20W-50 engine oil – what’s the craic and why might you need it?

If you’ve been poking about trying to find the right oil for your motor, you’ve probably come across 20W-50 a fair few times. But what exactly is it, who’s it for, and why should you bother? Stick the kettle on, grab a biscuit and let’s have a proper natter about this type of engine oil – you might be surprised just how handy it can be.

Who actually needs 20W-50 engine oil?

20W-50 isn’t your bog-standard oil for every car on the road these days, but there are plenty of motors out there that thrive on the stuff. If you drive a classic – think MGBs, old Land Rovers, or any of those real British icons – this is pretty much the gold standard. Those older engines were built for thicker oils, and 20W-50 helps keep them sweet, especially with a few decades under their belts.

It’s spot on for:

✅ Classics and vintage cars – best mate for old-school British classics and some continental favourites too.

✅ Motorbikes and sportsters – popular with bikes, especially big tourers and anything air-cooled.

✅ Old workhorses – vans and lorries that have seen a few winters, or if you haul heavy loads for a living.

✅ Hotter temps and tougher jobs – if your car’s regularly working up a sweat, towing or crawling through traffic on a heatwave day, this oil doesn’t bat an eyelid.

It’s not the right call for modern motors, though. Most newer cars need thinner oils to keep all those high-tech bits and bobs running smoothly. Always double-check your handbook if you’re not sure – better to be safe than sorry!

What makes 20W-50 tick?

There’s a fair bit of science involved, but keep with me. The “20W” bit means it works well on a chilly morning – so it’ll flow around the engine quickly even when it’s cold outside. The “50” bit is all about how thick it stays when things get piping hot inside your engine. Basically, it’s sturdy enough not to turn watery after a long run up the motorway or when you’re stuck in summer traffic.

Most 20W-50 oils are mineral-based (think old-school, natural stuff), but you can get semi-synthetic blends if you want something with a bit more staying power. They’re kitted out with detergents and additives too – things like anti-wear agents (especially helpful for older cams and tappets which can be a bit rattly) and cleaning agents, all aimed at keeping your engine ticking over nicely.

Why bother with it? Here’s the lowdown…

Alright, so what’s in it for you? Quite a lot, actually:

➡️ The thicker oil cushions all those moving parts, so if you’ve got a bit of tappet noise or grumbling bearings, you’ll probably notice things get a good bit quieter.

➡️ If your pride and joy is a bit of a leaker (as most old cars are), the thicker oil helps seal things up a bit and stops you going through bottles of oil every month.

➡️ Perfect if you’re giving your engine a hard time – lots of start-stopping, heavy loads, or taking it on a proper road trip.

➡️ On those rare scorchers, or if your engine tends to run hot, 20W-50 doesn’t thin out and give up the ghost.

Ready to give it a go?

We’ve pulled together a cracking range of top-notch 20W-50 oils – whether you’re keeping a classic on the road, fettling a work van, or want to keep the family bike running like a dream. All the brands you trust, all the technical bumf you’ll ever need, and if you’re unsure what’s best for your pride and joy, just drop us a line – we’re always happy to lend an ear.

Have a mooch about, order online for fast UK delivery, and let’s keep those engines running smooth for years to come.