How to choose the right spark plug for your car?

Hi there! I’m Liam Brooks, automotive expert, author of and I’m writing today about the most popular and most frequently bought automotive product, given their popularity — spark plugs. 

As a result, when buying quality spark plugs, people often get a fake well disguised as the original. What is most annoying, not always buying original spark plugs, you “hit the bull’s eye”, the fact is that the spark plugs must be bought taking into account the properties and characteristics of the engine. In addition, spark plugs come in different sizes, materials, differ in heat number, principle of action and, naturally, in their cost.

To help you at least a little in choosing, I conducted my own “investigation” and found out a lot of interesting and most importantly important things that must be considered when choosing and buying car spark plugs. I’ve tested them on 2.7L Turbo engine V8 GMC Sierra

The spark plugs are intended for the combustion of fuel mixture in the cylinders of the internal combustion engine (DBC). Their great diversity in the field of integrating leads to the substitution of even experienced vehicles. Yes, and some “general profile mechanics” are constantly fiddling about and asking questions about motors, electricity and power supply specialists.

Spark plugs should be selected according to the whole number of parameters, depending on:

– from the type of ignition (ontatnoe or freeontatnoe, battery, electronic, etc.);

– from the type of power supply system (atomizer, injector, mono- or multi-point spray, and so on),;

– from the degree of engine speed (degree of compression, and, accordingly, pressure)

– from the operating conditions of the engine and the types of fuels used (deformed, foamed, supercharged, turbocharged, sporty, etc.).

The device and principle of operation of the spark plug

Criteria for selecting Spark Plugs

There are many parameters, however, there are only two most important parameters that cannot be ignored – these are the glow number and the size of the spark plug.

At the expense of the size, I think it is not worth explaining here, everything is extremely simple – a small spark plug will fall into a spark plug well, a large one simply will not fit. It’s like a thing in a store – either small or “just”.

As for the glow ignition, everything is much more complicated. This indicator determines the temperature range of the plug at which the fuel-air mixture will ignite from a spark, and not from a glowing spark plug. A high glow number at the spark plug indicates that the plug is “cold”; it is intended for use on engines that reach high temperatures and are subject to severe stress. A low glow number indicates the opposite – a “hot” spark plug. Hot spark plugs are capable of self-cleaning, so it’s not right to write them down as “unsuitable” ones right away!

The most correct way to select spark plugs is by contacting your dealer or looking in your vehicle’s manual.

But on I’ve prepared a dozen of manuals, e.g.: best spark plugs for GMC Sierra, Yukon, Hyundai Elantra, Ford Focus and many more.