Optimus

Like most ECUs, they are Mostly now all locked down under the guise of emissions, so conventional tune ups barely let you touch anything. What you need is new firmware/hardware and I’d say Syvecs is probably the best suited for VAG. Syvecs is a full standalone ECU with its own firmware and software, so you’re not fighting the factory firmware. It gives way more control over timing, fuel, boost, VVT — basically everything the OEM won’t let you touch. People even use it to run engines on completely different manufacturer platforms Mercedes engine in a Range Rover, Ferrari engine and gearbox in a Mazda the wild list goes on. It’s the only way to go twin turbo on the V10 VAG group engines. It’s not cheap, but if you want proper control on a locked ECU, it’s basically the only option for tuning and if your going to spend the money your going to go big or go home.

I have never got anything near to mid 50’s in day to day driving unless on long distance motorway trips. I usually average 42-47mpg. Mixed bag of driving dual carriage ways, towns and villages. I always leave in auto drive select and never eco.

For context what mileage and age of vehicle? though the common conception is glow plugs never need to be changed until broken this is not true from a mechanics opinion. the constant hot and cold expansion as well as metal on metal corrosion can cause them to seize in place. Rule of thumb for most cars is every 120,000km (100k miles) or 5 years to avoid large repair bills. labour can and will vary but as a rough estimate I’d expect 1-2 hours plus parts. You should never replace 1, replace all 4. it’s just common for running issues after this or the others to start playing up not long after if you don’t replace all at the same time. If they don’t come out easily expect 3-4 hours labour.

What Model year - I’ve been having a nightmare looking through used S6 savants trying to find full options and they all have FBSW but say ‘adaptive cruise control’ which i keep thinking they have it wrong. Assuming the newer models now have it with?

Are you talking about two different models here? The 50TDI is not the same as the 40TDI there has always been a software patch for the 50TDI in fact it was known to be worse until this patch for the auto boxes. The 40TDI is a manual dual clutch with automatic selector. This issue is still very much prevalent and has been no ECU/Drivetrain software updates specifically for hesitation on pull away (least I’m aware of?).

Unless the service plan is through VWFS (Volkswagen financial Services) I wouldn’t bother. the T&Cs through this service plan scheme ensure any dealer network franchise coverage as well as additional leverage to resolving complaints or defects thereafter a service. having worked in the motortrade I have sold used car service plans; you often read genuine parts and this is not always the case and I have often seen inspections and oil changes being done in 20 minutes or less. The oil gets changed but the inspection in my opinion is not the same. Main dealer networks rely on high turn over of customers in and out the doors. They pay their workshop staff bonuses based on speed not quality. echoing what others have said id personally put money away and chose an independent specialist where your get main dealer experience and better value for money, in most cases.

If the oil complies with the following specification then yes. Applies to diesel engines: Standards: VW 507 00, ACEA C3, ACEA C4 or API CK-4. All viscosity classes of these standards are allowed. 5w-30 and 0w-30 VW507 00 (low ash) oils are fine. 5w is slightly higher viscosity then 0w but both are acceptable. Audi dealerships tend to use 5w-30 for servicing as it’s cheaper per barrel. I tend to prefer oil changes being down with 5w-30 and top us 1ltr with 0w-30. Whilst it’s probably negligible difference in reality. I believe as the synthetic oil breaks down due to heat and carbon deposits etc. adding low viscosity oil during top ups in between servicing I find improves overall efficiency. It’s normally towards the end of the service period where I see a drop off of mpg where it’s normally 50-56mpg I used to get around 42-47mpg with my oil top ups it’s now between 45-51mpg for the same journey/time.

Its unlikely repairs can be made, a lot of the auxillary engine parts manufacturered to acheive low emiision ratings have become so over complicated that to take it apart and recondition parts the labour to do so is two-thirds of the cost to replace it. Its intentional, car manufacturers are selling less cars today because the cost to make them has gone up. they are recouping reduction of new car sales in parts. This has been going on for the last 3 decades. Google wet timing belts.... which now seem to be going into nearly every vehicle. A rubber belt that deteriotates submerged in oil and carbon based chemicals added with heat alter the structure of the rubber belt overtime/use... They typically last long enough for the warranty to go by but not much longer.

Personally id close the post entirely should anyone genuinely wish to sell a vehicle the best place to do so is using the appropriate market places in which provide buyer and seller protection at their own risk....

expensive car cheap windscreen - sounds about right

Hi all, i do a lot of motorway mileage in my A6 and covered combined between current and previous A6 around 50k miles. one thing that screams out to me is how unlucky I am with stones and debris hitting the windscreen. My previous A6 C8 I had a new windscreen due to a chip manifesting into a crack on impact and the screen being replaced. My current has had 2 chips one repaired but seems to be cracking and the 2nd chip centrally in the screen crack on impact. Is it the angle of the windscreen prone to slight impact damage or is it the way in which they are made they just seem to have barely any resilience to impact damage. for comparison my 20212 VW Passat had well over a 100k miles and never had to replace the windscreen for cracks and I had probably around 4 stones lobbed that left damaged (the sound was like being shot at) and 3 that skimmed and left only a small dent in the glass. I've drawn conclusions that its either; - design (elevation of glass) - product quality (poor lamination?) - bad luck? For sanity reasons I’m just curious what others have experienced in all my cars I’ve owned I’ve only ever had to replace 5 windscreens and 2 of those are for this model of vehicle.

Not to be captain hindsight here but this is due to lack of awareness from the garage in hand. They could of instead of saying seized as a reason for failure could of said bearing failure. Pump bearings fail which cause the seal to perish which causes loss of fluid which then works its way into the bearing casing and causes the seizing or binding of moving components from rust. the reason for failure is the aftermath of the initial failure which was the bearings; Which would have been covered under the extended warranty IF the mileage was under 100k or before the due date for camblet change mileage/time (this is common for most typical extended warranty policies). I used to work in the motortrade and if you have someone looking out for the customer, which i always tried....READ the small print on their behalf. This would be lazy service on their part or it may be the warranty rates for being paid for the part and labour were terrible and they just didnt want to be of service.

Hi everyone i have got a rather irritating sound from the engine bay. It is not always present or audiable and can be replicated but isnt consistent in loudness or tone or at all during replication. This sound that i can describe as air passing through a plastic cylinder or being squeezed through. Similar to when you are pumping up an air bed and the air is forced through makes this bird like noise. It can be replicated only by pulling away under acceleration. - hard throttle, moderate throttle or little throttle replicates the sound but varies in its pitch and loudness. When turning and pulling away it seems to be louder irrespective of the throttle applied. It sounds like a vacuum or air leak, but i cant seem to replicate this when idle and engine bay up its literally when pulling away. this has been a quirk on my car for a while i think even from being purchased, however its actually got worse now, i wonder if anytone elses car does the same thing? Car spec 2024 40TDi Quattro Black Edition

Just to update In true fashion, I had it booked in just before Christmas and it stopped doing its thing right before booking in. it was up on the ramp and it was looked at but didn’t seem to be making any noises at all. it could have been stone in the brake disc/heat shield. It could of been the electronic hand brake not fully disengaging. they lubriated the handbrake cable mechanisms and said to monitor. i now have another issue, but that is another thread…

Glad to hear, just to add. I haven’t topped mine up with oil since 18k I’m now on 25k I literally checked today and it’s just under half way down. I added maybe around 100ml or so and back up just under full line level. It could also be that from factory/ pre delivery inspection/top up the oil wasn’t at the full or even over half way. This could also happen after oil change service.

I’m really disappointed as my order has been suspended and now cancelled by Audi. It was due for delivery March 2025. This was due to shortage of engine blocks. They were supposedly meant to have honoured my order given they have suspended production but it appears it won’t be completed. Gutted! Im looking at used cars but I wanted white with Vorsprung spec. My take on the German estates is as follows, though if there is anything to take from this review/comparison I’m very much an iPhone man when it comes to cars with spec and tricks. Keep it simple. If I have to deep dive menus to turn something on or off it becomes too complicated to just get in and drive. The E class, which came in close 2nd- great engine and transmission, probably the best in terms of overall performance and pick up. it looks very smart and subtle externally. However the interior and cockpit was tacky infotainment was crap and I felt the price tag with the options was overpriced. I think the spec I was looking at was well over £80k. i looked at the BMW 5 series tourer which came last - again great gearbox and engine,it was a serious drivers car by far the most exciting diesel to drive. i took issue with the fact the suspension was always firm and as a daily driver it was too ‘pure’. Option wise tallying up the extras was annoying the interior wasn’t comfortable or sound proofing wasn’t great compared to the other 2. i went with the A6 avant 50TDi initially but this was between model changes 2022-2023 and my order before arriving in the UK succumbed to the flooding in Germany in transit. I had to order again but this time it was a MY24 not 22/23 which meant the only model available was the 40TDi. which hasn’t got any guts in it. So I looked at the hybrid and it felt heavy and clunky and the electric cut in and out was terrible not to mention the range claimed was fictional at best. i still stand and say look wise and interior Audi estates/saloons are way better. The only criticism is that they probably could do with a few more customisation options with regards to the colour and fabric/finishes of the interior. It’s fairly limited. arguably the 50TDi is the better engine for these cars. The S6 initially wasn’t my first choice because I felt the power for the v6 diesel was enough for daily driving the only reason Im in the market for the the S6 was that it probably would hold its value in resale as an estate version in The UK post decline of diesel sales as a desired car there is less of them on the road compared with the RS6. Potentially making it iconic being that they are/were so unpopular of the time being that the previous pedigree had been milder v8 petrol engines.

Hi all, recording this as a current problem in my MY23 Avant TDI40 Quattro. Currently become an issue when reversing at low speeds car has covered 19k miles. Non-obvious symptoms other than someone pointing this out to me in the car park. I can’t hear it in the cabin but it’s coming from the rear of the car not the front. It’s replicated by going forward and selecting reverse and throttle. sound is a distinct crunch/grinding sound only at low speed after selecting reverse. further input after taking it in for diagnosis at main dealer.

I’m assuming from the fault codes this is 7 speed DSG gearbox? if that’s a yes, could be anything. best get it booked in with VAG specialist. common problems are service related and firmware related. When you get to 80k miles you can expect to see wear and tear on clutch packs resulting in communication errors with slippages and coming out of gear and the control unit having a hissy fit.

Even in closed systems low tension oil evaporation takes place when it becomes a gaseous state and be deposited else around the vacuum pipes/inlet manifold etc. evaporation is a thing even in closed systems I won’t go into too much detail but F1 engines burn through oil like crazy something like 3-5litres per race setup. The reason why I draw this comparison is that they specifically use low tension oil types similar to modern emission friendly cars to create less drag on movement parts and increase efficiency. whilst I understand the f1 engines are operating constantly at high rpm and temperature. If you are doing motorway mileages frequently you could be burning off a litre of oil every few thousand miles. i have added 5litres of oil since 0 miles. My TDi 40 A6 has done 17568 miles (28273km) and is 14 months old. Roughly about 40% of my driving time is sat at 60mph+. Journey times averaging 56mins.

https://penriteoil.com.au/knowledge-centre/Miscellaneous/242/what-causes-oil-burning-and-oil-consumption/400#:~:text=Oil burns when at its,valve stems%2C seals and guides. very useful thread about oil usage and degradation. But yes all oil including synthetic evaporates!

My experience working for main dealer and dealing with this issue/concern was that from a technical aspect adding oil for new cars under 6k miles every 2k miles was normal. After 6k miles it seemed to be less of an issue until vehicles got to 80k plus (wear and tear) what I was summarising was that you have a situation where it seemed to be normal expected then it was unusual then expected depending on use age and wear and tear. new vehicles though bedded in at factory to a degree always use more oil then after say 20k miles. the additional point I was making was that the oil in these vehicles is very very thin high viscosity and easily evaporates so factoring this in with usage those who do motorway miles (sustained temperatures) experience higher degradation of oil and suffer the most with oil loss. it is normal to expect to be putting oil in every so often but not if is less as quoted above. the difference between petrol and diesel oil consumption is significant. diesel’s will use more oil then petrol as i understand oil is difference grade and running (internal combustion) temperatures are different. therefor using petrol engines by comparison should be disregarded. The oil consumption is concerning but it is from my experience normal across the board. where it’s more concerning is the difference between extended use and short term use because it seems this is where most people are complaining where there is instances of 3000 mile or less topping up 1 litre of oil as a result of the warning indicator.

I add roughly a litre every 2k-3k miles. I do a lot of motorway miles this is normal to a degree. The oil is very very thin, it’s less durable because of its viscosity. Therefore it burns and evaporates far easier. oil loss is as a result of the above. It’s normal on modern vehicles compared to 10 years ago. new vehicles will burn oil as things settle in piston and cylinder liners including o-rings. Id say this is normal for a new car it wouldn’t be normal after 6k miles to burning through 1litre every 1000-2000 miles what ever the usage.

Wiring loom, battery bank, additional control units etc. I don’t know precise weight but you’d be surprised how heavy wiring looms can be 5kg-45kg

The battery does not provide any propulsion to the drivetrain what’s so ever. it is in function start stop with additional coasting features where the engine will shut off coming to a stop or during a moderate decline whilst descending down a road. I’ll be brutally honest having clocked now over 30k miles in mine. Unless you drive the vehicle in a manner where you are chasing high mpg and progress is not real progress (holding traffic at round abouts) your real world mpg is like mid 40s for a 73 litre tank capacity. the system is a complete gimmick and I’d rather remove the weight and faff of it all o save a 100+kgs.

This has been repaired by the dealer. Im conducting my own drives and reviews to provide feedback whether this has positively effected the mpg and drive of the car.