Audi A5 Coupe Spark Plugs: Intervals, Fitment & Warning Signs

On the A5, a coil pack replacement on related models genuinely hasn't always fixed a misfire, with worn plugs turning out to be the actual cause.

Generation covered: this guide is for the second-generation A5 Coupe (F5 platform, 2016–2024) — the two-door coupe discontinued when Audi renamed the A4 saloon to A5 in 2024. These are entirely different cars despite sharing a name; if your car is a four-door saloon or estate bought new since 2024, this guide does not apply to it. Check your logbook or VIN if you're unsure which car you have.

Illustration for editorial purposes

A Cheap Part That Causes Expensive-Feeling Problems

Worn spark plugs rarely announce themselves clearly — a slightly rougher idle, a bit less punch off the line — symptoms easy to blame on almost anything else in the engine bay. The part itself costs very little, which makes it an easy one to overlook for far longer than it should be.

Before you buy: plug type and gap specification vary by engine size and generation. Always confirm against your VIN before ordering.

OEM Part Numbers

Accuracy note: confirmed for the 2.0 TFSI turbo petrol on early-to-mid F5 cars (2013–2016 build) — later cars may use a superseded reference. Diesel variants don't use spark plugs at all.

2.0 TFSI, 2013–2016	Audi OEM: 06H-905-601-A (Bosch or NGK, both genuine factory-fit options)
Recommended plug gap	0.028in factory spec for turbocharged engines — NGK aftermarket equivalents are sometimes pre-gapped wider at 0.032in, so check before fitting

Audi sourced this plug from both Bosch and NGK during production, and either is considered a genuine factory-correct replacement — pick based on preference rather than worrying about which one your car originally had. If your engine has been remapped or tuned, discuss the correct gap with a specialist rather than assuming the standard factory setting still applies.

What They Do

Spark plugs ignite the compressed fuel-air mixture inside each cylinder, and their condition directly affects combustion efficiency, fuel economy and smooth running. Petrol engines rely entirely on them; diesel engines don't use spark plugs at all, relying on compression instead.

Fitment & Compatibility

Plug type, gap and thread specification differ between engine sizes and generations of the A5 Coupe — copper, platinum and iridium plugs are not simply interchangeable upgrades, since the correct type depends on your specific engine's design. Always confirm the exact specification for your engine before ordering. Whether you're sourcing a replacement spark plugs for your Audi A5 Coupe from a dealer, specialist, or online marketplace, always check compatibility against your registration or VIN before buying.

Warning Signs & Replacement Interval

Symptoms Worth Acting On

Rough idle or engine misfire — often the first noticeable sign, especially at idle or under light load.
Reduced fuel economy — worn plugs cause less efficient combustion, quietly increasing fuel consumption over time.
Difficulty starting — particularly noticeable in cold or damp weather once plugs are significantly worn.
Check engine light with a misfire code — a definitive sign worth acting on rather than ignoring.

Standard copper plugs typically need replacing every 20,000-30,000 miles, while iridium or platinum plugs can often go 60,000-100,000 miles — always check your specific engine's schedule rather than assuming a generic interval.

DIY Replacement Difficulty

This is generally an easy-to-moderate DIY job on most engines, requiring a spark plug socket and a torque wrench to avoid over-tightening, which can damage the cylinder head. Some engine layouts have easier access than others — V6 or V8 engines with rear-bank plugs can be considerably more involved than a straightforward inline four. Expect 30 minutes to an hour for most four-cylinder engines.

A Genuinely Useful Piece of Context Worth Knowing About Persistent Misfires

If a coil pack replacement hasn't resolved a persistent misfire, this is genuinely worth knowing: documented cases on related Audi models describe a coil pack replaced for a specific cylinder's misfire, only for worn or carbon-fouled spark plugs to turn out to be the actual cause instead.

A genuinely useful, money-saving diagnostic technique worth trying first: swapping a suspect coil with the coil from a different cylinder and seeing whether the misfire follows it is considerably cheaper than buying a new replacement coil outright on a hunch.

It's also genuinely worth knowing that failing to fully click the rear coil pack connectors back into place is a frequently documented cause of a misfire appearing immediately after fitting new coils, and that mixing coils from different sources rather than replacing them all together has been documented causing ongoing misfires.

OEM vs. Aftermarket

Reputable aftermarket spark plugs from established brands are widely regarded as equivalent to OEM parts, provided the type and specification match exactly. This is one part where sticking to the manufacturer's specified plug type matters more than the brand name on the box.

More Audi Spark Plugs Guides

The same part, covered across other Audi models.