Fluid additives?

[Lander91]

Hello all, I'm interested to know if anyone is using additives.

These can be for engine oil, fuel, front differential & transfer case, transmission or rear differential.

What are you using, for how long and any results to speak of?

[IchBautAuto]

No additives except in the windscreen wash tank. In the older days when oils were mineral based there were some great additives around as people pushed the boundaries. With the newer synthetic oils, you almost need to be an industrial chemist to be sure that your additive isn't reducing your oils overall or specific performance. Poisoning your Cat Converter is one routine outcome. Choose your oil wisely and you won't need anything. My RS4 has 280,000 plus on the clock, still on original K04 turbos making about 450 hp. No record but a great innings. Mobil 1 0W-40 all it's life. Liqui Moly 5w-40 in the '6.

[Mɐʇʇ]

What Tony said.

I never add additives to engine oil, nor do I use flushing oils.
On the the ‘6, a 5w40 505.01 spec is just right.

[steve2003rs6]

About a year ago I had a coolant leak. Took the car to a local vag dealer. Long story short. They wanted to put additive in the coolant in a attempt to cure the leak.
I personally just hate additives of any sort. So never went back to that particular garage again.

[Shoppinit]

Good call. As far as I’m concerned the leak stop additive is a last ditch remedy, short term, for a terminally ill clunker.

[Lander91]

No additives except in the windscreen wash tank. In the older days when oils were mineral based there were some great additives around as people pushed the boundaries. With the newer synthetic oils, you almost need to be an industrial chemist to be sure that your additive isn't reducing your oils overall or specific performance. Poisoning your Cat Converter is one routine outcome. Choose your oil wisely and you won't need anything. My RS4 has 280,000 plus on the clock, still on original K04 turbos making about 450 hp. No record but a great innings. Mobil 1 0W-40 all it's life. Liqui Moly 5w-40 in the '6.

What type of Liqui Moly are you using.

Also thanks gents, great feedback.

[IchBautAuto]

Toptec 4100. It works and meets all the specs which is what matters to me. Certainly no issues with hot runing at speed recently and maybe 50ml used over 3000 Km.

[Lander91]

!!WARNING, OCD CONTENT FOLLOWS!!

Just finished my 2nd oil change since buying the 6. Note I've only done about 500km in the last 13mths of ownership.

The last oil service it had before me used 505.01 Fuchs titan gt1 synthetic oil, and the car had travelled about 2000km since then but the oil was quite dark/black, oil filter was Audi genuine.

Because I'm OCD and there was a deal on Castrol edge fst I decided to do the following:
Drain PO oil and change filter
Fill with suitable flushing oil as existing oil was black and
smelled quite old and 'fuelly'. Take through a few cycles.
Drain and change filter
Fill with fully correct oil till next service (likely in 12mths)
Drain and change oil filter
Fill with "High lubricity" genuine oil G S55502M4 - just to see if
there's any appreciable difference between this and the Castrol

The 'flushing' oil was Valvoline synpower 505.00 and covered about 150km with this. Engine ran fine, oil colour was what you'd expect before the change to the Castrol.

Now, I wasn't going to bother initially but I decided to use liquimoly proline engine flush - yes counter intuitive since this was the whole point of a flushing oil. I didn't think it would do much harm, I'll likely only do 1000km between now and the next service where the Castrol will be drained and replaced with the genuine oil. I was astonished to see the state of the oil once the process was finished. As stated the Valvoline oil was clear, only ~150km travelled before adding the engine flush. It came out just as black as the oil the Valvoline replaced!

Try to pick which one is which in the picture.