Which Spark Plugs Brand Wins?
In our test 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 quick take
The short version of why each pick lands where it does, built straight from the measured results.
“the Polestar seem to do the best we're going to put it in the go-kart and see how it performs”
The measured results
Every number below is read straight from the test. Products are listed in the order they finished.
Fuel efficiency, no load (runtime on fixed fuel)
- 1Pulstara little over46 minutes
(grouped with the E3 in this recap statement); some bluing observed on the metal tip of the spark plug afterward
- 2E3about46 minutes 31 seconds
(45:16 baseline time to beat plus about an extra 1 minute 15 seconds)
- 3NGK Iridium46 minutes 7 seconds
still not as long as the E3 or the Pulstar
- 4NGK Copper Core45 minutes 16 seconds
(established as the time to beat for the rest of the no-load test)
- 5Autolite Racing44 minutes 7 seconds
about a minute less than the regular NGK spark plug
Fuel efficiency, under load (runtime on fixed fuel)
- 1Pulstar
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)
- 2E3about36 minutes
and a little over 50 seconds (35:35 was the time to beat), described as very impressive
- 3NGK Iridium
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
- 4NGK Copper Coreabout35 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)
- 5Autolite Racing
did not last quite as long as the NGK's 35 minutes 35 seconds; no exact time given in the transcript
Flame/combustion visual test
- 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
- 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
- 4NGK Copper Core
used as the baseline reference plug for the see-through engine test; a regular side electrode design spark plug
- 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
- 3NGK Iridiumnot tested
All measurements (1 more)+
Go-kart race result
- 1Pulstar
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
- 2E3not tested
- 3NGK Iridiumnot tested
- 4NGK Copper Corenot tested
- 5Autolite Racingnot 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”
