Jets1in

Hi

Its that semi synthetic products were designed to bridge the gap between mineral and synthetic technology. They were designed to take into account of issues such as cost of manufacture, meeting specification and availability of base oils etc. Shell Helix used to be a "more highly refined" product rather than a semi synthetic. The marketing guys were very carefull what it said on the tin. Not sure now though.

Being honest the lubricant specs required (I dont have them to hand) are not particulaly high for SUBARU. You also need to take account of the fact that SUBARU will sell products in many geographic locations around the world. High spec lubricants may not be available in some areas of say Brazil or Vietnam. Its a compromise situation which works.


Trust this helps

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by DJB:
<B>I can appreciate that a fully synthetic oil is "better" than a semi-synthetic in theoretical terms.

What I don't understand is why do Subaru recommend a semi-synthetic oil? Surely if there was a difference in engine/turbo durability, it would be in their interest to recommend a fully synthetic oil if this meant fewer engine failures and warranty claims. They don't pay for the oil after all - we do.

I suspect that they have tested both and concluded that fully synth is unnecessary for standard road cars.

D.

[/quote]

Jets1in

Not sure when the initial oil change is but I would stick with changing the oil then. Its either 1,500 miles I think but I am guessing. Id use what Subaru recomend at this stage. Its more important for the engine to be well beaded in than to use a synthetic at this stage.

At 7,500 you could change to a 0w 40 or 5w 40 or 10w 40 fully synthetic. Buy from a well recognised brand (Mobil, Shell, Castrol, Texaco etc). Please ensure the product excedes the SUBARU spec requirements most good synthetics will quote the current highest specs but its best to check this out.

Just a tip for your trip to Nurenberg. It may seem trivial but make sure there is sufficent oil in the sump. Particulaly if your going to throw it about a bit

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by ian/555:
<B>What would be the general consciences be that I do in my position, with regards to which oil type I use. As I am going to the Nurburgring in less than 3 weeks time and my car has only covered just over 1000 miles.

Should I use synthetic or use a mineral based oil or even a semi synthetic?
Also which viscosity range would be best suited for the task?

Thanks Ian[/quote]

RobJenks

Gentlemen,
This is the oil that really offers maximum protection , especially if you are going down the path of raising boost etc.

Jets1in

Interesting site. Check out the dyno results that prove synthetic lubricants advantage on the DYNOMETER

Dave T-S

Jets1n
You obviously know your oil, but why can't I help getting the feeling you have just come on here to try and impress us (or sell something)??

Jets1in

Hmmm........ If someone picks up a bit of usefull info from all this I will be a happy man.

If you look carefully you will see I have not recomened any specific companies products and I wouldnt.....it would be un eathical for me to do so.

I try to take stuff on face value too

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by Dave T-S:
<B>Jets1n
You obviously know your oil, but why can't I help getting the feeling you have just come on here to try and impress us (or sell something)??[/quote]

PeteT

Does anyone know of any Motul or Redline stockists (apart from Demon tweeks)?

harrydog

Those who said to use an oil with a smaller gap (10w30, 15w40) rather than a wider spread (0w40, 5w50) are correct. Even synthetics need to use viscosity index improvers (VI's) to get this large spread. The VI's are less stable under extreme heat and shear stress and tend to crack, or break down, causing sludge and other problems.
Also, not all synthetics are created equal. The best basestocks are polyolesters as compared to the cheaper PAO's. Redline and Motul are the only two brands that I'm aware of that use polyolester basestocks in their oils. They are the best.

Pete Croney

Harrydog

Silkolene Pro S is also Polyolester. Its rated as 10w50.

NIGE K

I am now using Shell Helix Ultra 5w40 on a trial basis after Shell agreed with the dealership (who supplied my P1) that they would warranty any engine problems caused by the oil. They have been talking to IM in a bid to have this oil as the recommended one rather than the semi now in use.
As to the increase in power at the wheels the Well Lane rolling road indicated 293bhp. The other benefit I can see is that this oil will be far less likley to break down under the high temperatures associated with the turbo especially after stopping the engine.
Will let you know if engine "blows"
Dont wait up though
Cheers

NigeK


[This message has been edited by NIGE K (edited 28 March 2001).]

Andrew Timmins

PeteT,

Aldon Automotive sell Motul.

All,

Please take a look at this web page and let me know if you find it helpful.

harrydog

Another word on the benefits of polyolester basestocks as compared to other synthetic basestocks, this from the Redline website. (note: Redline backs up their claims with ASTM standard testing procedures).
"The thermal stability of the synthetic hydrocarbon used in other synthetics is only slightly greater than a petroleum hydrocarbon molecule; however, the polyolesters in Redline are capable of at least an additional 100 degrees F before breakdown."

In another test, oils were subjected to 400 degree F temperatures for 6.5 hours. The 5w30 petroleum oils had an evaporation loss of about 25% while the Redline 5w30 had about 6%.

[This message has been edited by harrydog (edited 31 March 2001).]

druddle

Just as an FYI, Lancaster Subaru of Pangbourne recommended to me to put Esso Ultron 5W40 in my MY01.

Jets1in

Synthetics are a very wide range of base stocks including esters, di-esters, PAO and other such chemicals. CAUTION Polyesters are not compatible with any other synthetics or mineral products. If you use this in your road going car you will need to "fully" remove all mineral / PAO product before adding any polyester product....(note if you change oil normally there is a 5% cross over contamination into the new lube charge).

The logistical disadvantages of using this type of product far outweigh any protection or performance benefit (if any). For example If you need to top up with some more oil whilst on holiday or going to see a mate 100 miles from home there is no way you can top up from a garage with any other product.

If you do u will see somthing closly resemebeling butter in your engine......Its a big no no in any road car.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by harrydog:
<B>Those who said to use an oil with a smaller gap (10w30, 15w40) rather than a wider spread (0w40, 5w50) are correct. Even synthetics need to use viscosity index improvers (VI's) to get this large spread. The VI's are less stable under extreme heat and shear stress and tend to crack, or break down, causing sludge and other problems.
Also, not all synthetics are created equal. The best basestocks are polyolesters as compared to the cheaper PAO's. Redline and Motul are the only two brands that I'm aware of that use polyolester basestocks in their oils. They are the best.[/quote]

Mike Tuckwood

What a great thread.

Jets1in.

So anybody using a Polyester Base stock (such as Redline, or Silkoline Pro S) Oil should have a full engine flush at the point of changing to it?

What would the potential consequences of the 5% contamination be if that didn't happen?

Mike.

PeteT

No disrespect Jets1in but surely that's bollocks. I've just looked on the RedLine, Motul, and Silkolene websites and the Demon Tweeks catalogue and there is no mention of this alleged "no mixing" rule.
Anyway I've just emailed the tech departments of all three and I'll post their comments on this thread.

PeteT

Just had this back from Tom Watson at Silkolene UK
"there are no problems with switching from Castrol RS (the oil I am currently using - Pete)to either Silkolene Pro S 10w/50 or Turbolene GTI 15w/50 although if the Subaru is used mainly for road work and not outright competition only, I would recommend that you use the ProS 10w/50".

Looks like I'll be filling up with Pro S at my next service.

PeteT

Just had this from RedLine-
"The Red Line motor oils will mix with other oils without any problems,either synthetic or petroleum oil. You can refill with Red Line without any concern".

And this from Motul-
"The residual oil after a change will have no harmful effects on either the new oil or your engine, the only question is which viscosity you use. The Prodrive Subaru WRT cars use 300v Power 5W40. An alternative is 300V Competition 15W50".

Any comments Jets1in??