If you are "modding" your Skoda and adding BHP then consider your oil choice carefully as the stock manufacturers recommended oil will not give you the protection that your engine requires.

A standard oil will not be thermally stable enough to cope with higher temperatures without "shearing" meaning that the oil will not give the same protection after a couple of thousand miles as it it when it was new.

Let’s start with the fundamentals. An engine is a device for converting fuel into motive power. Car enthusiasts get so deep into the details they lose sight of this!

To get more power, an engine must be modified such that it converts more fuel per minute into power than it did in standard form. To produce 6.6 million foot-pounds per minute of power (ie 200 BHP) a modern engine will burn about 0.5 litres of fuel per minute.(Equivalent to 18mpg at 120mph). So, to increase this output to 300BHP or 9.9 million foot-pounds per minute it must be modified to burn (in theory) 0.75 litres.

However, fuel efficiency often goes out of the window when power is the only consideration, so the true fuel burn will be rather more than 0.75 litres/min.

That’s the fundamental point, here’s the fundamental problem:

Less than 30% of the fuel (assuming it’s petrol) is converted to all those foot-pounds. The rest is thrown away as waste heat. True, most of it goes down the exhaust, but over 10% has to be eliminated from the engine internals, and the first line of defence is the oil.

More power means a bigger heat elimination problem. Every component runs hotter; For instance, piston crowns and rings will be running at 280-300C instead of a more normal 240-260C, so it is essential that the oil films on cylinder walls provide an efficient heat path to the block casting, and finally to the coolant.

Any breakdown or carbonisation of the oil will restrict the heat transfer area, leading to serious overheating.

A modern synthetic lubricant based on true temperature-resistant synthetics is essential for long-term reliability. At 250C+, a mineral or hydrocracked mineral oil, particularly a 5W/X or 10W/X grade, is surprisingly volatile, and an oil film around this temperature will be severely depleted by evaporation loss.

Back in the 1970s the solution was to use a thick oil, typically 20W/50; in the late 1980s even 10W/60 grades were used. But in modern very high RPM engines with efficient high-delivery oil pumps thick oils waste power, and impede heat transfer in some situations.

A light viscosity good synthetic formulated for severe competition use is the logical and intelligent choice for the 21st century.

You should seriously consider a "true" synthetic for "shear stability" and the right level of protection.

Petroleum oils tend to have low resistance to “shearing” because petroleum oils are made with light weight basestocks to begin with, they tend to burn off easily in high temperature conditions which causes deposit formation and oil consumption.

As a result of excessive oil burning and susceptibility to shearing (as well as other factors) petroleum oils must be changed more frequently than synthetics.

True synthetic oils (PAO’s and Esters) contain basically no waxy contamination to cause crystallization and oil thickening at cold temperatures. In addition, synthetic basestocks do not thin out very much as temperatures increase. So, pour point depressants are unnecessary and higher viscosity basestock fluids can be used which will still meet the "W" requirements for pumpability.

Hence, little or no VI improver additive would need to be used to meet the sae 30, 40 or 50 classification while still meeting 0W or 5W requirements.

The end result is that very little shearing occurs within true synthetic oils because they are not "propped up" with viscosity index improvers. There simply is no place to shear back to. In fact, this is easy to prove by just comparing synthetic and petroleum oils of the same grade.

Of course, the obvious result is that your oil remains "in grade" for a much longer period of time for better engine protection and longer oil life.

If you would like advice then please feel free to ask.

Cheers

Guy

Welcome oilman !

Was looking for an advertisement for a minute

Welcome Oilman. Interesting stuff. Do you think it would be worth upgrading to fully synthentic from the semi synth that the car comes with, or that the dealer puts in at service, for a non moded Octy vRS.

Welcome Oilman. Interesting stuff. Do you think it would be worth upgrading to fully synthentic from the semi synth that the car comes with, or that the dealer puts in at service, for a non moded Octy vRS.

There are alway benefits to moving to a full synthetic. The car comes with semi for two reasons. The first is cost, the manufacturer is not going to give away fully synethetic oil. The other reason is to bed the engine in, this tends to be done with a mineral multigrade or a semi synthetic.

So instead of using a mineral multigrade oil to bed in the new engine and then put in a full synethic at first service it is easier and cheaper for the manufacturer to use the semi synth.

Cheers

Guy.

Aha, you are the chap who posts on Pistonheads too! Welcome and thanks for the advice. What specific brands/types of oil would you recommend?

Aha, you are the chap who posts on Pistonheads too! Welcome and thanks for the advice. What specific brands/types of oil would you recommend?

Yep, thats me.

As these cars are VW if you look in your handbook you will find a set of codes listing the oil to be used, it will look a little like VW505.00 or something.

Let me know what cars you have an I can source the correct OEM recomendation. But the codes are the first place to start.

Cheers

Guy.

For non PD TDI engines it's VW 505.00

For PD TDI engines it's VW 505.01

For non PD TDI engines it's VW 505.00

For PD TDI engines it's VW 505.01

As one point of thought, Fuchs do all the factory fill for VW engines providing over 15,000,000 liters of oil per annum for factory fill.

WV505.00 There are lots of choices available for this code.

WV505.01 Not many choices for these, I always recomend the Fuchs PD oil as this oil was designed for the PD by Fuchs for VW.

Cheers

Guy.

What about the Quantum stuff that you can buy from the VW dealer? Is this stuff any good?

What about the Quantum stuff that you can buy from the VW dealer? Is this stuff any good?

It is ok, it passes all the tets for VW approval. However it is made to a cost, a little like tescos home brand cole, it passes all the test for human consumption!!! but it is still not that nice.

Cheers

Guy.

Where can you get Fuchs PD Oil and do you have a Part Number for it (and an RRP?)...

I need some to top up my PD130.

I'm glad someone else is raising the point of the extra heat in modded engines! I've taken a second approach of using a product called radiator relief from www.agriemach.co.uk to make what is already a very heat efficent engine even better! And yep it works as the fan rarely kicks in.

If you are "modding" your Skoda and adding BHP then consider your oil choice carefully as the stock manufacturers recommended oil will not give you the protection that your engine requires.

Presumably spec VW503 00, 506 00 and 506 01 oils (which come in the same container if you buy Castrol SLX Longlife II or similar) do not fall into that category? Are there better oils about which are suitable for variable service intervals; which will be 'recognised' by the sensors in the engine; and which will provide adequate lubrication for the top end of the PD engine?

Millars do a very good oil to vw specs for the pd always comes out looking as good as when it went it.Its the XFE-PD and usually

thanks for the advice Guy, I'll be switching fully synth then. Only had a 40k service 4000 miles ago and oil is looking a bit mucky already. Might just do an oil & filter change for now. What do you reckon?

Smifffy 3 f's, what oil and type of service schedule have you been using so far? The car came with a fully synthetic spec VW503 00 LongLife oil from the factory. If you have been using a lower spec oil than that since the first service, why?

Just been using the Quantum stuff that the dealer puts in. I have it serviced every 10k though 'coz I do quite a high mileage.

I would only use the Castrol LongLife stuff. As for Millers, they dont do an oil suitable for Long Life servicing set engines.

Mine is on the Castrol longlife stuff, but a tenner a litre is expensive stuff

hey Oilman, I take it you are the same person who posts on the MX5 forum as well :D:D:D:D

Mine is on the Castrol longlife stuff' date=' but a tenner a litre is expensive stuff

hey Oilman, I take it you are the same person who posts on the MX5 forum as well :D:D:D:D[/quote']

But if it means 1 less service per about 10k then thats money saved surely?

I agree, but its still expensive

Smifffy 3 f's, what oil and type of service schedule have you been using so far? The car came with a fully synthetic spec VW503 00 LongLife oil from the factory. If you have been using a lower spec oil than that since the first service, why?

The official Skoda in Greece recommends Valvoline 0-30 synthetic compatible with VW503.00 longlife service, but I think that every synthetic lubricant under this recommendation (VW503.00) could be used (Castrol, Motul, Aral, etc). One could also use, in particular for moded-chipped cars, the synthetic recommended for the high-powered 1.8T engines; Audi S3/TT 225bhp, which is covered under the VW503.01. In the latter case changes should be carried-out every 7.500 Km.

That's all I know about lubricants for our cars...

Chris, does the Octavia 1.8T sold in Greece come from the dealer set for extended service intervals of up 30,000K between oil change intervals? I haven't heard of anyone here using a VW 503 01 oil in a tuned 1.8T but I seem to recall talk of Castrol Formula RS 0W-60 oil being used. Paul (ffelan) might be able to advise.

Where can you get Fuchs PD Oil and do you have a Part Number for it (and an RRP?)...

I need some to top up my PD130.

I can get Fuchs for you' date=' e-mail me at [email'][email protected][/email] and I will forward prices etc on to you.

Cheers

Guy.