-up leads to a significant reduction in engine performance and engine life as well as increasing the chance of costly repairs.

Synthetic oils have far superior thermal and oxidative stability and they leave engines virtually varnish, deposit and sludge-free.

 

Better Cold Temperature Fluidity

Synthetic oils do not contain the paraffins or other waxes which dramatically thicken petroleum oils during cold weather. As a result, they tend to flow much better during cold temperature starts and begin lubricating an engine almost immediately. This leads to significant engine wear reduction, and, therefore, longer engine life.

 

Improved Fuel Economy

Because of their uniform molecular structure, synthetic oils are tremendous friction reducers. Less friction leads to increased fuel economy and improved engine performance.

This means that more energy released from the combustion process can be transferred directly to the wheels due to the lower friction. Acceleration is more responsive and more powerful, using less fuel in the process.

 

In a petroleum oil, lighter molecules tend to boil off easily, leaving behind much heavier molecules which are difficult to pump. The engine loses more energy pumping these heavy molecules than if it were pumping lighter ones.

Since synthetic oils have more uniform molecules, fewer of these molecules tend to boil off and when they do, the molecules which are left are of the same size and pumpability is not affected.

 

Synthetics are better and in many ways, they are basically better by design as they are created by chemists in laboratories for a specific purpose.

 

Cheers

Simon

[ZippyVR6 0]

they dont call you oilman for nuthin,

 

interesting post.

[Kevin Bacon 5]

Is that related to full synthetic or semi?

 

Synthetic is all well and good but certain brands and viscositys are no good for our old engines at all. Quantum Silver semi-synth seems to fit the bill perfectly for most of us. It doesn't seep through sump gaskets, doesn't burn off excessively quickly and doesn't cost £10 a litre.

 

Good info though, thanks for sharing it.

[oilman 0]

Fully synthetic only. Semi-synthetics are petroleum based.

 

Synthetics come in every viscosity from 0w-20 to 20w-60.

 

A 15w-50 fully synthetic is the same viscosity as a 15w-50 mineral or semi-synthetic.

 

Basically synthetics don't have to be thin, they are available in any viscosity to suit any car.

 

Cheers

Simon

[davidwort 0]

I thought this would be of interest as It's probably the question I get asked the most. Shame the answer isn't simple though!

 

The basic benefits are as follows:

 

Extended oil drain periods

Better wear protection and therefore extended engine life

Most synthetics give better MPG

They flow better when cold and are more thermally stable when hot

Esters are surface-active meaning a thin layer of oil on the surfaces at all times

...

 

you missed the most important benefit, the profit margins for the oil companies :lol:

 

BTW, if I had used Mobil 1 on my car from new I would have spent over 1000 quid on oil changes :shocked!: , who cares if it could lengthen my engine life a bit, I can get a complete rebuild for the extra I would have spent on fully synthetic :!:

 

David.

[dinkus 10]

I think the main question is not so much that synthetic is better, but how much better it is, especially considering that it costs many times that of a mineral equivolent.

 

It may last twice as long in the engine before it needs changing, but if it costs three times as much to start with, then I'd rather buy the mineral stuff and change it twice as often.

[Kevin Bacon 5]

Castrol Formula RS 10/60W is probably the best oil I've ever used, mainly because it reduced an old 1600 Jetta engine's oil consumption from 1 litre per 1000 miles ish (worn guides) to approx 1 litre per 2500 miles! I didn't notice any of the other claimed benefits though.

 

So it can be argued that if a synth is that good at controlling oil consumption, then savings can be made there I guess.

 

Cheapest I've seen it these days is £30 per 4 litres and it has to be ordered. I've only seen RS 0/40 in the shops. So it's gonna cost a VR owner £60.....1 and half cans for the refill and the remaining 2 for top ups. You can get 30 litres of Synta for that, so as David said, the profiteering from synth oils is immense.

[craigowl 0]

Just seen in Lidl supermarket (German chain - we have loads up here)

5 litres for £4.99

 

"VW 505.00

Suitable for all engines including modern turbodiesels....with added synthetic additives" I think it says.

Not putting it in the C but it could be good for those looking for cheap oil for leaky engine.

 

Off topic now - mods can change for me?

I bought another of their desktop calculators for £1.49!

Solar/battery power. I have had one for a year or two.

Also bought rechargeable battery powered tyre inflator for £9.99.

Our family has 3 or their Power Stations (car starters) - came out at £19.99 - you can pay double for same model in other stores.

Over past 3 years have spent loads on tools etc - some as cheap as £1.99 A SET chrome/moly and with TUV

certification.

Haven't seen them mentioned on here before but I go there nearly every other week.

see http://www.lidl.co.uk/gb/index.nsf/page ... 0808.index

[Scott 0]

Is that related to full synthetic or semi?

 

Synthetic is all well and good but certain brands and viscositys are no good for our old engines at all. Quantum Silver semi-synth seems to fit the bill perfectly for most of us. It doesn't seep through sump gaskets, doesn't burn off excessively quickly and doesn't cost £10 a litre.

 

Good info though, thanks for sharing it.

 

 

Kev - not meaning to disagree with you but I changed oil based on oilmans advice...

 

I run Silkolene Pro S 10w 50 in my modified 200 and its made a HUGE difference... so much smoother...

 

With you now running forced induction I would recommend you try this oil...

[Scruffythefirst 0]

Anyone who runs a turbo might like to bear in mind that your oil is used to cool the core (as well as lubrication and there also being water cooling). Turbos regularly get hot enough to glow white so I'll be putting fully synth in the Dax and changing it every 3k / trackday.

[Kevin Bacon 5]

Kev - not meaning to disagree with you but I changed oil based on oilmans advice...

 

I run Silkolene Pro S 10w 50 in my modified 200 and its made a HUGE difference... so much smoother...

 

With you now running forced induction I would recommend you try this oil...

 

No probs....

 

I don't mind using synth, it's just the cost! I did use Mobil 1 15/50W Motorsport in my 16V Turbo and it was good stuff, but that wasn't so bad as the sump capacity was 4 litres, so £30 ever 6 months plus top ups. The VR takes 6 Litres and pathetic little 4 litre tubs are no longer cost effective :?

 

How much is the Silky stuff mate as 10/50W sounds perfect for an ageing VR?!! What size tubs does it come in too???

[vr6storm 0]

 

No probs....

 

I don't mind using synth, it's just the cost!

 

 

 

 

of course Kev............there's always VW's very own Synta Gold................works out about

[oilman 0]

Silkolene Comes in 5L tubs, 10L is £72.99 incl carriage to your door.

 

This is an ester/pao proper synthetic race oil.

 

http://www.opieoils.co.uk/TechSpecs/PRO ... 0Wheel.pdf

 

Oil is cheap when you compare the rest of the running costs on your car per annum but it's you engines first line of defence!

 

Silkolene Pro S is good for 10 track hours or 9000-12000 miles.

 

Cheers

Simon

[Kevin Bacon 5]

vr6storm, Cheers Rodders, but I've used it in the past and found a wee bit thin for an old VW tbh, but I know you like it.

 

oilman, Cheers Simon. I'll send you a PM later about aquiring the Silkolene.

 

Cheers

K

[vr6storm 0]

vr6storm, Cheers Rodders, but I've used it in the past and found a wee bit thin for an old VW tbh, but I know you like it.

 

 

i LOVE it!!!! :D :D

[Supercharged 2]

You live in Scotland tho Rodders, with an average temp of -30 no oil is going to be too thin!

[vr6storm 0]

You live in Scotland tho Rodders, with an average temp of -30 no oil is going to be too thin!

 

thats only the summer months :D :D :D