rev up your engines, today I'm going to talk about the best spark plugs for your
car's engine and why they are the best ones, now over the past hundred something
years spark plugs do one basic thing in a gasoline engine, they fire the air and
fuel mixture so there's an explosion that pushed the pistons down, now the
early spark plugs hey they didn't fire all that great, the really early ones
you could actually take them apart into different pieces, clean them and fix them, put
them back together and use them over, and after that for decades and decades most
spark plugs had copper electrodes in them, copper is a good of conductor of
electricity so they would conduct the electricity that would make the spark that would
fire the gasoline air mixture, but if you know anything about copper hey it may
conduct electricity quite well but it's extremely soft, so what happens is it
would wear out in a reasonably short period of time, back in a day when I was
a young mechanic, hey you'd be lucky if you got twenty thousand miles out of a
set of spark plugs, sometimes we had to change them even closer if it was an
engine that was worn and burned some oil, so they didn't last all that long, then
they went to platinum spark plug, because platinum hey it's much harder, it keeps
its sharper edge long and where the spark plugs fire you want a sharp edge
for the spark to fire correctly, Platinum spark plugs can easily last a
hundred thousand miles and another advantage of the Platinum spark plugs is
they generally run a little bit hotter than the copper plugs do, it's running
hotter they burn the deposits that get on your spark plug off better so the
spark plugs can last a lot longer, even if your sparks firing right if it gets
clogged up with unburned carbon parts it won't fire right, but then came Iridium
spark plugs the top-line ones now, iridium is six times harder than
platinum, so it lasts even longer, plus it has a 700 degree hotter melting point
than the Platinum does, so they can last an awful long time these Iridium spark
plugs, I personally have seen some Chevy v8 engines
that had two hundred thousand miles on them and the Iridium plugs had never
been changed and it still ran fine, now of course the iridium once cost more but hey the
price keeps coming down, now you can easily get them for seven or eight
dollars a piece and there's a big reason that many engines now use iridium plugs
from the factory, and that's because they're making spark plugs harder and
harder to get to, as an example this Lexus behind me is a v6, the front three
cylinders are real easy to get to, they're out in the open the front three
simple to get to, but the back three are under the intake manifold and you have
to take the intake manifold plenum completely off to get to those three
smart plugs, it is a gigantic job, and there's many modern engine designs that
are even worse than that, some of them you practically have to pull the
engine out of the car to change all the spark plugs, so iridium makes sense if
you can get two hundred thousand miles out of a set of spark plugs hey most
people are gonna be happy with that, now the copper then the platinum then
the Iridium, those are the three main plugs that go into cars, but there are a
bunch of these wild and crazy manufacturers that design plugs that have
four electrodes or are made all even different materials and they claim they
boost your horsepower and make you a better gas mileage well, stay away from
that stuff it's just nonsense, now ages and ages ago a spark plug design could
have made a change like in the 60s where you had points and condensers just
mechanically opening and closing and firing the spark plugs through the
distributor, a lot of those systems didn't have all that much power and if
you replace the stock spark plug in those with one that fired better they would
have actually run better, but it spent decades and decades since theirs been points
and condensers, all the systems are electronically controlled now, the stock
spark plug that comes with the car is what's designed for the car and will
generally work best, again in this 94 Celica hey it's got
electronic ignition in it, the stock Nippon Denso was the best plug for it, it
was designed by engineers it's the right fit and speaking of the right fit, let me
tell you a horror story, years ago I had a customer come over here with a 300
Z nissan sports car, and it clacking like mad and I said, well when
did this start and the guy said, well I changed my spark plugs and right after I
changed the sparks it just started making all that noise, so I said okay
let's stop right there, I pulled out one of the spark plugs, I looked at the spark
plug and I could see the top of the spark plug was hitting something it had
metal shiny parts on it where it was wearing, well nothing's supposed to touch
the top of the spark plug in the engine, I went to my auto parts store and got a
set of six spark plugs, and I measured them against the spark plug that I'd
taken out, well it turned out that the spark plugs he installed were like this much
higher instead of fitting flush like this they stuck in the engine this much
higher, and it was actually hitting the top of the Pistons, it turns out he used
a discount auto parts store and the software that they had strangely enough
was typed up in South Korea who knows these days what kind of technology goes
on, and one of those guys made a mistake and they said that these long spark
plugs belonged in his car that had shorter spark plugs, they sold him the
wrong ones, now he was extremely lucky because he did it fast and brought it to
me and I put in the right ones and after about a day of driving the noise went
away, so it didn't really seem to have damaged it in the long run even though
that noise was pretty rattling to his peace of mind when he started it up and
heard it, so really you can't beat the stock spark plugs, always try to get the
same exact spark plug the car came with, and don't trust anybody take one of your
old ones out and when you take it out you can either match the number this has a
big number on it, or at least when they sell it to you match it up to make sure
it's the same size and that's exactly the same length of threads as your old
one, because you don't want one that's too deep that's gonna hit the pistons or
one that's too shallow and it won't fire the flame correctly, engineer spent years
refining engine designs, refining the spark plugs that go in them
your going against all that knowledge if you decide to swap out to a different
spark plug, it has to be the right size and it has to be the correct heat range
for normal driving, but that said there is one exception, you had a car that say
came with a Platinum sparkplug or a copper sparkplug
you could upgrade to an Iridium spark plug if an Iridium spark plug is made
that will fit in there, you're not gonna get more horsepower, you're not gonna get
better gas mileage, but you're gonna get longer life, like in that Lexus it didn't
come with iridium plugs but I put them in, because it was such a pain to take
that manifold off I put in Iridium spark plugs, now I have to admit the platinum
spark plugs and I took out of it had nothing wrong with them, I had to take
off the valve cover gasket on that side because even though it was a Lexus things
wear out eventually and it was 16 years old and this stupid little rubber gasket
on the valve cover was leaking oil, I figured as long as I'm taking that
manifold off so I could change the valve cover gasket I"m going to change the spark
plugs too, if they make an Iridium spark plug that will fit in your engine when
you go to an auto parts store and they look up and you match it with the old
one that's the same size, go right ahead and put an Iridium version of the
original spark plug, but don't think that there's some magic spark plug out there
that's gonna make your car run better by some crazy design that somebody thinks
is going to work inside an engine better than what the engineers designed it for
and since this is mechanic Monday I'm giving away a set of original equipment
spark plugs, to have a chance to win just place a clean non offensive
comment on the youtube comments below and the winner will be chosen randomly
by a computer to get brand spankin new original equipment spark plugs for their
car's engine, so if you never want to miss another one of my new car repair
videos, remember to ring that Bell!