Hi all,

While not a technical question, it might be about time I change my B8 V6 3.0L with 85k miles, to be fair, it still looks brand new and drive very well (some rattling in the doors and that's it really). While I can keep it longer, I'm wondering what would be a good equivalent I could replace it with.

I do enjoy the torque of the diesel and the power at low rpm when you need it

I've been thinking of a 2021 B9 S5 to replace it (As I believe they also have a diesel engine). I'd love some thoughts if someone had to make this decision as well? 

Thanks for you help. 

Edited September 19, 2025Sep 19 by Oxylis
Edit: Said B10 S5 but meant B9 S5

Haven't got a personal experience but I'm guessing you've checked the buyers guides on YouTube? 

Hey, I did a few yes, quite a lot of opinions but often creators do try so many cars they are comparing with many different models. I was hoping someone might be (or has been) in a similar situation

On 2013 A5 you’re possibly still on Euro 5 diesel? I currently have B9 A4 Allroad with 3.0 litre (272PS) engine which has more than enough power.

Your current car will be coming up for 12 years old and 85k miles. That’s nothing for a diesel, but jumping to the newer technology, plus the cost of a 2021 S5 model should be straight forward as long as the servicing for the last 4 years has been top notch. If it’s been on long service regimes, every 18k miles, then walk away.

I’ve read a few of the reviews on diesel S4 which I assume is same engine in S5 and they were very complimentary. That said, they are complicated, mild hybrid system, AdBlue as it’s Euro 6.

Obviously test drive one, but more importantly, if it’s sold via Audi franchise, then get their extended belt and braces extended warranty. If it’s sold via second hand retailer, then I’m sorry their warranties are underwritten by market and have a lot of exclusions, and are part specific, and daft inclusions such as service every 6 months or void.

Also check out VAG Technic on YouTube. Constant stream of cars in, especially B9 S4 with issues such as needle bearings on rocker arms, this is on petrol models, but they’ve had diesel SQ5 TDI that needed engine rebuild. This S5 (17-plate) petrol diesel didn’t make the cut. 

 

S5 will have 8-speed Tiptronic gearbox, so practically bullet-proof.

Good luck with whatever you decide.

 

Hey @spartacus 68thank you very much, this is very useful!

 

I completely forgot about ULEZ as well since it’s on auto debit 😩

 

will check all of it out now, really appreciate thorough details and warnings!

AdBlue is something to be aware of, as tanks have inbuilt pump and level sensor. If they go they are expensive. I put in Forte anti-crystal every AdBlue top up. Run on premium diesel and change oil and filter every 5-8k miles, fuel filter every 20k miles. OTT, possibly. But I don't want to visit an Audi dealership any time soon.