BMW M340i takes the everyday usefulness of the 3 Series and adds the kind of performance that can make an ordinary highway entrance surprisingly entertaining. Its B58 3.0-liter turbocharged inline-six produces around 382 hp and 369 lb-ft of torque, giving you substantially more power than the 330i while preserving seating for five and a comfortable cabin. An 8-speed sport automatic handles shifting. Depending on model year and market, you can find rear-wheel drive or xDrive all-wheel drive, along with a 48-volt mild-hybrid system on newer versions. Acceleration can drop to roughly 4.0 seconds from 0–60 mph with xDrive, putting the M340i firmly into serious performance territory. M Sport chassis upgrades, stronger brakes, performance tires, and sharper suspension tuning support that extra speed. You still get around 13 cu ft (368 L) of trunk capacity and the comfort needed for commuting or longer trips. That combination is the M340i’s main attraction. You get considerably more performance than a regular 3 Series without giving up the usefulness you need when you are not driving simply for fun.
Sitting above the 330i and 330i xDrive, BMW M340i serves as the M Performance choice in the 3 Series range rather than a full M3. That distinction matters when you are deciding how much performance you actually want to live with every day. M340i upgrades the engine, suspension, steering, brakes, wheels, tires, exterior details, and other performance hardware while retaining a more everyday character than the M3. Rear-wheel drive is offered in the US during applicable model years, while xDrive all-wheel drive is available in both US and Canadian configurations. For buyers dealing with snow or frequent wet roads, xDrive can make the 382 hp easier to put down. Rear-wheel drive appeals to drivers who prefer a more traditional sport-sedan layout. Either way, you are buying a substantial performance step above the 330i. If you want a quicker 3 Series without moving all the way to the M3’s more specialized setup and higher running costs, the M340i fills that space.
Lift the hood and much of the BMW M340i’s appeal becomes easy to explain. BMW’s B58 3.0-liter turbocharged inline-six produces around 382 hp and 369 lb-ft of torque, with an 8-speed automatic transmission managing the power. Recent versions also use a 48-volt mild-hybrid system, depending on model year. You get smooth acceleration at lower speeds and a strong surge when you ask for more power. Having six cylinders arranged in a straight line also contributes to the smooth character that separates the M340i from many four-cylinder alternatives. xDrive sends power through all four wheels, while applicable rear-wheel-drive versions retain the traditional rear-drive layout. Strong performance does make maintenance more important. Keep oil changes and scheduled servicing current, use the correct fluids, and investigate warning lights rather than hoping they disappear permanently after restarting the car. The B58 has earned a strong reputation, but even a respected performance engine still needs proper care. Nearly 400 hp has a funny way of making neglected maintenance more expensive.
| Specification | BMW M340i |
|---|---|
| Engine | B58 3.0L turbocharged inline-six |
| Horsepower | Around 382 hp |
| Torque | Around 369 lb-ft |
| Transmission | 8-speed sport automatic |
| Drivetrain | RWD or xDrive AWD |
| Mild Hybrid | 48-volt system, year-dependent |
| Fuel Type | Gasoline |
| Configuration | Front engine, rear-drive or all-wheel drive |
Put your foot down and the BMW M340i separates itself from the 330i almost immediately. Rear-wheel-drive versions can reach 60 mph in around 4.1 seconds, while xDrive can cut that figure to approximately 4.0 seconds. Canadian acceleration to 100 km/h is around 4.2 seconds. Those numbers place the M340i much closer to dedicated performance cars than its four-door shape might suggest. Speed is supported by sport-tuned suspension and steering, along with an M Sport differential that is available or standard depending on model year. Top speed is electronically limited and varies with the installed tire package. Strong acceleration also makes tire and brake condition particularly important when you shop used. A car capable of reaching highway speed in roughly four seconds needs quality rubber and healthy brakes. Check tread depth, tire age, matching tire specifications, rotor condition, and brake-pad life before buying. Performance is enjoyable. Discovering that your new purchase immediately needs four premium tires and a brake job is considerably less exciting.
| Performance Measure | Approximate Figure |
|---|---|
| 0–60 mph, RWD | 4.1 seconds |
| 0–60 mph, xDrive | 4.0 seconds |
| 0–100 km/h | 4.2 seconds |
| Horsepower | 382 hp |
| Torque | 369 lb-ft |
| Top Speed | Electronically limited, tire-package dependent |
Fuel economy is surprisingly reasonable when you consider that the BMW M340i produces around 382 hp, although you will use more fuel than you would in a 330i. US EPA figures are approximately 23 mpg city and 32 mpg highway with rear-wheel drive. xDrive comes in around 23 mpg city and 31 mpg highway. Canadian NRCan estimates are roughly 10.7 L/100 km city and 7.4 L/100 km highway for rear-wheel drive, increasing to about 11.1 L/100 km city and 7.7 L/100 km highway with xDrive. Wheel size, tire choice, traffic, weather, and driving style can all move your real consumption away from those numbers. The 48-volt mild-hybrid system fitted in applicable newer models also contributes to efficiency and smoother operation. You can check US model-year ratings through FuelEconomy.gov and Canadian figures through Natural Resources Canada’s fuel consumption ratings. If fuel cost matters to your budget, calculate annual consumption using your actual yearly mileage rather than judging the car from highway MPG alone.
| Configuration | City | Highway |
|---|---|---|
| RWD, US | Around 23 mpg | Around 32 mpg |
| xDrive, US | Around 23 mpg | Around 31 mpg |
| RWD, Canada | Around 10.7 L/100 km | Around 7.4 L/100 km |
| xDrive, Canada | Around 11.1 L/100 km | Around 7.7 L/100 km |
Open the door and BMW M340i reminds you that performance is only half of its job. You still get the premium cabin expected from a 3 Series, but M Performance details give the interior a sportier character. A digital instrument cluster uses M-specific graphics, while the central infotainment system runs iDrive 7 or iDrive 8 depending on model year. Apple CarPlay and Android Auto provide smartphone connectivity. Upholstery ranges from premium synthetic material to optional leather, and Canadian models include heated front seats as standard equipment. Heated seats can be optional on US configurations. Depending on equipment, you can also find a heated steering wheel, ambient lighting, head-up display, aluminum or dark interior trim, and other comfort upgrades. An M Sport steering wheel adds a more performance-focused touch directly in front of you. When shopping used, test every screen, seat function, camera, steering-wheel control, and climate setting. A long equipment list is useful only when everything on that list actually works.
Look beyond the familiar 3 Series shape and several details identify the BMW M340i as the more serious performance trim. An M Sport body kit changes the front and rear styling, while black or Shadowline exterior trim gives the car a darker appearance than many standard 330i configurations. Wheel sizes generally measure 18 or 19 inches depending on year and equipment, with performance-oriented tires fitted to support the additional power and chassis tuning. M Sport brakes use larger performance hardware and can feature blue or red calipers. LED headlights and taillights provide modern lighting, while power-folding mirrors add useful convenience in tight parking spaces. Larger wheels deserve attention when you are buying used because cosmetic damage and tire replacement costs can add up quickly. Check every wheel for bends, cracks, curb marks, and uneven tire wear. Performance tires can also wear more quickly than ordinary touring tires, particularly if the car has been driven enthusiastically. Those handsome 19-inch wheels look considerably less charming when two of them are bent.
Keeping nearly 400 hp manageable requires more than acceleration hardware, so BMW M340i combines its performance with a useful collection of safety and driver-assistance systems. Standard equipment includes Forward Collision Warning, Automatic Emergency Braking, Lane Departure Warning, a rearview camera, and parking sensors. Blind Spot Monitoring is standard in Canada and can be package dependent on US versions. Available systems include adaptive cruise control, lane-keeping assistance, a surround-view camera, Parking Assistant, and year-dependent highway driving assistance. Exact equipment can change by model year and package, which makes checking the actual vehicle important when you shop used. Test the cameras and parking sensors. Make sure there are no persistent driver-assistance warnings on the instrument display. US buyers can check applicable model-year crash-test and recall information through the National Highway Traffic Safety Administration. Canadian buyers can use Transport Canada for recalls and vehicle-safety information.
Measure the BMW M340i against ordinary family duties and you find essentially the same useful compact-sedan footprint that makes the broader 3 Series easy to live with. Overall length is around 185.7 inches (472 cm), while the 112.2-inch (285 cm) wheelbase gives the car enough cabin length for five seating positions. Width is approximately 71.9 inches (183 cm), and height is around 56.8 inches (144 cm). Sport suspension tuning can cause minor ride-height differences depending on configuration. Trunk volume remains around 13 cu ft (368 L), giving you useful space for groceries, work bags, luggage, or other everyday cargo. Rear-seat room works well for a compact luxury sedan, although taller passengers will naturally have less space than they would in a larger sedan. If you regularly carry bulky items, test them before buying. A trunk can measure 13 cu ft on paper and still lose an argument with an awkward stroller or oversized suitcase.
| Measurement | US | Metric |
|---|---|---|
| Seating | 5 | 5 |
| Trunk Volume | Around 13 cu ft | Around 368 L |
| Wheelbase | Around 112.2 in | Around 285 cm |
| Length | Around 185.7 in | Around 472 cm |
| Width | Around 71.9 in | Around 183 cm |
| Height | Around 56.8 in | Around 144 cm |
| Common Wheel Sizes | 18–19 in | 46–48 cm |
Few things explain the BMW M340i better than a road with an empty passing lane ahead. Turbo response is immediate enough to make overtaking effortless, while the B58 inline-six builds power smoothly instead of delivering one sudden shove and running out of breath. Sport-tuned suspension and steering give you sharper responses than the 330i, yet the car remains comfortable enough for commuting and long highway trips. xDrive adds traction when you accelerate hard or encounter wet and snowy conditions. Rear-wheel drive gives applicable US versions a more traditional sport-sedan feel. High-speed stability is another strength, particularly when the tires and alignment are in good condition. You do not need to drive aggressively to appreciate the difference. Smooth power delivery, confident steering, strong brakes, and controlled body movement are noticeable during ordinary driving too. If winter weather is part of your routine, remember that xDrive cannot replace proper winter tires. Four driven wheels help you get moving. Four good tires help you steer and stop.
Reliability should still influence your decision even though the BMW M340i’s B58 engine has built a strong reputation for durability and refinement. Owner-reported concerns can include occasional electronic or sensor warnings, infotainment software glitches, brake wear, minor interior trim noises on older vehicles, and faster tire wear from performance-oriented rubber. Higher performance also means previous ownership matters. A well-maintained M340i that received regular oil changes and timely servicing is a much safer prospect than a lower-mileage car with missing records and obvious signs of hard use. Check service history, tire condition, brake life, warning messages, fluid leaks, and evidence of modifications before buying. A pre-purchase inspection becomes especially valuable if the vehicle has been tuned or altered. Maintenance priority is simple. Confirm routine servicing has remained current even when mileage is relatively low. Performance cars can spend fewer miles commuting and considerably more of those miles being driven hard.
Owning a BMW M340i costs more than owning a 330i because 382 hp brings additional expenses along with the additional entertainment. Fuel consumption is higher, insurance can cost more, and 18-inch or 19-inch performance tires are generally more expensive to replace than ordinary sedan tires. M Sport brake components can also raise brake-service costs. Your exact expenses depend heavily on model year, location, annual mileage, driving history, tire choice, and how aggressively the car has been driven. Depreciation can make a used M340i attractive because an earlier owner may already have absorbed part of the initial value loss, while demand for used M Performance models can support resale interest. BMW maintenance plans can reduce applicable early ownership costs, but you should still keep money available for tires, brakes, scheduled maintenance, and unexpected repairs once coverage ends. Before buying, price an insurance policy and inspect wear items. A monthly payment tells you what it costs to finance the car. It does not tell you what it costs to own one.
| Ownership Area | What Changes With the M340i |
|---|---|
| Fuel | Higher consumption than the 330i because of greater performance |
| Insurance | Can be higher because of power, vehicle value, location, and driver profile |
| Tires | 18-inch or 19-inch performance tires can increase replacement costs |
| Brakes | M Sport hardware can cost more to service and replace |
| Maintenance | Premium-brand servicing generally costs more than mainstream alternatives |
| Depreciation | Initial value loss can benefit used buyers, while demand supports desirable examples |
| Repairs | A dedicated repair reserve becomes more important as mileage and age increase |
Cross-shopping the BMW M340i puts you into a group of sedans that approach performance in noticeably different ways. Audi S4 offers another turbocharged luxury performance sedan with all-wheel-drive capability. Mercedes-AMG C 43 places its own emphasis on speed, technology, and aggressive styling. Genesis G70 3.3T provides strong power and generous equipment, while Lexus IS 350 F Sport offers a different balance of performance and luxury. Acura TLX Type S adds another all-wheel-drive alternative for US and Canadian buyers. M340i counters with approximately 382 hp, 369 lb-ft of torque, available xDrive, and 0–60 mph performance of roughly four seconds. Those numbers matter, but they should not make the entire decision for you. Compare seating comfort, trunk usefulness, ride quality, insurance, tire prices, local servicing, and the equipment fitted to each car. A tenth of a second is exciting on a specification sheet. Comfortable seats may matter considerably more during your 500th commute.
Deciding whether the BMW M340i fits you comes down to how much performance you want without moving into the more specialized M3. Around 382 hp and 369 lb-ft of torque can push xDrive versions to 60 mph in roughly 4.0 seconds, while Canadian acceleration to 100 km/h is about 4.2 seconds. Despite that performance, highway economy remains around 31 to 32 mpg in US ratings or approximately 7.4 to 7.7 L/100 km in Canadian figures. You still get five seats, roughly 13 cu ft (368 L) of trunk space, modern infotainment, available driver-assistance technology, and a cabin comfortable enough for regular commuting. Higher tire, brake, insurance, and fuel expenses are the tradeoff, so checking those costs before buying can prevent an unpleasant surprise later. If you want smooth inline-six power, serious acceleration, sharper handling, and everyday comfort in the same sedan, the M340i gives you a compelling combination without requiring the full jump to an M3.
This platform analyzes depreciation trends, resale value behavior, and long-term ownership costs, helping drivers understand how mileage, maintenance, and timing shape real financial outcomes.
