Oil recommendations and questions here - The Definitive S2 Oil thread

[oilman]

Hi

Yes, harmful to the cat as well as fouling of plugs. Once you get past about 1400ppm there is no benefit in higher ZDDP levels anyway.

Cheers

Tim

[PRY4SNO]

Excellent, thank you. Your information mirrors my own reading on bobistheoilguy forum.

Are you able to provide a list breaking down the ZDDP and/or zinc/phosphorus content of the oils you sell? I'd be interested to know which brands are on the higher range.

[oilman]

Hi

A lot of oil companies don't release the ZDDP content of their oils, they just say it's one of the many additives that protect the engine. They are right about that, ZDDP is the only one that gets mentioned, but there are others like ZDDT which do the same job.

All I can really say is that the top end ester based oils tend to be about 1200-1400ppm.

www.opieoils.co.uk/c-953-ester-synthetic.aspx

Cheers

Tim

[AndyP]

Is ZDDP the stuff they use in friction reducers like ZX1?

[oilman]

Hi

I think they use chlorinated paraffins, or it might be teflon. I can't remember for sure, but 99% sure it isn't ZDDP. ZDDP forms a sacrificial layer, so that wears away instead of the metal, rather than reducing friction.

Cheers

Tim

[Jack4688]

Hi

I would use a 5w-40 synthetic.

http://www.opieoils.co.uk/c-656-5w-40.aspx

Out of those, the best ones are the Fuchs/Silkolene Pro S, Millers CFS/CFS NT, Motul Sport/300V, Red Line and Gulf Competition. The Motul 8100 X-Cess, Millers XF Longlife, Fuchs GT1 XTL/Supersyn, Gulf Formula G/ULE, Shell Helix and Mobil Super 3000 are good, cheaper alternatives.

Cheers

Tim

Thanks, any recommendations for an oil flush product?

[oilman]

Hi

Generally, don't use one, unless the engine is a horrible mess. Best thing to do is get some cheap 10w-40, put it in for a day or two and let the detergents in that gently clean it. Then replace it with the good, new oil and everything should be nice and clean.

Flushes can be very harsh and there is also the risk of some flush being left in the engine and ruining the new oil.

Cheers

Tim

[Jack4688]

Thanks for the tip!

[Ilkorin]

Hi Oilman,

Would be very interested in recommendations on engine oil and gearbox oil on my cabrio:

Make:Audi
Model:80 Cabriolet
Year: 1998
Engine type: 2.8 12v V6 (AAH)
Performance modifications: small engine tweaks, but mostly stock
Driving style: road cruiser
Any other information that may be relevant: 12v V6 AAH has an oil/water heat exchanger so due to driving style oil rarely gets above coolant ~100C. Gearbox is 5spd FWD

Currently running 10W40 Mobil super 2000, and standard old gearbox oil (from '98!) - I'm interested what scope there is to run lower viscosity on both oils for fuel economy and what gearbox oil to use for synchro life.

Also interested in friction modifiers and which manufacturers use them / if they are worth having at all?

[oilman]

Hi

The original grade for the engine is 15w-40, but things have moved on a bit from that, so a 5w-40 or 10w-40 makes sense. If you are looking to reduce fuel consumption, I'd go for the Millers Nanodrive oils, the CFS NT 5w-40 being the best one, followed by the XF longlife 5w-40 and then the EE 10w-40.

http://www.opieoils.co.uk/c-2021-mil...rive-oils.aspx

Going for a thinner grade, like 5w-30 is likely to lead to higher oil consumption.

The standard gearbox grade is a 75w-90 and you could try the Millers Nanodrive oils for that as well (CRX NT and EE).

http://www.opieoils.co.uk/c-673-75w-90-gear-oil.aspx

I wouldn't think there would be an issues in using a good 75w-80, such as Fuchs Sintofluid or Red Line MTL instead though. They are a little thinner than the standard grade, but are good enough quality to still protect properly.

http://www.opieoils.co.uk/c-670-75w-...ion-fluid.aspx

It might also help to use something like the Millers Ecomax to help with economy, but results vary from car to car (I use the diesel one and gained a couple of mpg, others have used it and got no gain).

http://www.opieoils.co.uk/p-60223-mi...treatment.aspx

I would not advise using aftermarket oil additives, many of them are just a waste of money, a few are harmful.

http://www.opieoils.co.uk/t-car-engi...explained.aspx

Sometimes friction modifiers are useful (if a car has a LSD in the gearbox for example), but using them in a gearbox can lead to poor gear changes as they tend to hinder the synchros.

Cheers

Tim

[Ilkorin]

Thanks for the detailed reply - engine oil choice makes good sense, would there be any shift quality effects using the thinner gearbox oil?

[oilman]

Hi

The thinner gear oil should make the gear changes easier.

Cheers

Tim

[URSIMPO]

Hi,
What oil for an Audi S6 (2.2 5 cylinder)? Engine full rebuild about 5k miles ago (but it's been sat a few years), and running about 400-415hp.
The engine builder used Castrol 10w 60 - and swears by it. Should I use this again or look else where?
Am looking to recommission the car (as it's been sat), so also want to change:
gearbox oil
brake fluid
power steering fluid*
diff oil*

*should these be changed?

What oils can you recommend?

thanks

[oilman]

Hi

The Edge 10w-60 is a good oil, but I would say a 10w-50 is a better option for it as it will flow faster.

http://www.opieoils.co.uk/c-659-10w-50.aspx

The Nanodrive CFS is, on paper, the best oil available, but the Pro S, Red Line and CFS are really good oils, so all are good choices for your car.

I would use a 75w-80 for the gearbox and the best proven options are the Red Line MTL or Fuchs Sintofluid. The Millers TRX 75w-80, Valvoline and Motul Motylgear are good alternatives.

http://www.opieoils.co.uk/c-670-75w-80-75w-85-mtfs.aspx

The best fluids for the brakes and clutch are the Castrol SRF, Motul RBF660 and Gulf RF1000. The Motul RBF600, Gulf RF800, Millers 300 Plus and Fuchs Pro Race are close to those, but don't have quite as high boiling points. In reality, they are overkill for road use though. The next step down (in performance terms), but still an upgrade over standard are the Gulf Racing 5.1, Motul DOT 5.1, Pentosin Super DOT 4/Super DOT 4 Plus and Castrol React Performance. Any of the other DOT4 fluids we have are fine to use as a standard choice.

http://www.opieoils.co.uk/c-450-brak...tch-fluid.aspx

This is ideal for the power steering

http://www.opieoils.co.uk/p-60197-fu...lic-fluid.aspx

I would use a 75w-90 in the diff.

http://www.opieoils.co.uk/c-673-75w-...ion-fluid.aspx

The Fuchs Syn 5, Millers CRX, Red Line 75w-90 GL5, Motul Gear 300 and Gulf Competition are ideal for the diff. The Fuchs Sintopoid, Castrol Syntrax Longlife, Millers TRX, Motul Motylgear, Mobil SHC and Gulf Syngear are also good choices.

All oils break down over time due to oxidisation of the additives, so if the oils have been in there for a while, I'd say it's worth changing them for peace of mind.

Cheers

Tim

[Pirvu Eugen]

Hi Tim! Sorry for bothering please!
I have a 6 speed gearbox DPJ from an 1997 A6 and I need oil.
Wich is the best? MT90 from redline? The oil was red in colour at the time I took the box out.
Thank You!