Genuine BMW B58TU High Power Spark Plug – 12122455258 – M140i / M240i / M340i / 340i / 440i / X5 40i

The genuine BMW 12122455258 B58TU high-power spark plug is the factory ignition upgrade designed to deliver stable combustion under higher boost and cylinder pressures. Used as standard on higher-output B58TU engines, it’s the recommended plug for Stage 1 and Stage 2 tuned Gen-1 B58 models and a direct OEM replacement for Gen-2 B58TU applications.

Fitment: BMW B58 & B58TU Petrol Models
SKU: 12122455258

Key Features

Genuine BMW High-Power TU Specification

– Factory plug for higher output B58TU engines
– Ideal for Stage 1 & Stage 2 tuned B58 setups
– Proven ignition stability under high boost

Pre-Gapped OEM Design

– No gap adjustment required for standard replacement
– Direct fit into factory ignition system
– Smooth idle and consistent cold starts

Engineered for Turbocharged Conditions

– Handles increased cylinder pressure and heat
– Reduces risk of misfires on tuned vehicles
– Maintains optimal combustion efficiency

The plug is supplied with the BMW preset gap and is commonly used as an upgrade on Gen-1 B58 cars running higher power levels.

Benefits

– Stronger ignition for tuned and stock engines
– Improved reliability at higher power levels
– OEM fit, performance and durability

Fitment

Gen-1 B58 (recommended upgrade for tuned cars):
– BMW M140i
– BMW M240i
– BMW 340i
– BMW 440i

Gen-2 B58TU (direct OEM application):
– BMW M340i
– BMW 540i
– BMW 740i
– BMW X3 M40i / X4 M40i
– BMW X5 40i / X7 40i
– BMW Z4 M40i
– Toyota GR Supra 3.0

(Always confirm via VIN if unsure.)

Installation Notes

– Supplied as a single plug (6 required per engine)
– Recommended replacement interval: ~20k miles on tuned vehicles
– Torque to BMW specification

About BMW Genuine Parts

BMW Genuine ignition components are designed for precise integration with the engine management system, ensuring reliable spark delivery, efficient combustion and long-term performance.