Magnet on Oil Filter – Good Idea?

filtermag oil filter magnet

Old theory to protect engine

Here’s an email from a Behind the Wheel reader that is sure to put the cat among the pigeons…

Hey guys, what do you think of these magnets that you can buy that stick on your oil filter? Do you reckon it’s worth doing?

Thanks, Rob.

Hey Rob, thanks for sending in your question and for reminding us about this concept that has, quite frankly, been around since Henry Ford was in short pants!

There is some solid scientific fact behind this idea – simply, magnets attract metal (I’m sure we all know that).

The theory is that the magnet will attract and hold any metal fragments that might be floating around in your car’s engine, thus protecting it from those little fragments causing any further damage.

Of course, using this same principal, manual transmission oil drain plugs used to be (or still are?) magnetized and this collects the little teeth you rip off your gears in those “don’t grind em, find em” moments.

Is it worth going to the trouble and putting a magnet on your oil filter? Or buying a ready-made one off the internet (for up to $100!!)? Is it a case of “it can’t hurt”?

Well, its unlikely to do any harm, despite what some naysayers believe – they say¬†there’s a chance the magnet can magnetize the metal shards and fragments into a clump that can dislodge and cause real trouble – we reckon this is unlikely.

It is likely that it won’t affect the performance of the oil, or the oil filter, and is extremely unlikely to negatively affect any other of your car’s components.

In saying all that, especially with today’s modern engines, it’s extremely unlikely that the magnet will make any difference whatsoever to the life of the engine in the long run.

By the way, we’ve also heard of people using the same concept but instead placing the magnet(s) in the oil filter, and/or on the engine sump.

Our verdict? Don’t bother!

*Update – Rodney sent us an email reminding us about some of the now classic models that share engine and transmission oil and could be prime candidates for the magnet on the oil filter technique.

These include the classic MINI, as well as models/variants from Austin, BMC and Leyland such as Morris models.

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