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!
