Audi has built its reputation on a specific kind of quality. Not the sporting character of BMW, not the outright luxury of Mercedes — something more precise, more considered, more Nordic in its emotional temperature. The A4 is the most complete expression of that identity in Audi's mainstream range, and on the used market it delivers that character at prices that make the comparison to a Golf almost absurd.
The interior is where this argument is won. Audi's material quality and assembly precision in the B9 generation (2015 onwards) is genuinely outstanding — the kind of quality that makes competitors feel slightly rushed in comparison. Soft-touch surfaces where there should be soft-touch surfaces, switchgear that operates with consistent weight and feel, an absence of rattles and squeaks that speaks to how the car was put together rather than how it was designed to look.
But the interior quality is only the selling point if the mechanicals support it. And some of Audi's engine choices from this era have a specific problem that costs buyers money who didn't know to look for it. This guide starts there.
B8 or B9?
The B8 (2008–2015) is the previous generation and available at significantly lower prices on the used market. These cars are now fifteen years old at the older end, and while the quality of construction has meant many have aged well, the tech feels dated against current alternatives and some of the early TFSI petrol engine problems were more pronounced in this generation. The 2012 facelift improved the interior and infotainment, and post-facelift B8 cars are more compelling at the prices they now reach.
The B9 (2015–2023) is where most buyers should be focused. The interior quality leap over the B8 was significant — the MMI interface became genuinely usable, the virtual cockpit digital instrument cluster (optional, then standard on higher specs) is excellent, and the material quality reached a level that competes with the C-Class and 5 Series without apology. The 2019 LCI (facelift) improved the infotainment further and standardised some tech that was previously optional. A 2019–2022 B9 is the most well-rounded used A4 available.
The engine question — and the TFSI oil issue
This is the most important section for anyone looking at a petrol A4.
Audi's 2.0 TFSI petrol engines have had a well-documented oil consumption problem that affected a proportion of cars — particularly the EA888 engine family used across the Volkswagen Group range. Some engines consumed oil at a rate that required topping up between services, and in more severe cases developed carbon build-up and piston ring wear that progressed to engine damage if not addressed.
The problem was more prevalent in earlier production engines — broadly, pre-2012 — and was progressively addressed through revised piston ring specifications and oil control improvements. Later B8 and most B9 cars are not affected to the same degree. But the concern doesn't disappear entirely until you've confirmed the service history shows no pattern of top-ups or oil-consumption-related work.
What to check on any TFSI petrol A4: pull the dipstick at the viewing before the engine is started. Look at the level and the condition of the oil. If the level is notably low on a car that's recently been serviced, that's a concern. Ask specifically whether the previous owner needed to top up between services, and look at the service history for any patterns of early oil change or consumption-related notes.
On B9 cars from 2019 onwards, the EA888 Gen 3B engine addressed the worst of the historical issues. These are more reliable in this specific respect than earlier TFSI units, and buying a later B9 2.0 TFSI removes most of the risk.
Now, to the actual recommendations:
The 2.0 TDI diesel (150PS or 190PS) is the engine that sidesteps the TFSI concerns entirely. The 150PS is adequate; the 190PS is the one worth targeting — it makes the A4 feel properly effortless at motorway speeds and doesn't feel overworked under load. Economy on longer runs is genuinely impressive for a car of this size and quality level. For high-mileage buyers, the TDI is the obvious choice, and Audi's diesel has a good reputation in service when driven on appropriate journeys.
The 2.0 TFSI 190PS on B9 cars from 2019 onwards is the petrol to go for once the generation and year are confirmed. Smooth, refined, and with the oil consumption history largely behind it on later cars.
The 3.0 TDI and S4 variants are for buyers who want more from the A4 — the 3.0 TDI in particular combines executive car refinement with a delivery that makes the car genuinely quick in a way the 2.0 units don't. These cost more to buy and more to run, but at used prices they represent remarkable value for what they deliver. The S4 with its 354PS turbocharged V6 is a properly fast saloon that still manages to feel understated.
Quattro or front-wheel drive?
Most A4s were sold with front-wheel drive, and for most buyers that's fine. Quattro adds grip, particularly in adverse conditions, but also adds weight, complexity, and cost. The rear-biased torque distribution that quattro delivers is more relevant on the performance variants than on the everyday 2.0 TDI. Front-wheel drive A4s are more common on the used market and typically priced lower, which often represents better value.
If you regularly drive in adverse winter conditions, or you're buying a 3.0 TDI or S4 where the extra power benefits from the additional traction, quattro makes its case. For a 2.0 TDI that will live on motorways, it's largely optional.
What goes wrong
TFSI oil consumption. Already covered above. The single most important engine-related check on any petrol A4.
Timing chain on older TFSI engines. Earlier 2.0 TFSI units in B8 cars had a timing chain tensioner that could fail prematurely, causing a rattle on start-up that's the warning before a more serious problem. On later cars this was improved significantly, but any B8 petrol with high mileage and incomplete history deserves a cold-start inspection specifically listening for chain noise.
DSG hesitation on S tronic automatics. The dual-clutch transmission on lower-power A4s exhibits the same low-speed hesitation that affects Volkswagen Group automatics broadly. It's most noticeable in slow urban traffic and was addressed through updates in later cars. Test any S tronic A4 at parking speed before committing.
Electric parking brake on B9. A small number of B9 A4s developed faults with the electronic parking brake — the most common symptom being the brake failing to release cleanly or requiring a Audi VCDS reset. It's not universal but it's consistent enough to be worth checking during the test drive.
MMI screen and Virtual Cockpit on B8. The pre-B9 MMI system can develop dead pixels or a laggy response on higher-mileage cars. The Virtual Cockpit digital instruments on B9 cars are largely robust but worth testing fully during the viewing.
What you should actually pay
- B8 2.0 TDI (2012–2015): £8,000–£14,000
- B9 2.0 TDI (2015–2018): £14,000–£20,000
- B9 2.0 TDI LCI (2019–2022): £19,000–£27,000
- B9 3.0 TDI/S4 (2016–2022): £22,000–£35,000
Full Audi main dealer service history adds meaningful value on the A4, as it does across the premium German segment. The brand's own service records are comprehensive and verifiable, and a car with documented dealer history is a substantially more confident purchase than one with a mix of independent stamps.
Before you see it
Check the MOT history. Then, for any petrol A4, plan to pull the dipstick at the viewing before anything else. Check the mileage progression for consistency and look at any advisory items relating to the engine or drivetrain — they tend to be early indicators of what's coming rather than isolated observations.
Check the MOT history before you go →
Free MOT checker at AllCarsUKRegistration plate only. Every test, advisory, and recorded mileage. Free, no account needed.
On the test drive: test the S tronic specifically at low speed in a car park if it's a dual-clutch automatic. On a diesel, get it onto a motorway and let it breathe under load — that's when any DPF stress reveals itself. Test the MMI and Virtual Cockpit thoroughly. And sit in the rear seats — the B9 A4's rear passenger space is one of the class benchmarks and it should feel generous.
Should you buy one?
A 2019–2021 B9 A4 2.0 TDI 190PS in S line or Sport trim, full Audi service history, clean MOT, documented without oil consumption history: one of the best-value executive saloons on the used market. The interior quality sets a standard that justifies the slight premium over a 3 Series or C-Class at equivalent age and mileage, and the TDI diesel with confirmed history is not the worry that the TFSI petrol can be.
Get the generation and the engine right and the A4 is hard to argue with. Get either wrong and the interior quality becomes the consolation for what's going on underneath.
Also see: BMW 3 Series Buying Guide | BMW 5 Series Buying Guide | Mercedes C-Class Buying Guide