Description

Original DENSO VXUH22I 5656 Iridium Tough Spark Plug

The DENSO VXUH22I (5656) is part of DENSO’s Iridium Tough lineup, built for petrol engines that call for a fine-wire iridium tip paired with a heavy-duty ground electrode. The result is a plug engineered for dependable ignition and a service life well beyond what standard nickel plugs offer.

At the heart of this plug is a 0.4 mm iridium center electrode. That ultra-thin tip focuses the spark into a tighter, more precise point, which means the ignition system needs less voltage to fire it — and combustion tends to be more consistent as a result.

DENSO’s Iridium Tough line was built with longevity as the priority. Pairing the fine iridium tip with a purpose-built ground electrode lets the plug hold its ignition performance for far longer than a conventional plug would manage.

With a 12 mm thread diameter, 26.5 mm reach, and 16 mm hex, the VXUH22I 5656 fits a specific range of modern petrol engines. You’ll find it used across several Japanese brands — Suzuki, Subaru, Daihatsu, Toyota, Mazda, Honda, and Mitsubishi — though exact fitment varies by engine and model.

 

DENSO VXUH22I 5656 Specifications

Specification Details
Brand	DENSO
Part Number	VXUH22I
DENSO Stock Number	5656
Product Series	Iridium Tough
Spark Plug Type	Iridium
Center Electrode	0.4 mm Iridium
Thread Diameter	12 mm
Thread Reach	26.5 mm
Hex Size	16 mm
Recommended Gap	0.9 mm
Heat Range	22
Seat Type	Gasket / Flat Seat
Ground Electrode	Special long-life design
Resistance	5 kΩ
Terminal	Fixed SAE type
Quantity per Engine	Depends on vehicle
Category	Automotive Spark Plug

 

The DENSO VXUH22I is designed around a compact M12 spark-plug configuration with a fine-wire iridium center electrode. Always verify the exact spark-plug specification against the vehicle manufacturer’s requirements before installation.

Key Features of Genuine DENSO VXUH22I

0.4 mm Fine-Wire Iridium Electrode

The VXUH22I uses a 0.4 mm iridium center electrode. Its extremely fine firing tip concentrates the ignition spark at a small area, helping the ignition system produce a strong and consistent spark.

The small electrode also requires less voltage to initiate the spark compared with a conventional larger-diameter electrode, which can contribute to dependable ignition under different operating conditions.

Iridium Tough Technology

The DENSO VXUH22I belongs to the Iridium Tough range, which places particular emphasis on electrode durability as well as ignition performance.

Iridium has excellent resistance to high temperatures and electrode erosion. This allows DENSO to use a very fine center electrode while maintaining the durability required for long-term engine operation.

Long-Life Ground Electrode Design

A key characteristic of the VXUH22I is its emphasis on reducing electrode wear. The ground-electrode construction is engineered to help maintain the required spark gap and ignition characteristics over an extended service period.

Reliable Ignition

The fine center electrode helps concentrate the ignition spark and can make it easier for the ignition system to initiate combustion.

When the DENSO VXUH22I is installed in an engine for which it is specified, it can help provide:

• Consistent spark formation
• Reliable engine starting
• Stable combustion
• Smooth engine operation
• Consistent ignition performance

Benefits of DENSO VXUH22I

When the VXUH22I is the correct spark plug for the engine, it can help maintain:

• Reliable cold and warm starting
• Consistent ignition
• Smooth engine operation
• Stable combustion
• Good throttle response
• Efficient fuel combustion
• Reduced risk of ignition-related misfire caused by worn spark plugs
• Long-lasting electrode performance
• Stable spark characteristics over extended mileage
• Reliable performance under normal and demanding driving conditions

The actual service life of a spark plug depends on the engine, ignition system, driving conditions and manufacturer’s maintenance schedule. The VXUH22I 5656 should therefore be replaced according to the vehicle manufacturer’s recommended interval.

DENSO VXUH22I 5656 Applications

The DENSO VXUH22I is used in selected petrol engines from Japanese vehicle manufacturers. Application data associates this spark-plug specification with vehicles from manufacturers including Suzuki, Subaru, Daihatsu, Toyota, Mazda, Honda and Mitsubishi.

Because spark-plug specifications can change between engines, model years and markets, the vehicle’s engine code and original spark-plug number should always be checked before ordering.

Suzuki

The VXUH22I specification is particularly relevant to a number of Suzuki compact and kei-car applications, including selected:

• Suzuki Alto
• Suzuki Alto Lapin
• Suzuki Hustler
• Suzuki Spacia
• Suzuki Wagon R
• Suzuki Wagon R Stingray
• Suzuki Every
• Suzuki Carry
• Suzuki Swift
• Suzuki Baleno
• Suzuki Escudo
• Suzuki X-Bee

Specific applications depend on the engine and model generation. Certain Suzuki kei-car engines, including selected R06A and R06D applications, are associated with DENSO fine-wire iridium spark-plug specifications.

Subaru

Selected Subaru models using compact petrol engines may use the DENSO VXUH22I, including:

• Subaru Chiffon
• Subaru Dias Wagon
• Subaru Lucra
• Subaru Pleo
• Subaru Sambar
• Subaru Stella

Daihatsu

Selected Daihatsu applications associated with this DENSO spark-plug specification include:

• Daihatsu Move
• Daihatsu Tanto
• Daihatsu Mira
• Daihatsu Mira e:S
• Daihatsu Cast
• Daihatsu Wake
• Daihatsu Taft
• Daihatsu Rocky

Toyota

Selected Toyota kei-car applications can also use this type of DENSO fine-wire iridium spark plug, including:

• Toyota Pixis Epoch
• Toyota Pixis Joy
• Toyota Pixis Mega
• Toyota Pixis Space
• Toyota Pixis Van
• Toyota Copen

Mazda

Selected Mazda kei cars equipped with compatible engines may use the VXUH22I, including:

• Mazda Carol
• Mazda Flair
• Mazda Flair Wagon

Applications can include vehicles equipped with R06A and R06D-series 660cc engines, depending on model year and specification.

Why Choose the DENSO VXUH22I 5656?

If your engine calls for this exact spec, the VXUH22I 5656 earns its place with a real set of practical advantages:

• Longer service life — the fine iridium tip and reinforced ground electrode resist wear far longer than nickel plugs, so you’re not replacing plugs as often
• Better fuel efficiency — a cleaner, more complete burn on every cycle means the engine extracts more from the fuel it’s given
• Smoother, more stable idling — consistent spark formation keeps combustion even, cutting down on rough idle or hesitation
• Reliable starts in any weather — the low voltage requirement of the fine electrode makes cold starts and hot starts equally dependable
• Reduced misfire risk — a worn or inconsistent spark is a common cause of misfires; this plug’s durability keeps that risk low over the long haul
• Better throttle response — cleaner ignition translates into a more responsive, direct feel when you accelerate
• Lower long-term cost — yes, iridium plugs cost more upfront than nickel ones, but the extended lifespan usually means fewer replacements and less maintenance hassle over the life of the vehicle
• Consistent performance over mileage — the plug holds its gap and firing characteristics well past the point a standard plug would start to degrade

At 12 mm thread diameter, 26.5 mm reach, 16 mm hex, the VXUH22I 5656 is a precision fit rather than a one-size-fits-all plug — so the payoff above only holds if it’s genuinely the correct spec for your engine.

Before ordering, match it against your vehicle’s model, model year, engine code, and original spark plug part number to make sure it’s the right fit.