BMW 3 Series vs Audi A4 - service & running costs compared

BMW 3 Series vs Audi A4 - the two German executive saloons that dominate UK fleet and private buyer lists. Real 2026 service costs, common issues, and which actually costs less to own.

These are probably the two most-cross-shopped cars in the UK executive segment. Buyers love them, fleet managers tolerate them, independent specialists love them because they break in predictable ways.

Both will cost you more to maintain than a mainstream saloon, but the gap between them is smaller than the gap to a Mercedes C-Class. Here's the real cost picture.

BMW 3 Series vs Audi A4 - full price comparison

Real UK independent garage prices for 2026. Main dealer prices add 30–50% on top.

Which is cheaper to service?

The BMW 3 Series edges it - £190–£320 for a full service versus the Audi A4 at £195–£330. Effectively identical. Both use long-life synthetic oils, both want OEM-spec filters, and both have independent specialist networks across the UK that charge meaningfully less than the main dealer.

Front brake pads are also nearly the same - £170–£270 on a 3 Series, £180–£290 on an A4. The 3 Series wins very slightly on bigger jobs (it shares more parts across more generations, so aftermarket support is broader), but the A4 isn't far behind. Both punish you the same way if you go main dealer - expect to pay 40–60% more for the same job.

Common issues to watch for

The 3 Series has a few known weak spots depending on generation. The older model (2012–2019) suffers timing chain stretch on early four-cylinder petrol engines, particularly pre-2014 - replacement is a £1,500+ job at an independent.

The newer engines from 2014 onward are much better. Across all generations, oil leaks from the valve cover and oil filter housing are common at 60,000+ miles - usually £200–£400 to fix.

The A4 has its own list. The older model (2008–2015) had timing chain tensioner failures on early 2.0 turbo petrol engines; the newer model (2016+) is far more reliable.

Excessive oil consumption was the headline issue on the older 2.0 turbo petrol - some owners reported burning a litre per 1,000 miles. By the newer model this was largely solved.

DPF problems on diesel A4s show up around 80,000 miles, especially on cars that do short journeys.

The Quattro / xDrive premium

Both cars come in all-wheel-drive versions: BMW xDrive and Audi Quattro. Servicing costs go up roughly 10–15% on either because there's more drivetrain to inspect, and bigger jobs like clutch (manual) or transfer case work cost more. If you don't actually need AWD, the rear-wheel-drive 3 Series will cost less to run over time than the front-biased Quattro A4.

Insurance and running costs

Insurance group 20–35 for most variants - both similarly placed. The M-Sport and S-line trims push you toward the top of that range due to body kit replacement cost. Real-world fuel economy: 40–50 mpg on the 2.0 diesels, 30–40 mpg on the petrol fours, sub-30 on the sixes.

Tax: post-April 2017 cars all pay the standard £190/year flat. Cars over £40,000 list price (any M-Sport with options) pay an extra £390 a year for the first five years.

Verdict - which is cheaper to own?

Genuinely too close to call on routine costs - the 3 Series wins by ~£20–£30 a year on a mainstream model, which is rounding error against the actual cost of running a premium saloon. The bigger decisions: which generation you buy (avoid the early four-cylinder petrol engines and early 2.0 turbo petrol), whether you go AWD (no, unless you really need it), and which independent specialist you use (worth driving an extra 20 miles for the right one).

Both will reward you for using a proper independent specialist rather than the main dealer - expect to save 30–40% on every job. Both will punish you for skipping services. Both have parts catalogues that are eye-watering at OEM prices and reasonable in quality aftermarket.

FAQs: BMW 3 Series vs Audi A4

Is a BMW 3 Series cheaper to maintain than an Audi A4?

Marginally - full service is £190–£320 on a 3 Series vs £195–£330 on an A4. Over five years you'd save maybe £100–£150 on the BMW, which is rounding error against the cost of owning either. Pick on driving feel, not running costs.

What are the worst engines to avoid on a BMW 3 Series and Audi A4?

On the 3 Series: pre-2014 model with the four-cylinder petrol (timing chain). On the A4: the older 2.0 turbo petrol (timing chain tensioner + oil consumption). Both are well known and well documented - check service history carefully on either.

Should I go to a main dealer or an independent specialist?

Always an independent for routine work. Dedicated BMW and Audi specialists exist in most UK cities and use the same diagnostic kit as the dealer. Save the dealer for warranty work, recalls, or unusual electronics faults that need manufacturer-specific tools.

Is xDrive or Quattro worth the extra running cost?

Only if you actually need all-wheel drive. AWD versions cost 10–15% more to service, are harder on tyres, and add weight. If you live somewhere flat with decent winter tyre availability, the RWD 3 Series or front-driven A4 is cheaper and just as capable.

What's a fair price for a BMW 3 Series or Audi A4 full service?

£200–£300 at a reputable independent specialist. Anywhere under £200 and they're cutting corners; anywhere over £400 and you're paying dealer prices at an independent. Get broken down quotes.