In place of a foreword

It's far from certain that every visitor will read all the material on this site, and even less certain that everyone will make an oil choice exactly the way it's laid out here. Still, I'll go out on a limb and say that I consider the reasoning scheme for choosing car oil laid out here to be the only correct one for keeping an engine in good shape for a long time.

Unfortunately, many engine oil makers have gotten too caught up in marketing and don't even bother with guidance on how to correctly pick an oil from their own range.

If you analyse how information is presented in advertising and on the official sites of engine oil makers, you can only conclude that practically all of them abandoned the medical principle of "do no harm" long ago and moved far away from it, since the victims of their advertising are given no information whatsoever about the consequences of picking the wrong engine oil.

Maybe you'll say I'm overstating the importance of choosing the right oil and laying it on thick? Could be, but unfortunately, practice shows that the overall quality and reliability of the engines in new cars of every make has been declining lately, and so new engines are becoming ever more sensitive to the quality and correctness of their servicing. The days of building "unkillable" cars are long gone.