DENSO, one of the world’s leading manufacturers of original Spark Plugs and Glow Plugs, is reminding customers about the importance of timely and correct replacement of plugs for trouble-free engine performance as we move towards the winter months.  

Glow plug failure is highest during colder weather and with night time temperatures having dropped already, now is the time to stock up on replacements. 80% of replacement glow plug demand occurs between September and March and although there are several different types of glow plug on the market, to ensure optimum ignition performance after replacement, it is vital to know which technologies perform particularly well in colder weather. 

DENSO Aftermarket Product Manager, Nick Thomas says, “In winter there are two types of glow plug that can be particularly recommended for diesel cars: Ceramic and Instant Heating.  These technologies provide an extremely reliable, rapid cold start.” He adds, “Instant heating glow plugs in particular are likely to become more prevalent in the future, both as original equipment and in the aftermarket. DENSO’s Instant Heating Glow Plugs even offer a unique advantage, with a heat-up time of around two seconds they achieve the fastest start of any glow plugs in the world.”

When it comes to petrol vehicles, spark plugs are vital to the longevity and clean running of an engine, so the importance of correct torque and gapping techniques cannot be underestimated. Nick explains, “When installers report that plugs aren’t performing correctly, the plug itself is usually not at fault.  Incorrect gapping and torque measurements can sometimes be the cause.” He adds, “Spark plugs replacement is now so easy that sometimes the right tightening checks are overlooked, but they are vital in ensuring that the plug stays intact, and fits and performs correctly.  Over-tightening is the most common problem, which can cause damage to the engine, and/or result in the plug coming off at the thread.”

Correct gapping of replacement spark plugs is vital. Nick comments, “The size of the gap between the plug’s centre and ground electrodes influences the voltage needed to ignite the air/fuel mixture  and the temperature of the spark plug tip. The right gap size will ignite the air/fuel mixture efficiently, producing efficient electrical performance for up to 100,000 miles of driving.  But inaccurate gapping can make a car run roughly, start poorly and have higher petrol consumption.  For both practical and cost reasons, no plug supplier can offer 100% pre-gapped ranges which is why checking the correct gap on fitting is so essential.”

Denso offers a complete range of glow plugs and spark plug delivering OE performance for the aftermarket. The glow plug range features, Double Coil, Extended Post-Heating, Ceramic and Instant Heating plugs and cover 89.5% of the car parc, comprising 132 part references covering 6,096 applications.

The Denso spark plugs range is an all makes, OEM quality programme, advanced technology upgrade programme which includes 685 automotive part numbers covering 40,886 automotive applications which is some 97% of the European car market. There are also almost 400 part numbers covering motorcycle, marine and small engine applications.