With the widespread use of computerized engine controls, the regular “tune-up” is now a thing of the past. Modern vehicles don’t have ignition points and there are no carburetors to adjust. But there is still an important wear item that needs to be replaced periodically – the spark plug.
Replacing worn or fouled spark plugs can improve engine starts, lower emissions, and even boost acceleration. What’s more, according to the National Institute for Automotive Service Excellence, a misfiring spark plug can reduce fuel efficiency by as much as 30 per cent.
Spark plugs take the electrical current from the ignition coil and send it across a gap between the plug’s electrodes. That spark ignites the air/fuel mixture, which powers the engine. Keep in mind that all this happens in a very harsh environment. Up to 40,000 volts cross this gap, and combustion temperatures can reach 3,000 C.
Even with the greater durability of platinum- or iridium-tipped electrodes, these components eventually wear out.
They also can become fouled due to poor gasoline quality, or excessive oil entering the combustion chamber from worn engine parts. Fouling can even be caused by prolonged engine idling that prevents the spark plugs from reaching their proper operating temperatures.
Be sure to replace your vehicle’s spark plugs on a regular basis. It’s one of the most economical ways to maintain an efficient engine and avoid wasting fuel.