Do Spark Plugs Matter? CHEAP vs EXPENSIVE | Engine Masters | MotorTrend

Can any one type of spark plug make more power than the next? What if you gap them bigger or smaller? Let's find out on Engine Masters!

#MotorTrend #enginemasters #sparkplugs

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[MotorTrendWatch]

Did any of these test results surprise you?

[HITTHEHAZARD]

Testing and comparing different parts on this channel are my favorite episodes 🙌

[theelifeofdez]

So get regular plugs and open the gap a tiny bit.

[BuzzinVideography]

O'reilly's manager here... I NEVER have NGK or ACDelco brought back with problems.
Other, cheap brands, have had issues. Last week a guy brought back a set of autolight APP65 that lasted 5, 000 miles and the electrodes were GONE. Ground straps ghosted. All of them.
He replaced ACdelco plugs after 90, 000 miles.

[raiderjohnthemadbomber]

I run a 1974 Nova with original Gen I 350. I installed O2 sensors on a dual exhaust header combination. This allows me to monitor performance and fuel economy and know whether the problem is isolated (plugs, etc.) or general like carb, distributor, etc. Using a carb I also run a vacuum gauge. This system has served me well. I do open plug gaps routinely and get enhanced performance in every situation.

[PhattyMo]

I've always had the best luck with regular NGK plugs. Smoother running, fewer misfires..overall better. They just work like a spark plug should..I've tried quite a few other plugs, and always go back.

[joshghazi]

im so glad engine masters is back on youtube, its been years since ive watched one, also, missing the coolest sparkplug which is a pulseplug with built in capacitor, also plugs wont really shine unless you and increase the pressure inside the cylinder until it cant jump the gap. also other factors to consider is the sparkplugs ability to light up ultrarich or ultra lean mixes, some plugs will perform better than others depending on its design and how it creates hot spots in the cylinder

[scotteddy]

Old vid but I've run NGK for everything since I was young. They've never failed. Playing with spark gap is nothing new. Cool to see it tested again. E3 has unmatched mpg gaines. Keep up the awesome work💪

[bradfordeaton]

Chris Jacobs in his book on ignition systems points out that the main concern is the flame kernel. A wider gap requires more wattage to jump and produces a bigger and hotter flame kernel. The multi electrode plugs just mask the kernel from various directions. He goes into much greater depth than this but for the purpose of this post, it's pertinent. The simple Autolite plug with the wider gap produced the most power. And cheap(ish)!

[jbcowherder]

so i can attest to the longevity of Irridium/platinum plugs in an engine WITH a ignition system designed to use them: as a retired ex-Toyota technician for the last 25+ years i can say multiple times we had customers bring in vehicles with over 200k on the original irridium/platinum plugs that were installed at the factory- still running strong.
what really matters is proper design, and using the proper plug for the engines ignition system is key.

[MikkellTheImmortal]

It doesn't happen often, but I learned literally nothing from this episode. I'm actually quite surprised at that.
So in the interest of education, I will provide a little.
The reasoning behind the multiple grounding straps is to give the arc a greater chance of developing, reducing the possibility of misfire.
Tip for your old copper plugs when you open the gap, you can leave your gap coin in between the strap and plug and using pliers you can push the strap back over to the center while maintaining the gap (only works with gap coins).

[CarsandCats]

I've always ran the Autolites and change them often. A cheap fresh plug is much better then an old expensive one!

[rainsfrd]

great episode boys! While a larger gap will net you a bit of power on a NA setup, the same cannot be said once you go boosted. Why? Spark kernel strength! Keeping a larger gap can, effectively 'blow the spark out' as you add boost.

For example, you might have shrink your plugs from 32 thou down to 28 or 24 thou once you've increased boost. I think the rough rule was 4 thou for every 50 HP, and swapping to a colder range plug also helped.

Would love to see you guys explore spark plug gap on a boosted setup as well!

Cheers,

- rains

[dastardlyman]

in one of david vizard RECENT books he says a small amount of plug resistance is best ie 200ohms they often come with thousands of ohms. lets be even more clear he measured the resistance in the plugs and leads combined. ignition is VERY important if you have a chamber that is hard to light up.

[randr]

I actually noticed this gap thing with plugs on an old Saturn that I had. I was trying to eek out a bit more power from that little 4-banger, but things that make power often translate to MPG and I consistently got better mileage with that car when I ran bigger plug gap. My setup was Accel coil packs and NGK plugs with I think 0.055" gap (it's been over a decade so forgive my poor memory but I do know it was significantly more than the OEM spec of 0.040"). I tried this with the factory coils and it would not run right with those so I know the higher voltage coils made a difference. On a highway trip shortly after I did the mods this car got 42 mpg, which is pretty good considering that those cars are EPA rated for 32. I don't know if power changed at all but it did feel faster. I read from some people who know more than me about those cars that the tune was a bit rich from the factory, so maybe the extra gap was helping get more complete combustion on that rich AFR. I don't know exactly why but the results were way better than I expected, especially the mpg. I did some other mods to that car, which was quicker than you'd think due to its lightness, but that plug gap/coil upgrade thing was a big surprise for me. It yielded the best results.

[CarsandCats]

Forgot to add that you CAN make more power with side gapped Autolite Racing plugs, but they don't last long on the street as the gap opens as they wear because it eats the edge of the electrode off.

[forterierocks]

Have you ever done an episode on air filters? Like is it worth the money for a K&N over an OEM replacement or whatever the parts store has🤔

[jameseroh]

I found that using Autolite Platinum and Double Platinum spark plugs gave the best power and fuel economy at part throttle operation. When I used the Autolite plugs in 7k watt Honda generators that were running air conditioners at a remote site 24/7. The tank of fuel would last 8.5hrs, up from 6hrs with the standard plug. Running Mobil 1 oil instead of conventional multigrade oil, added another hour to the run time.
On the dyno, what were the differences with the BSFC?

[davidvaughn]

My take is this:

1. If youre racing/ like to tinker with things go copper. They are cheap if they foul etc. When/if they foul up or otherwise wear out you have an excuse to tinker again.

2. If youre putting plugs in your daily driver grocery getter, go ahead and spring for the platinum or iridium plugs. They really do last a long time. If i remember correctly, platinums have a 100k mile life expectancy.

[Harleyforever]

That was a interesting episode. What I really want to know is what the gains are when you go up or down a heat range AND appropriate tuning adjustments are made. For example, timing and fuel.