Spark plug – Mercedes W113 W121 W198 W111 W112 W108 W109 W123 W114

Description

NGK spark plug – affordable alternative to Bosch WR5DC / WR5DC+

This NGK spark plug is a high-quality and affordable replacement for the original Bosch WR5DC / WR5DC+ spark plugs with Mercedes OEM number A0031591403 / 0031591403. NGK is one of the world's leading spark plug manufacturers and is known for consistent quality, reliable ignition, and a long service life.

This spark plug is an excellent alternative to the original Bosch spark plug and is suitable for a large number of classic Mercedes models from the 50s, 60s, 70s, and 80s.

Suitable for Mercedes models

• Mercedes W121 190 SL

• Mercedes W128 220 SE Ponton

• Mercedes W198 300 SL Gullwing
• Mercedes W198 300 SL Roadster

• Mercedes W111 220 SEb Sedan
• Mercedes W111 220 SEb Coupé
• Mercedes W111 280 SE Coupé
• Mercedes W111 280 SE 3.5 Coupé
• Mercedes W111 280 SE 3.5 Cabriolet

• Mercedes W113 230 SL Pagoda
• Mercedes W113 250 SL Pagoda
• Mercedes W113 280 SL Pagoda

• Mercedes W108 280 S
• Mercedes W108 280 SE
• Mercedes W108 280 SEL
• Mercedes W108 280 SE 3.5
• Mercedes W108 280 SEL 3.5

• Mercedes W109 300 SEL

• Mercedes W114 230.6
• Mercedes W114 250
• Mercedes W114 250 C
• Mercedes W114 250 CE

• Mercedes W123 250 Sedan
• Mercedes S123 250 T

• Mercedes W460 230 G
• Mercedes W460 230 G Cabriolet

Suitable for Mercedes engines

• M114
• M115
• M123
• M127
• M129
• M130
• M198

OEM references

Mercedes

• A0031591403
• 0031591403

Bosch

• WR5DC
• WR5DC+

Specifications

1. Part: NGK spark plug.
2. Affordable alternative to Bosch WR5DC and WR5DC+.
3. Mercedes OEM: A0031591403 / 0031591403.
4. Suitable for M114, M115, M123, M127, M129, M130, and M198 engines.
5. Ensures reliable ignition, smooth engine operation, and optimal combustion.
6. Suitable for the Mercedes models mentioned above.

Important

Always check new spark plugs for transport damage before installation. Dented packaging may indicate that the ceramic insulator part has sustained a hairline crack. Damaged ceramic can come loose during use and cause serious engine damage.

Always check the prescribed electrode gap before installation. Even new spark plugs may have a deviating electrode gap during transport or storage. If necessary, carefully adjust the gap according to Mercedes factory specifications.

We recommend replacing spark plugs preventively every 8 years or 30,000 kilometers, whichever comes first. Even in vehicles that are driven infrequently, the electrodes and insulation material can deteriorate due to aging, which can lead to a weaker spark, rough engine operation, higher fuel consumption, and reduced cold starting performance.

For optimal performance, we recommend always replacing spark plugs as a complete engine set. Simultaneously check the condition of the spark plug wires, distributor cap, and distributor rotor to prevent voltage loss and ignition malfunctions.

Always check before purchase and installation whether the part is suitable and equivalent based on photos, description, and specifications; installed or used parts cannot be returned.