The 2018 BMW X5 represents a significant evolution for BMW’s mid-size luxury SUV, marrying robust performance with everyday practicality. Under the hood, buyers found a refined selection of powertrains designed to balance power, efficiency, and driving dynamics. Understanding the engine options available for this model year is essential for anyone considering a used example or simply appreciating German engineering from this era.
S40i and xDrive40i: The Mainstream Powerhouses
For the majority of buyers, the 2018 X5 lineup started with the efficient yet capable sDrive40i and all-wheel-drive xDrive40i trims. These models were powered by a 3.0-liter turbocharged inline-six engine, a powerplant renowned for its smoothness and reliability. Producing 300 horsepower and 300 pound-feet of torque, this mill delivered confident acceleration while maintaining decent fuel economy for the segment. The inline-six configuration is inherently balanced, resulting in a vibration-free experience that BMW is famous for, making daily driving a pleasure rather than a chore.
The Inline-Six Advantage
Unlike a traditional V6, the inline-six layout places all cylinders in a single row. This design allows for a lower center of gravity and contributes to the silky-smooth operation that enthusiasts appreciate. The turbocharger in the 2018 model ensures that power is available across the rev range, providing that familiar BMW responsiveness the moment you press the accelerator. This engine choice perfectly encapsulates the brand’s philosophy of "Ultimate Driving Machine" applied to an SUV platform.
M60i and X5 M: The High-Performance Contenders
Those seeking a more aggressive experience were catered to with the M60i Performance and the full-blooded X5 M models. The M60i, sitting above the standard xDrive model, featured a twin-turbocharged 4.4-liter V8 that produced a formidable 523 horsepower. This surge of power allowed the luxury SUV to sprint to highway speeds with effortless ease, accompanied by the intoxicating sound of a high-revving V8. The X5 M, however, was in a different league entirely, representing BMW’s top-tier performance SUV.
X5 M: 4.4-liter twin-turbo V8 producing 600 horsepower and 553 pound-feet of torque.
M60i: 4.4-liter twin-turbo V8 producing 523 horsepower and 553 pound-feet of torque.
Both models featured M-specific suspensions and aggressive styling to distinguish them from the mainstream trims.
Transmission and Drivetrain Dynamics
Regardless of the engine chosen, the 2018 X5 utilized an 8-speed automatic transmission supplied by ZF. This unit is widely regarded as one of the best in the business, offering lightning-fast shifts and seamless integration with the engine control unit. The transmission logic is intelligent, holding gears for normal driving to preserve fuel efficiency and downshifting proactively when the driver demands excitement. Furthermore, the available xDrive all-wheel-drive system meticulously distributes power between the front and rear wheels, ensuring exceptional traction in various weather conditions.
Fuel Economy and Practical Considerations
While the X5 is not a compact car, BMW made significant strides in improving its efficiency during the 2018 model year. The base 40i models, thanks to their smaller inline-six and available start-stop technology, managed to achieve an EPA-estimated 21 city / 26 highway MPG. The higher-performance variants, particularly the X5 M, naturally consumed more fuel, with estimates hovering around 15 city / 21 highway MPG. Owners consistently praise the real-world fuel economy, noting that it aligns well with the EPA estimates, especially during steady highway cruising.
