
The N55 engine was a widely used 3.0-liter turbocharged inline-six found in numerous models from the 2011 to 2018 model years. It was the successor to the famed N54 and was designed to be more reliable and efficient while still delivering strong performance. Key cars equipped with the N55 include the 135i, 335i, 535i, and the X3 xDrive35i, among others. This engine is known for its smooth power delivery and tuning potential, making it popular among enthusiasts.
The N55 is a single-turbo engine (featuring a twin-scroll turbocharger) that incorporates Valvetronic variable valve lift, differentiating it from the twin-turbo N54. While it produces slightly less power in stock form compared to its predecessor, it's generally considered to have fewer common issues, particularly related to the high-pressure fuel pump and injectors.
This engine was the primary 3.0L turbocharged six-cylinder across BMW's lineup for nearly a decade. Below is a list of significant models that used the N55 engine.
| BMW Model | Model Years (Approx.) | Horsepower (HP) | Torque (lb-ft) | Key Notes |
|---|---|---|---|---|
| 1 Series (E82/E88) 135i | 2011-2013 | 300 | 300 | Coupe and convertible versions. |
| 3 Series (F30) 335i | 2012-2015 | 300 | 300 | Sedan and Sports Wagon. |
| 4 Series (F32/F33) 435i | 2014-2016 | 300 | 300 | Coupe and convertible. |
| 5 Series (F10) 535i | 2011-2016 | 300 | 300 | Sedan and Gran Turismo. |
| X1 (E84) xDrive35i | 2013-2015 | 300 | 300 | High-performance SAV. |
| X3 (F25) xDrive35i | 2011-2017 | 300 | 300 | Sports Activity Vehicle. |
| X4 (F26) xDrive35i | 2015-2017 | 300 | 300 | Coupe-like SAV. |
| X5 (F15) xDrive35i | 2014-2018 | 300 | 300 | Larger SUV. |
| X6 (F16) xDrive35i | 2014-2018 | 300 | 300 | SAC (Sports Activity Coupe). |
| 2 Series (F22/F23) M235i | 2014-2016 | 320 | 330 | An "M Performance" version with a power bump. |
If you're looking at a used BMW from this era with a "35i" badge, there's a very high chance it has the N55. It's a fantastic engine, but like any modern BMW powerplant, its long-term reliability is heavily dependent on a rigorous maintenance schedule, particularly for the oil filter housing gasket and valve cover gasket, which are common failure points.

As a former tech, I saw a ton of these. The N55 is in almost every BMW with a "35i" badge from about 2011 to 2018. Think 335i, 535i, even the X5 and X3 SUVs. It's a solid engine, smoother and more forgiving than the older N54. Just budget for those common oil leaks from the valve cover and oil filter housing. It's not a matter of if, but when.

I own a 2014 435i, and it's got the N55. It's the perfect daily driver engine. Plenty of power right from a low RPM, and it sounds great with a nice exhaust. It's the heart of the car—smooth, responsive, and surprisingly good on gas for the performance it offers. If you're one used, a solid service history is more important than low miles.

When I was shopping for my used 335i, I learned to look specifically for the N55. It was in the 2011 to 2015 F30 3 Series models. It's a smarter buy than the earlier N54 engine for most people because it's more reliable out of the box. The key is to find one with all its records. Check for receipts for the common gasket replacements; it shows the previous owner cared.

From a pure performance standpoint, the N55 is a tuner's dream. It's the base for the engine in the M2! You'll find it in the 1 Series, 2 Series (M235i), 3 Series, and more. While it uses a single twin-scroll turbo, it responds incredibly well to simple modifications like a tune and downpipe, easily pushing over 400 horsepower. It’s a modern classic that bridges the gap between raw performance and daily usability.


