M135i xDrive F40
The BMW M135i xDrive F40 features turbocharged B48 2.0-liter inline four-cylinder producing 306 horsepower (225 kW) from 4,500-6,250 rpm and 332 lb-ft torque (450 Nm) from 1,750-5,000 rpm through eight-speed Steptronic Sport transmission with race start mode and xDrive all-wheel-drive system, achieving 0-62 mph in 4.8 seconds and electronically limited 155 mph top speed at 1,647 kg weight. Larger turbocharger, optimized intake routing, high-performance cooling package, and flap-controlled M exhaust system create most powerful series-production BMW four-cylinder configuration.
F40 generation represents controversial departure from previous rear-drive M Performance 1-Series models, adopting front-drive-based UKL2 platform with xDrive all-wheel-drive and transverse engine layout shared with MINI and 2-Series Active Tourer. Despite enthusiast criticism regarding platform architecture change, M135i xDrive delivers genuine performance credentials through turbocharged power delivery and sophisticated all-wheel-drive traction, though traditional BMW M division philosophy of rear-drive handling balance sacrificed for practical packaging efficiency and manufacturing cost reduction across BMW compact car portfolio.