INSTANT EXPERT
In today’s cost-conscious times, supplementary additives promise means of cutting motoring costs but Rob Marshall studies whether you should dismiss them, or not.
Since the motorcar was invented, aftermarket companies have offered all sorts of potions, pledging to increase reliability and/or reduce running costs. Some of them delivered on their promises; others fell notably short. Yet, it would be unfair to judge additives used by our forebears as totally useless. Some of them were necessary, so much so that separate dispensers at petrol forecourts used to be popular. These upper cylinder lubricants reached the areas that oil alone could not and helped discourage carbon build. Refinements in engine design particularly rendered such additives redundant – or have they? The fact that additives have not just disappeared but have become more prolific indicates that their relevance has grown, rather than diminished.
While modern power units are more fuel efficient, more powerful and cleaner than their ancestors, these advantages come at a cost. Reduced internal tolerances make them less tolerant to contaminations, which build as the vehicle ages. Furthermore, cars have become considerably more complicated, particularly with the proliferation of exhaust emission after-treatment systems. For these reasons, inhibiting and removing contamination build is the main aim of automotive additives.
One would expect manufacturers to endorse additives openly; but they do not. An explanation may be purely brand protection. As regular readers appreciate, taking carmakers’ advice is not always in our best interests, especially where maintenance intervals are concerned. Experienced DIYers are, quite justifiably, suspicious of the official recommended engine oil change rates that tend to be too long, especially for sealed-for-life lubricants that are used in transmissions. Of course, CM readers’ definitions of what constitutes ‘life’ is likely to be more ambitious than that of car manufacturers, one of which revealed to us that it was seven years – afigure that is well below the current average car age in the UK. Of course, additive manufacturers are vying for your hard-earned cash, which would make some readers suspicious of them. We should also consider that additives do not have to fulfil any formal technical specifications – unlike manufacturer-approved lubricants, for instance. While this fact might explain car manufacturers’ caution, it also means that you should buy with care.
