ne, you’ve probably seen codes like B58, N57, or S63 thrown around online. They show up in listings. In forums. On spec sheets. And they matter.
These aren’t just random numbers. They’re your shortcut to understanding what’s really under the bonnet, the most important part, engine.
Because when you know how to read them, you know what you’re getting.
Performance. Reliability. Tuning potential. Or maybe all three.
Here’s everything you need to know about BMW engine codes, especially the ones that matter in 2025.
Why BMW Engine Codes Actually Matter
BMW doesn’t label engines at random. Each code tells a story.
What year the engine was designed. How many cylinders it has. What kind of fuel it runs on. And whether it’s made for daily drives, or made for M cars.
When you’re looking for used engines or comparing different models, these codes can help you avoid the wrong buy. They can also point you toward the engines that are worth building on.
The B-Series: BMW’s New Era of Engines
In 2015, BMW introduced the B-series, a new generation of modular engines.
They were designed for one thing: flexibility.
Petrol or diesel. FWD or RWD.
The architecture was the same.
That meant fewer moving parts. More efficiency. Easier tuning. And lower emissions across the board.
B48 Engine – A Solid All-Rounder
You’ll find the BMW B48 engine in the 1 Series, 3 Series, X1, and even the MINI Cooper S.
It’s a 2.0L turbocharged inline-four with between 135 and 265 horsepower.
Not built to set records. But it’s light. Responsive. Efficient. A great engine for everyday driving with just enough punch when you need it.
It replaced the older N20 and did everything better.
B58 Engine – The Sweet Spot for Enthusiasts
If you’ve driven a 340i, Z4 M40i, or Toyota Supra, you’ve felt the BMW B58 Engine.
It’s a 3.0L turbocharged inline-six.
Power ranges from 322 to 382 horsepower, but that’s just the start.
The B58 engine delivers smooth, linear power with real tuning potential.
It’s based on the B48, but stretched out and beefed up.
It replaced the BMW N55 engine and quickly earned a reputation as one of BMW’s best modern engines.
BMW S58 Engine – M Division’s Take on the B58
Found in the G80 M3, G82 M4, and X3 M, the BMW S58 engine is built for performance.
It’s based on the B58 engine, but every part is stronger, faster, and sharper.
Twin turbos. Forged internals. Track-ready cooling.
It produces between 473 and 503 horsepower and it doesn’t stop pulling.
This is what happens when the engineers at BMW M are let loose on a six-cylinder.
The N-Series: Still Strong, Still Relevant
Before the B-series came the N-series.
These engines powered everything from the E90 3 Series to the early X5s and 7 Series.
Even now, many of them are still on the road.
Still pulling. Still reliable.
N57 Engine – The Diesel That Made Diesel Fun
The N57 is a 3.0L turbocharged inline-six diesel. You’ll find it in cars like the 330d, 530d, and 740d.
Power ranges from 215 to 375 horsepower. But it’s not about top-end speed. It’s about torque. Mid-range pull. Long-distance comfort. And surprising efficiency.
Still one of the best diesels BMW ever made.
N63 Engine – A Twin-Turbo V8 with a Lot to Prove
The BMW N63 Engine is a 4.4L twin-turbocharged V8. Used in the 550i, M550i, and X5 xDrive50i. It puts out between 445 and 523 horsepower.
Early versions had their issues. But later revisions fixed the weak spots. Now, it’s a powerhouse, smooth, fast, and refined.
Perfect for those who want big power in a luxury package.
The S-Series: Built for M Cars, Built to Win
BMW’s S-series engines aren’t for daily cruising. They’re built by BMW M for one thing: performance.
BMW S63 Engine – The Flagship V8
This is the one you’ll find in the M5, M8, X5 M, and more. It’s a 4.4L twin-turbo V8. Power? Anywhere from 567 to 617 horsepower.
It’s based on the N63, but with race-ready parts. Better turbos. Better pistons. Better cooling. And when you step on it, it moves fast. It’s aggressive. Loud. Unapologetically fast.
And if you’ve ever wondered what peak BMW performance looks like, this is it.
Quick Recap: What These Codes Mean in Plain English
The B48 is small, efficient, and great for everyday use.
The B58 is the modern sweet spot, smooth, powerful, and highly tunable.
The S58 builds on that with M-level performance for serious driving.
The N57 is still a top-tier diesel, especially for long distances.
The N63 is a strong V8 for luxury performance.
And the S63? It’s the most powerful engine BMW currently makes.
Which BMW Engine Should You Go For?
It depends on what you drive—and how you want to drive it.
If you’re after smooth daily power with room to grow, go for the BMW B58 engine.
If you’re chasing torque and efficiency, go for the N57 engine.
And if you want nothing but raw, unfiltered power, there’s only one answer: S63 BMW engine.
MT Auto Parts, one of the best BMW breakers, stock all of them and can help if you are looking for a BMW engine for sale with more affordable prices. From clean B48s to fully tested S63 powerplants.
Every engine is inspected, compatibility-checked, and shipped anywhere in the UK.
So if you’re ready to upgrade or replace your BMW engine, you know where to for — mtautoparts.com
