
X1, BMW 1 Series, BMW X2, and BMW X1 New Energy are equipped with three-cylinder engines. The function of the engine is to convert the thermal energy of gasoline or diesel into mechanical energy by burning the gas in a sealed cylinder to expand the gas and push the piston to do work. Taking the 2021 BMW X1 as an example, it is a compact SUV with body dimensions of 4565mm in length, 1821mm in width, 1620mm in height, a wheelbase of 2780mm, and a fuel tank capacity of 61 liters. The 2021 BMW X1 is equipped with a 1.5T turbocharged engine, with a maximum horsepower of 140PS, a maximum torque of 220Nm, a maximum power of 103kW, and is paired with a 7-speed dual-clutch transmission.

has previously launched several models equipped with three-cylinder engines. For example, the currently available BMW 1 Series hatchback, specifically the 118i variant in the overseas F40 generation, features a 1.5T three-cylinder engine. While not particularly powerful, it is quite fuel-efficient and well-suited for city driving. Additionally, models like the BMW 2 Series Active Tourer and Gran Tourer, which are family-oriented vehicles, also utilize three-cylinder engines. I've test-driven them a few times, and the three-cylinder engine performs adequately in these compact cars, offering agile handling. In the SUV segment, the latest U11-generation BMW X1 still offers an sDrive18i version with a three-cylinder engine, though higher trims have switched to four-cylinder units. The older X2 also used a three-cylinder engine, but it has been largely phased out in the newer models. A notable exception is the BMW i8 sports car, which featured a hybrid system combining a 1.5T three-cylinder engine with an electric motor, delivering explosive performance—though it's a shame it's been discontinued. If you're browsing BMW's compact car lineup at a dealership, models with "18i" or "20i" badges typically indicate three-cylinder configurations.

The three-cylinder model that left the deepest impression on me is definitely the F52 1 Series Sedan, especially the China-market 118i variant with its 1.5T three-cylinder engine paired with a 7-speed dual-clutch transmission. It drives fine under normal conditions, though the engine vibration is slightly noticeable during cold starts. BMW frequently uses this powertrain in entry-level models to control costs, like the domestically produced X1 sDrive18Li which shares the same three-cylinder unit. A word of caution for used car buyers: the 218i variant of the 2 Series Active Tourer produced between 2015-2022 also carries this three-cylinder engine. These models require extra attention to spark plug inspections during maintenance as three-cylinder engines operate at higher temperatures and experience faster wear. Overall, BMW has been phasing out three-cylinder engines in recent new models, now mainly reserving them for some front-wheel-drive platform entry-level products.

Nowadays, there are quite a few people driving three-cylinder cars, especially among young families. Take the BMW X1 for example—there are two sDrive18i models in my neighborhood, both equipped with a 1.5T three-cylinder engine and Magna transmission. The owners report that the urban fuel consumption of over 6 liters is quite cost-effective. The latest 2023 model with this configuration is still available in domestic 4S stores, and the white exterior with beige interior is a particularly popular choice. However, it’s worth noting that the BMW 1 Series Sedan switched to an all-four-cylinder lineup after last year’s redesign, but the compact 2 Series Active Tourer wagon sold overseas still uses a three-cylinder engine. These models typically feature the B38A15C engine, and after prolonged use, it’s advisable to focus on checking the engine mounts, as three-cylinder vibrations are more likely to cause part fatigue compared to four-cylinder engines. While they can’t match the performance of models like the 330i, they are nearly a third cheaper in price.

I remember when visiting a 4S store, the salesperson highly recommended the three-cylinder version, especially for those on a tight budget. For example, the domestic BMW 1 Series Sedan F52 118i, with an out-the-door price of around 220,000 RMB, is several thousand cheaper compared to the four-cylinder 120i. The BMW X1 sDrive18Li has significant on-the-spot discounts, but its engine is the same as the one in the MINI Cooper. I think the biggest hassle with these cars is in winter; when the outdoor temperature drops below zero, the cold start of the three-cylinder engine is noticeably rougher, and you have to wait for the RPM to stabilize before it quiets down. Additionally, when driving on the highway, acceleration response tends to weaken after exceeding 100 km/h, so be mentally prepared for that. If your main use for the car is commuting, you might consider this three-cylinder configuration. However, for friends who enjoy road trips, it's advisable to spend a bit more for the four-cylinder version, as it provides much more confidence when climbing hills with a full load.

The three-cylinder engine is primarily used in compact cars based on the UKL front-wheel-drive platform, with deployment starting from 2014. Based on my experience running a repair shop, common models include the sDrive18i version of the older BMW X1 F48, with the engine code B38. For the newer X1 U11 series, it varies—the entry-level versions still use the three-cylinder, while higher trims have switched to four-cylinders. The BMW 2 Series Active Tourer F46 is particularly notable among three-cylinder models, with a higher likelihood of valve cover oil leaks after 70,000-80,000 kilometers compared to four-cylinder engines. Additionally, the BMW i8 hybrid supercar also counts, as its 1.5T three-cylinder engine impressively delivers 231 horsepower. For used car buyers, models from 2018 onwards are recommended, as BMW improved the balance shaft and soundproofing materials, significantly reducing idle vibrations. Overall, with diligent maintenance, three-cylinder engines can be quite reliable—changing to high-quality full synthetic oil annually can extend their lifespan.


