do expensive/premium spark plugs make a difference?

londonTiger

I generally buy trusted brands like bosch and ngk. But even within brands you can get plugs at £2.50 each or you can get iridium/platinum plugs that are £10 each.

I'm curious. Does it make a big difference in efficiency or are they all more or less the same for normal use.

The car is a 1.6L and is a low powered ordinary passenger car. So not used for racing or anything crazy.

Babbawah

It's called an idiot tax.

Herzlos

It may make a difference on something high end that's tuned to within an inch of it's life, but I doubt it'd make any difference to any normal car.

Strider590

It's worth buying a good brand, but it's not worth paying extra for the gold plated super mega quadraspaz plugs.

I personally rate NGK, the set in my kitcar really have to stand up to some non-standard conditions (high temp and high compression) and they do so very well.

atrixblue.-MFR-.

Its not a money making exersize at all.


iridium plugs are made for the focus RS applications, as they can stand the heat of performance engines cylinders putting normal copper core in it would just melt the tips and send that metal round the engine causing damage.


same in the 1.8 and 2.0 zetec (non RS) titanium tipped plugs are fitted to the zetec due to combustion chamber heat and longer efficiency.


If you reverse it in a non application for the plugs, it can have adverse affects such as valve seat wear or burnt valves. such as fitting twin spark tipped plugs to a 1.3 fiesta instead of copper cores.


manufacturers usually recommend two types of plugs for different types of conditions INC weather conditions the engine maybe put under, for e.g a higher rated plug for minus 10oc countries to counter the extreme cold air intake and fuel mixtures.


so its not just a money making gimmick theres a reason why some applications have 2 sets of plugs, such as copper core and titanium.

s_b

buy plugs recommended by manufacturer or what your trusted indy recommends by knowledge,i will only fit ngk in most motors as an indi

Flying-High_2

For every pound extra they cost they produce 2bhp.... I had £100 Chinese ShangRacingF1double+ plugs in my V8 S4 Avant... True story

Joe_Horner

The main (in practice, only) benefit of them is extended life. As manufacturers push service intervals to silly extremes in the interest of marketing, plug change intervals have reached 30 or 40K miles (probably more by now!)

Good quality standard plugs won't last that long, but they'll work just as efficiently for their (shorter) life of typically 15 - 20k (with cleaning / gapping at each service).

Standard plugs have been used in engines running far higher power, revs and compression levels than poxy little Ford RS models - like this for example:

http://www.historicengines.com/dfv/specs.html

450+ BHP, 10.5k revs and 11:1 compression on 101 octane fuel, with standard nickel (not even copper cored!) G56R plugs without "melting the tips and sending metal particles round the engine".

But they had to change them fairly often

For road use, and apart from the ability to practically never be changed, they're nothing more than a nice marketing gimmick

londonTiger

thanks for the answers. i'll stick to standard ones I dont mind pulling them out every 2 years or so - at least it will get me into the habit of peering into the cylinders occasionally and checking if everything is running smooth

forgotmyname

If your cylinders are smooth you need a new engine.

marlot

Joe_Horner wrote: »

The main (in practice, only) benefit of them is extended life. As manufacturers push service intervals to silly extremes in the interest of marketing, plug change intervals have reached 30 or 40K miles (probably more by now!)...

62,500 for my car (Mazda MX-5 with a Zetec engine)