Genuine BMW B58 TU/B58TU High Power Spark Plug Stage 1/2, OEM 12122455258 Fits M140i M240i M340i 340i 440i 540i 740i X5 40i X7 40i Z4 M40i Toyota Supra A90

BMW OE B58TU High Power Ignition Plug - Part No. 12122455258

Looking for a reliable ignition upgrade for your turbocharged six-cylinder B58 engine? This BMW original equipment B58TU high power ignition plug, part number 12122455258, is a proven choice for remapped and stock vehicles alike. It is the same factory unit used by BMW on higher output B58TU applications, giving excellent combustion stability under increased boost and cylinder pressure. Ideal for Stage 1 and Stage 2 calibrations and a smart option when running an uprated turbo.

We have installed these on our own builds and for many customer cars with superb results. Expect crisp throttle response, smoother idle quality and reduced risk of misfire when pushing performance. Pre-gapped by BMW for direct fitment and easy servicing.

Key benefits

• Genuine BMW OE component for exact fit and dealership-level reliability
• Supports remapped engines and higher boost pressure on B58 and B58TU platforms
• Strong, consistent ignition under load for tuned road cars and daily drivers
• Factory set gap - install and go with no guesswork
• Excellent cold start behaviour and smooth running
• Trusted by enthusiasts and tuners seeking an OEM-plus upgrade

Fitment highlights

Perfect for B58-powered performance models including:

• M140i F20 F21
• M240i F22 F23
• M340i G20 G21
• 340i F30 F31
• 440i F32 F33 F36
• 540i G30 G31
• 740i G11 G12
• X5 xDrive40i G05
• X7 xDrive40i G07
• Z4 M40i G29
• Toyota GR Supra A90 3.0

BMW also lists this plug for a wide range of additional petrol models and years, including selected 2 Series F45 F46, 3 Series G20, 5 Series G30 G31, 6 Series G32, 7 Series G11 G12, i8 I12 I15, X1 F48, X2 F39, plus MINI F54 F55 F56 F57 F60 within the dates shown by BMW. If you need a deeper compatibility check, we can help before you buy.

Important notes

• Designed for B58TU applications and widely used on Gen 1 B58 engines as an upgrade for Stage 1 and Stage 2 maps or bigger turbos
• Sold individually - most straight-six B58 engines require 6 plugs for a complete set
• BMW part number: 12122455258 (also written as 12 12 2 455 258)

Need us to confirm fitment?

Unsure if 12122455258 is correct for your vehicle? At checkout, add your UK registration or the last 7 of your VIN and we will verify compatibility so you order with confidence.

Professional fitting

Want it installed properly the first time? Book fitting with MJ Modifications in Warwickshire. Email info@mjmodifications.co.uk for a quote and availability.

Manufacturer and warranty

Manufacturer: BMW

Warranty: Two years for UK customers and one year for international customers, when a valid VIN is supplied at checkout on compatible vehicles.

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