2020 test5 productsAuto Parts & Repair
Which Spark Plugs Brand Wins?
We compared 5 spark plugs options head to head. Pulstar came out on top. See the measured results, the runner-up, the budget pick, and a link to the full test video.
The measured results
Every number below is read straight from the test. Scroll sideways to see all measurements. Products are listed in the order they finished.
| Product | Flame/combustion visual test | Fuel efficiency, no load (runtime on fixed fuel) | Fuel efficiency, under load (runtime on fixed fuel) | Go-kart race result |
|---|---|---|---|---|
| 1Pulstar | seemed to provide a very immediate and intense combustion, even though it has a side electrode it didn't seem to have any negative impact; provided a more immediate and intense burn compared to the E3 as well as the other spark plugs tested, though narrator notes this observation is subjective | a little over 46 minutes (grouped with the E3 in this recap statement); some bluing observed on the metal tip of the spark plug afterward | outlasted the E3 by around 10 to 12 seconds (E3 was about 36 minutes and a little over 50 seconds, so Pulstar landed a little past that) | installed in the go-kart for the final race after being judged the best performer; go-kart hit 31.2 mph in 27 seconds, a new top speed for the go-kart on non ethanol gasoline, but still lost the race to the farm vehicle which finished in 21 seconds at 49 mph |
| 2E3 | each combustion event seemed slightly different from the next, similar to the Autolite, but seemed to provide a slightly more consistent symmetrical flame curl pattern than the Autolite | about 46 minutes 31 seconds (45:16 baseline time to beat plus about an extra 1 minute 15 seconds) | about 36 minutes and a little over 50 seconds (35:35 was the time to beat), described as very impressive | not tested |
| 3NGK Iridium | not tested | 46 minutes 7 seconds, still not as long as the E3 or the Pulstar | transcript says '6:31 with the NGK Iridium'; this is almost certainly a dropped leading digit from a longer time (likely around 36:31 given the no-load result and the other loaded times in the 35 to 37 minute range), kept verbatim and flagged rather than corrected | not tested |
| 4NGK Copper Core | used as the baseline reference plug for the see-through engine test; a regular side electrode design spark plug | 45 minutes 16 seconds (established as the time to beat for the rest of the no-load test) | about 35 minutes 35 seconds total; transcript states 30 minutes of that was under load and 5 minutes 35 seconds was not under load (this breakdown is garbled and kept verbatim rather than reconciled) | not tested |
| 5Autolite Racing | provided a pretty quick and complete combustion; flame kernel growth patterns varied a little more than some of the other brands; very difficult to distinguish any difference in flame kernel growth versus the NGK, though the Autolite seemed to deliver a little more immediate combustion | 44 minutes 7 seconds, about a minute less than the regular NGK spark plug | did not last quite as long as the NGK's 35 minutes 35 seconds; no exact time given in the transcript | not tested |
How it was tested
- visual combustion and flame kernel growth comparison using a see-through cylinder head engine and high-speed camera
- fuel efficiency test, no load: engine runtime on a fixed volume of fuel in a fuel-injected generator
- fuel efficiency test, under load: engine runtime on a fixed volume of fuel with halogen lights as a load
- go-kart race using the top-performing spark plug against a farm vehicle, for fun/demonstration rather than a controlled brand comparison
“the Polestar seem to do the best we're going to put it in the go-kart and see how it performs”