NGK Genuine BP6ES Spark Plug - silver/white

Product Information

Mixing spark plug types is not a good idea as they are manufactured with different specifications and compatibility. Hence, if you combine different spark plug types in your vehicle’s engine, you may experience inconsistent performance and efficiency. Boy this plug debate gets bogged down at times and confuses the crap out of most particularly considering our situation re non resistance plugs required and then what heat range plug to use for individual cases?? Both spark plugs are designed with an alumina ceramic insulator that enables them to withstand high temperatures and helps to provide good electrical insulation. However, the BPR6ES insulator is slightly longer than that of the BPR5ES spark plug. Copper Core Trivalent plating is the silver finish on NGK plugs that is specifically developed to prevent corrosion of the bare metal threads and metal surfaces of the spark plug, whilst allowing dry fitment without the need for anti-seize compounds during services. The BPR5ES spark plug is a standard plug size, having a thread diameter of 14mm as well as a thread reach of 19mm. The plug is compatible with a wide range of vehicle engines, including those with electronic ignition systems and others that use carburetors.

Many vehicle owners use BPR5ES spark plugs to fight poor fuel economy issues, as well as acceleration and emissions problems. With older leads the conductor insulation is subject to continual heat and eventually breaks down. Old connectors can have resistance that increases anywhere up to 1350ohms which is getting into the heading for trouble zone. The P in BPR6ES stands for “projected insulator or projected tip.” This type of spark plug has an extended ceramic insulator tip that protrudes further than regular insulator tips in most spark plugs.

Champion RN11YC4, Denso W16EPR-U, and Bosch WR7DC spark plugs are some of the close substitutes for the BPR6ES spark plug. ago under guidance of a local Mercedes Authorised Repair/service Centre the owner "who is also an old school Mercedes fanatic" told me the best now plug to run in our engines is "Beru Ultra-X UX79" Part # 0 002 335 600 The BP6ES spark plug is built with a colder heat range compared to its BPR6ES counterpart, which means that the former is designed with the capacity to dissipate more heat and prevent engine overheating. Since they can dissipate a lot of heat efficiently, most high-performance car owners use BPR6ES spark plugs to manage the high level of heat generated by their engines to prevent overheating. Champion RC12YC and Denso W16EX-U are equivalent to BPR5ES. However, inasmuch as these spark plugs are equivalent with respect to their heat range and physical dimensions, they also have slight differences.

However, the reverse is the case for some spark plug brands (the higher the number, the hotter the plug). If you desire an NGK spark plug to be used in a high-performance vehicle engine, ensure to choose a colder spark plug that can handle the high RPM and loads. What is the proper gap for BPR5ES?I fail then to understand at all why Bosch would recommend using a resistor plug in a W126 application - you are just asking for trouble.