Which BMW Has the B38 Engine? Full Model List Explained
Image: BMW B38 engine for sale at mtautoparts.com
BMW owners tend to care about engines more than they first admit. Even people who say they’re “not bothered” usually change their mind the moment reliability, running costs, or a repair bill enter the conversation. Suddenly, what’s under the bonnet matters a great deal.
That’s exactly where the B38 engine sits.
It’s BMW’s 1.5-litre, turbocharged three-cylinder petrol engine, introduced in the early 2010s and used across a wide part of the BMW range ever since. On paper, it was never designed to impress enthusiasts. Power outputs typically range from around 109 hp in the 116i to 136 hp in the 118i, figures that sound modest but are perfectly suited to everyday driving. Over the last decade, this same engine architecture has powered hundreds of thousands of BMWs, quietly doing its job with little fuss and, in most cases, very few serious issues reported.
BMW’s confidence in the design is telling. The brand even used a high-output version of the B38 in the BMW i8, where the petrol engine alone produces over 230 horsepower before the electric motor is added. That single decision says more about the engine’s strength than any brochure ever could.
Still, confusion follows the B38 everywhere.
Which BMWs actually use it?
Why are there so many different engine codes?
And is a three-cylinder BMW engine really a good idea in the long run?
Let’s go through it properly. Slowly. Clearly. Like one BMW owner explaining it to another over a cup of tea.
First Things First: What Is the BMW B38 Engine?
The BMW B38 engine is a 1.5-litre, turbocharged, three-cylinder petrol engine. That’s the simple description.
What matters more is how BMW built it.
BMW didn’t design the B38 as a cheap standalone engine. It’s part of a bigger family:
B38 – three cylinders
B48 – four cylinders
B58 – six cylinders
All three are based on the same core design. Same thinking. Same layout principles. Same approach to cooling, timing and efficiency.
In very plain terms, the B38 is basically a B48 with one cylinder removed. That’s why it feels more refined than people expect from a three-cylinder engine.
This wasn’t about cutting corners. It was about building one engine platform and using it smartly.
Why BMW Uses the B38 So Widely
BMW uses the B38 because it fits a specific role.
It’s compact. It’s light. It’s efficient. And it’s strong enough for everyday use.
That makes it ideal for:
Entry-level BMWs
Family-focused models
Urban and mixed driving
It also makes it cheaper to support long-term. BMW parts availability is good. Knowledge is widespread. And BMW has years of real-world data behind it now.
So… Which BMWs Actually Have the B38 Engine?
This is where most people get stuck. Badges don’t help. Trim names don’t help. Even model years can mislead.
The only thing that really tells the truth is the engine code.
Below is a clear table showing which BMW models use the B38 engine, and which versions you’re most likely to see.
BMW Models Fitted With the B38 Engine
One important thing to understand here:
Two cars can both say 118i on the boot and still have different B38 engines under the bonnet. That’s why relying on badges alone often leads to mistakes.
Let’s Talk About B38 Engine Codes
BMW engine codes look complicated, but they’re not random. Each one tells you how the engine is set up and what it’s meant to do.
Here’s what the main B38 codes actually mean in the real world.
Early B38 Version
B38A15A
This is one of the earlier 1.5-litre B38 engines. You’ll mostly see it in early F-generation (F40, F44), 1 Series cars. It’s simple, relatively low-stress, and doesn’t have as much emissions equipment as later versions.
The Most Common BMW B38 Engines
B38A15M0 and B38A15M1
These are the B38 engines most BMW owners come across.
M0 is the earlier calibration. M1 is the updated version, usually to meet later emissions rules.
From a reliability point of view, both are solid when serviced properly. Differences are mostly software and emissions-related, not mechanical.
Efficiency-Focused Variants
B38A15U0 and B38A15U1
These are tuned for smoothness and fuel economy rather than performance. BMW uses them mainly in the 2 Series Active Tourer and Gran Tourer.
They suit family cars. School runs. Short trips. Everyday use.
Later Technical Revision
B38A15F
This is a later revision of the B38, most commonly found in the F40 generation, 1 Series BMWs. Changes are usually linked to newer electronics, gearbox integration and emissions compliance rather than big mechanical updates.
The BMW i8 Exception
B38K15T0
The BMW i8 uses a B38-based engine, but this one is a different animal.
It’s reinforced. Tuned harder. Designed to work with an electric motor. It shares DNA with the B38, but it’s not interchangeable with standard engines.
Is the BMW B38 Engine Actually Reliable?
Short answer: yes.
Longer answer: yes, when it’s used the way BMW intended.
The B38 has a modern timing chain design. It doesn’t suffer from the old chain issues people still worry about. Internal stresses are relatively low. Cooling is well thought out.
Where problems appear, they usually come from:
Oil changes are being left too long
Cheap oil
Ignored warning lights
That’s not unique to the B38. That applies to almost any modern BMW engine.
For town driving, mixed use and sensible ownership, the B38 has proven itself quietly dependable.
Buying a Used BMW With a B38 Engine: What Matters
If you’re looking at a used BMW with a B38 engine, keep things simple.
Focus on:
The exact engine code
Whether the car is FWD or RWD
Service history
What comes with the engine if it’s being replaced
BMW’s shared-engine strategy actually helps here. Because the B38 appears across several models, availability is good, and prices tend to be reasonable.
This is why specialist BMW breakers like MT Auto Parts always work by engine code first, not guesswork based on badges.
Why the B38 Gets So Much Doubt
The B38 isn’t disliked because it’s bad. It’s disliked because it’s quiet.
It doesn’t sound sporty. It doesn’t chase a lot of power. It just works.
And for many BMW owners, that’s exactly what they want.
Plenty of long-term owners report smooth driving, low running costs and very few surprises. That’s not luck. That’s a well-designed engine doing the job it was built for.
Quick Recap: Which BMW Has the B38 Engine?
BMW 1 Series – 116i, 118i (F20, F21, F40)
BMW 2 Series Active Tourer – 218i (F45)
BMW 2 Series Gran Tourer – 218i (F46)
BMW i8 – high-output hybrid B38 variant
In Conclusion
The BMW B38 engine was never meant to impress enthusiasts on paper. It was meant to make everyday BMW ownership easier, cleaner and more predictable.
Most confusion around it comes from engine codes, not real-world problems. Once you understand the differences between B38A15A, B38A15M1, B38A15F, B38A15U0 and B38K15T0, the picture becomes very clear. Choose the right engine. Match it properly. Look after it.
Do that, and the B38 will do exactly what BMW designed it to do, quietly and reliably.
Frequently Asked Questions
Which BMW models actually use the B38 engine?
In the UK, the B38 mainly are used in BMW’s smaller petrol cars. You’ll find it in the 1 Series (usually the 116i and 118i), in the 2 Series Active Tourer and Gran Tourer (218i), and in a very different, high-powered form in the BMW i8. Which version you get depends on the year and the exact model. That’s why two cars with the same badge can still be very different underneath.
Is the B38 engine the same in every BMW?
Not quite. The core engine is the same, but there are different versions. BMW tweaks software, emissions equipment, and sometimes the way the engine works with the gearbox. To the eye, two B38 engines might look identical. In reality, small details can make a big difference when it comes to parts or replacements.
What do codes like B38A15A, B38A15M0 and B38A15M1 actually mean?
They’re BMW’s internal engine codes. Think of them as revision labels rather than totally different engines. In real life, most mechanics don’t sit there debating the letters and numbers. They check the VIN, confirm what the car needs, and match the engine properly using BMW systems. The code matters, but it’s usually handled behind the scenes.
Is the BMW B38 engine reliable?
For most owners, yes. When it’s serviced properly, the B38 has a good track record. It uses a modern timing chain setup and isn’t pushed especially hard. Problems usually come from skipped services, cheap oil, or warning lights being ignored, not because the engine itself is badly designed.
Is a three-cylinder BMW engine really a good idea?
It depends on how you use the car. For commuting, town driving, and everyday use, the B38 makes a lot of sense. It’s smooth for a three-cylinder, economical, and cheaper to run than bigger engines. If you want something sporty or emotional, this isn’t it. But BMW never meant it to be.
Are B38 engines common in the used parts market?
Yes, they are. BMW used the B38 across several models for years, so availability is generally good. That also helps keep prices sensible compared to rarer engines. It’s one of the quieter benefits of BMW’s shared-engine approach.
Disclaimer: This article is provided as general guidance only. BMW engine specifications can vary by year, market and emissions standard. Always confirm engine codes and compatibility before purchasing BMW auto parts or replacement engines. Delivery and warranty terms apply (T&C apply).
