Oil extraction pump: €25 versus the workshop

Change your car's oil for €25 without setting foot in a workshop

A 12-volt suction pump, connected to the battery with two clips, extracts the used oil through the dipstick tube. It costs between €25 and €30 and, according to the calculations circulating among those who already use one, pays for itself after just a few oil changes. The method avoids the pit, the jack and the sump plug. In return, it leaves behind a residue that its defenders consider not only harmless, but beneficial.

The idea behind the gadget is simple: you insert the tube where the oil level is measured, pump, and the oil comes out from the top. No staining the floor, no loosening anything underneath. The residue that remains —a small sludge with metallic microparticles and additives— is not a flaw according to this school of thought: those particles, it argues, fill the clearances that develop in the moving parts of any engine with mileage on it. Hence its second warning, the one that causes the biggest stir.

Why you shouldn't put a cleaning additive in an old engine

Because it flushes out exactly that. The argument is that an engine above 100,000 kilometres has adjusted its clearances around those residues and that an aggressive cleaner removes them all at once. The result, they say, is an engine that runs terribly. It is not a thesis with laboratory backing in the material available, but it explains why part of the saving lies not in the oil but in what you decide not to do to it.

On the oil itself, the position is just as heterodox: the base oil is the same in every brand and what changes is the additive package. That is why supermarket own brands come out looking good against premium labels. The discussion splits, however, over the change interval.

Change the oil every 25,000 kilometres or once a year

A driver with a five-year-old car and 118,000 kilometres on the clock admits to four oil changes and only one filter change. His thesis: frequent changes are a rip-off and the filter barely matters. Opposing him is the recommendation not to go beyond a year even if the mileage hasn't been reached, because oil loses its properties over the winter. And a third voice, the one with the most technical consensus: change the filter at every oil change, which costs six euros.

That's where the harmony breaks down. A suction pump doesn't change the filter, and the filter is half the maintenance. Those who defend the traditional method —loosening the plug with the car level and letting it drain— argue that suction doesn't pull up the grime at the bottom and that the magnetic plug never gets cleaned. The contrast is amusing: comparing a barbecued meal with a hamburger, they say.

Where to dispose of used oil and what happens if you get caught

The weak point of the saving. Used oil is hazardous waste and not just any spot will do. The legal route is the recycling centre, which collects it for free, and it also accepts frying oil. Pouring it into a roadside ditch is another matter: besides being disgusting, it's an offence. The temptation of the public pit —they exist, though they're hard to find— solves the draining but not the final destination of the liquid.

The initial outlay varies. There are pumps for 16 euros, others between €25 and €30, and they turn up in large DIY and car parts stores. For someone doing one change a year, it pays off slowly. For someone servicing several cars, the maths changes. And for anyone without a pit or a ramp, it's the only way to avoid paying at the till.

The question nobody settles remains: does the residue protect or wear? With the filter at six euros and the oil at own-brand prices, the decision is less technical than it seems.