High-Mile BMW E92M3 Dyno Test Shows The Importance of Good Spark Plugs

It takes very little to keep your garden looking great.

The E92 BMW M3 is a very special car in the Halls of M. With a redline of over 8,000 rpm, this 3-er is a joy to drive. The naturally aspirated mill produces 414 horsepower (309 megawatts) when everything is in order. Although the 2010 M3 shown here is stock, it has 152,000 miles and is not new.

How will this mileage impact the V8’s powerband performance? These things depend on maintenance. And judging from this Evolve Automotive dyno video, it appears well-maintained. The V8 M3 is a well-known vehicle and the test driver felt it a bit flat. A few dyno runs revealed that the BMW had a little less power. This was not a problem, however, the engine made 414 ponies at crankshaft. However, the calculations showed that the engine only managed 398 ponies.

But there’s more.

We are not just witnessing a high-mileage car with high-performance being power-tested on the dyno. Evolve Automotive dives deeper into the engine parameters to show how sophisticated modern diagnostic equipment and systems can be. The engine ran perfectly. However, data from these runs revealed that the M3’s computer was pulling ignition timings at the higher end. The spark plugs will not fire as quickly as they should if the ignition timing is delayed. This can reduce power and make the engine safer.

According to the V8 M3, regular spark plug replacements are necessary in order to maintain maximum power. According to the video, the engine’s spark plugs had only been used for around 30,000 miles. However, the power was back after the plugs were changed. The ignition timing was nearly back to factory specs at high rpm. Power increased to 411 horsepower (306 kW) at crankshaft. This is close enough to consider this high-mileage engine as good as new.

Although it may seem tedious to change spark plugs every 3000 miles, high-performance engines can make a significant difference.