Forbidden Fruit: BMW M340d Touring Review, The Effortless Diesel Wagon

The BMW M340d xDrive Touring combines near-M340i performance with long-distance diesel efficiency, making it one of the most complete 3 Series models BMW sells.

Pros

• Fast, efficient, all-weather wagon that can cover serious distance with very little effort.
• Excellent real-world range, making it as much about distance as performance.
• SUV-like practicality without the higher ride height or softer driving dynamics.

Cons

• The diesel inline-six does not have the same sound or emotion as BMW’s gasoline inline-six.
• The ride can feel firm, especially depending on wheel size and road surface.
• Modern diesel hardware, mild-hybrid tech, and BMW maintenance can add complexity and cost.

Some forbidden fruits can be exotic, impractical, or impossible to justify. The BMW M340d xDrive Touring is different: it feels like the 3 Series wagon North America should never have lost, but stricter emissions rules, Dieselgate, and the rise of hybrids and EVs pushed it off the road.

The frustrating part is that BMW already proved this formula could work in North America. We once had the 328d xDrive Sports Wagon in the U.S. and the 328d xDrive Touring in Canada. It was not as powerful or as special as this M340d, but it delivered the same formula: diesel efficiency, all-wheel drive, wagon practicality, and proper BMW road manners.

The M340d Touring has near-M340i performance, long-distance diesel range, and the kind of useful cargo space crossovers keep trying to replace. The real frustration was not that BMW still builds a car like this. It was realizing how well it works.

A Proper Long-Distance Machine

The M340d Touring immediately felt at home on the road. On unrestricted sections of autobahn, it had no issue settling into high speeds while still feeling planted, stable, and relaxed. We stretched it close to its top speed, yet even at around 200 km/h and beyond, it never felt like it was working hard. That is what makes this car so impressive: it is not just quick, it is composed at speed. The diesel inline-six does not chase drama, but it delivers a huge wave of torque that makes high-speed cruising feel effortless.

More impressively, that same character did not disappear once the route moved from autobahn speeds to alpine climbs and the wine roads of Southern Austria. Around Grossglockner, the M340d never felt overwhelmed. It is not a lightweight sports car, but it hides its weight well. The steering is precise, the xDrive system gives it proper grip, and the torque makes steep sections feel almost too easy.

The Diesel Advantage

The biggest argument for the M340d Touring is not just fuel economy. It is how little performance you give up to get it. On paper, the diesel Touring is only 0.2 seconds slower to 100 km/h than the gasoline M340i xDrive Touring. On the road, that gap feels irrelevant because the M340d still pulls hard, still feels quick, and still has more than enough performance to justify the M badge.

The real difference comes after the acceleration run. After a mix of autobahn driving, mountain roads, and regular European roads, we averaged around 6.5 L/100 km. For a fast, all-wheel-drive wagon driven properly, that number is hard to ignore.

Diesel still comes with trade-offs. Maintenance can be more expensive, diesel exhaust fluid is part of the ownership experience, and it makes more sense for longer drives than short city trips. But if you regularly cover highway kilometres, the M340d makes a strong case for itself.

A gasoline performance wagon can easily climb above 9 L/100 km in similar use. The diesel’s advantage is not just saving fuel. It is travelling farther, stopping less often, and giving up very little performance along the way.

Mild-Hybrid Smoothness

The 48-volt mild-hybrid system helps the M340d feel more refined. One of the nicest details is how the car can sail or coast when conditions allow it. Lift off the throttle and, instead of always dragging the engine along, the car can glide with very little resistance.

This powertrain makes highway driving feel smoother and more efficient. It also suits the car’s personality perfectly. The M340d is quick when you ask it to be, but when you are just covering distance, it becomes quiet, relaxed, and easy to live with.

Interior: Familiar, Premium, and Actually Useful

Inside, the M340d Touring feels like a proper BMW: excellent driving position, supportive front seats, and a cabin built around the driver without ignoring the passengers. The front seats are comfortable for long highway days but still hold you well when the road starts twisting, while rear-seat space is good for a compact luxury wagon. Adults can fit, kids will be perfectly happy, and the Touring body makes the car far more useful than a sedan without turning it into an SUV.

The cargo area is also one of the reasons this body style makes so much sense. It is low, easy to access, and shaped in a way that makes the space genuinely usable. But the detail I really like is the separately opening rear glass. Instead of opening the entire tailgate every time, you can pop the glass open and quickly drop smaller items into the trunk or reach something without disturbing the whole load.

It is a small feature, but it makes a big difference in daily use. When the trunk is packed for a trip, it gives you another way to fit one more bag, jacket, or backpack into the space. It also makes it easier to grab something quickly when the car is parked close to a wall or another vehicle.

What Could Be Better

As good as the M340d Touring is, it is not perfect. The emotional side is slightly restrained. The diesel inline-six is smooth, powerful, and seriously efficient, but it does not deliver the same sound or character as BMW’s gasoline inline-six. It is fast, but not theatrical.

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The ride can also feel firm depending on the road surface and wheel setup. It is never harsh, but on broken pavement, you are reminded that this is still an M Performance model.

The price and complexity matter too. Between the diesel hardware, mild-hybrid system, xDrive, and premium BMW maintenance, this is not a cheap car to own. The efficiency is excellent, but buyers need to drive enough to make the diesel advantage worthwhile.

Final Thoughts

The BMW M340d xDrive Touring is one of those cars that makes more sense the more you drive it, because its strengths add up quickly in the real world.

On paper, it may not look as exciting as an M3 Touring or as trendy as an electric SUV. But in the real world, across highways, mountain roads, family use, and long European distances, it feels incredibly complete.

That may also be what makes it feel so important. The next M Performance 3 Series is expected to move toward the M350 name, and while BMW has not confirmed the future of the M340d, a direct diesel successor is far from guaranteed.

If this really is one of the last fast diesel 3 Series wagons, it makes the M340d Touring even harder to ignore. It is fast without being exhausting, efficient without being boring, and practical without feeling like a compromise.