BMW uprated the X3 SUV back in 2021, with sportier styling, more equipment, and mild-hybrid technology to improve fuel economy and reduce emissions.

The M40d is the most powerful diesel in the range, with 340hp and 516lb ft of torque. It’s also heavy for a mid-sized SUV, with a kerbweight of over two tonnes.

Standard equipment is generous – as it should be with an asking price that falls the wrong side of £60,000.

What are we looking for?

The M40d needs to be very capable indeed to justify its premium pricing, when less expensive X3 models are strong tow cars in their own right. Is the M40d the car enthusiast’s choice, or will it also appeal to regular drivers who are less concerned about performance?

Towing ability of the BMW X3 M40d

If you believe that you can never have too much of a good thing, you’ll love towing with the X3 M40d.

The engine is the star of the show, with its colossal power and torque figures. BMW sets a towing limit of 2400kg, but it would probably tow your house if you could fit some wheels under it.

Certainly it has no trouble pulling any sensibly matched home-from-home. With a kerbweight of 2080kg, the BMW has an 85% match figure of 1768kg. We matched it to a Swift Fairway Platinum Grande 580 with a MiRO of 1505kg. The BMW towed it with ease. We never needed to use more than half throttle, usually much less.

Holding speed on hills is straightforward, and at 60mph in top gear, the engine is pulling around 1250rpm.

What’s also impressive is how well the X3 puts its power to the road, something the best tow cars will always deliver. BMW’s xDrive four-wheel-drive system makes for smooth and clean getaways, so you can use the car’s performance without any wheelspin.

A hill-start on a 1-in-10 slope was easy, even on damp Tarmac.

We’d always take stability over speed, but the M40d delivers both. The tow car’s suspension is firm, even with the adjustable damping set to Comfort, which helps it tow straight and true. Crosswinds and high-sided vehicles caused no trouble. The only wobble we experienced was when a large van overtook us, passing within inches of the caravan at well over the speed limit. Even then, the X3 quickly pulled the van straight again.

However, the best SUV tow cars will also be easy to manoeuvre at low speeds, and that’s the case with this BMW. The accelerator has plenty of travel, which makes it simple to reverse slowly to the caravan when hitching up.

The towball drops down and retracts at the press of a button that’s hidden behind a panel in the boot. This did take a bit of searching to find the first time, and we can’t see any obvious advantage to having the button tucked out of sight.

The towball drops down and retracts at the press of a button that’s hidden behind a panel in the boo

The electrics sit to the side of the towbar and are easy to access without the bumper getting in the way.

Fitting towing mirrors can be rather a challenge with BMWs, because the door mirror housings tend to have bevelled edges. We found that the current model Milenco Grand Aero Platinum, with its flexible rubber grippers, would fit, so long as we mounted them carefully.

The M40d really is an excellent tow car, combining a high kerbweight with effortless performance, the all-weather security of four-wheel drive, and robust stability. From past experience, we know more affordable models offer similar abilities.

Solo driving a BMW X3 M40d

Just as when towing, the mighty 3.0-litre diesel dominates the driving experience in everyday travel. With its deep grumble, it sounds quick even when cruising.

BMW claims a 0-62mph time of just 4.9 seconds, making this one of the fastest cars we’ve ever tested.

Use full throttle and the M40d leaps forward, and moments later you’ll need to ease off to avoid breaking the speed limit.

It comes with adjustable suspension as part of the Driving Dynamics system, which also alters the throttle, gearbox and steering.

Even in Comfort mode, the M40d rides quite firmly. Together with the big 21-inch wheels and low-profile tyres, the sporty suspension means you do feel bumps in the road, especially at low speeds. The trade-off is impressive control at speed.

On country roads, the X3 is very satisfying to drive. Switching to Sport adds some heft to the steering and quicker responses from the gearbox, although the eight-speed auto is hardly tardy to start with.

It corners with poise and precision, but we’d be surprised if the equivalent BMW 3 Series Touring wasn’t even more fun, thanks to carrying its weight closer to the road. For a high-riding two-tonne SUV, though, the M40d is nimble and responsive.

Driven more sedately, the firm ride is really the only compromise to the car’s comfort. There’s a little road noise at motorway speeds, but otherwise the cabin is hushed, and engine noise stays in the background when the M40d is driven gently.

Space and practicality in the BMW X3 M40d

With a budget around £60,000, you can buy many bigger SUVs than the X3, and plenty with seven seats. But if room for five is plenty, this is a practical car.

There’s a lot of space in the front, with enough legroom for drivers well over 6ft tall. Both steering wheel and driver’s seat have scope for fine-tuning the driving position. The seats offer good support while cornering without feeling too restrictive.

A digital display is fitted, rather than conventional dials. The driver can customise the information on show, and the appearance changes with the different driving modes.

Cockpit of tow car
A digital display is fitted, rather than conventional dials, and the driver can customise the information on show

The infotainment screen is large and clear. Although you can touch the screen to move through the menus, it was easier to use the iDrive rotary controller to the side of the gearlever. We found this less distracting while driving.

The back of the car is very spacious, although the big transmission tunnel will get in the way if there are three rear-seat passengers.

Rear seats
The back of the car is very spacious – note the two-tone leather is a cost option and single-colour upholstery is included in the price

Legroom is sufficient for adults, even if the driver and front-seat passenger are tall. Headroom is also plentiful, even though our test car was fitted with a panoramic sunroof (£1190). Air vents between the front seats keep everyone cool, and a couple of USB-C ports keep devices charged up.

Side on of BMW X3 M40d
There’s a lot of space in the front, with enough legroom for drivers well over 6ft tall, and scope for fine-tuning the driving position

With the back seats upright, the luggage capacity is 550 litres. That’s on a par with the Audi Q5. Folding the seats and removing the parcel shelf increases this to 1600 litres.

If you need to carry longer items, and have two passengers in the back, the centre seat folds down independently.

Rear of BMW X3 M40d
For a family of four, the BMW provides plenty of space for people and their luggage

It’s worth noting that the two-tone leather in our test car is a £990 extra. There’s a choice of less garish single-colour leather included in the price.

Buying and owning a BMW X3 M40d

You do pay a premium for the M40d’s rapid performance. With a price tag of £62,785, it costs over £7000 more than the X3 30d M Sport, which has 286hp and is less than a second slower to 62mph. The 190hp X3 20d M Sport is a further £6000 cheaper and tows superbly.

It’s not just the high up-front cost to consider, though. The less powerful diesels hold their value better than the M40d, according to What Car?.

They will be cheaper to fuel, too, although the M40d is very frugal for such a quick, heavy car. With mild-hybrid assistance reducing the strain on the engine, we saw 41-43mpg in everyday driving, and 25.2mpg while towing the caravan.

The M40d is well equipped, with 21-inch alloys, acoustic glass (to reduce noise), zoned climate control, heated front seats, leather upholstery, a rear parking camera, and Apple CarPlay and Android Auto.

The X3 scored the maximum five stars when it was tested by Euro NCAP, and a wide range of safety kit is standard.

With a choice of packs and options, it’s easy to push the price higher. The one essential for caravanners is the towbar and electrics, priced at £850.


The X3 is a superb tow car. The trouble is, that applies to any X3, not just the M40d. You will have heard the expression about using a sledgehammer to crack a nut? Well, the M40d is more like a pneumatic drill.

You need to relish the idea of reaching 62mph in less than five seconds to choose the M40d over other models in the range. Even for the most enthusiastic drivers, the 286hp 30d is powerful enough to put a smile on your face – and tow heavy caravans. And the 190hp 20d is much more affordable and won’t seem underpowered, unless you own a very heavyweight tourer.

But if you have the means, the M40d’s performance is addictive. And while the ride is firm, it’s not so stiff as to make the car uncomfortable in normal driving. It’s as happy on the commute or school run as it is on a favourite B-road.

Inside, the X3 is comfortable and roomy. Yes, you can buy some luxurious seven-seaters for the same money, but not with performance to match the M40d’s. And for a family of four, the BMW provides plenty of space for people and their luggage.

The running costs aren’t crazy for a vehicle this fast. We found the official combined figure of 40.9mpg to be easily achievable in regular driving, and 25.2mpg is a reasonable return while towing.

If we were offered the keys to any of the X3 range, we would choose the M40d. But if we were spending our own money, we’d pick one of the more sensible models.

Or you could try:

Technical spec

  • Price: £62,785
  • What Car? Target Price: £60,957
  • Retained value after three years: 48%
  • Kerbweight: 2080kg
  • 85% of kerbweight: 1768kg
  • Gross vehicle weight: 2580kg
  • Max towing limit: 2400kg
  • Gross train weight: 4980kg
  • Towball limit: 100kg
  • Price of towball and electrics: £850
  • Boot size min/max: 550/1600 litres
  • Payload: 500kg
  • Test conditions: Damp
  • Engine size: 2993cc
  • Official combined economy: 40.9mpg
  • Towing economy: 25.2mpg
  • Power (hp)/rpm: 340/4400
  • Torque (lb ft)/rpm: 516/1750-2250
  • CO2 emissions: 181g/km
  • First year car tax: £935
  • Second year car tax: £510
  • Insurance group: 43E
  • Euro NCAP overall protection rating: 5/5

If you’ve enjoyed reading this article, why not get the latest news, reviews and features delivered direct to your door or inbox every month. Take advantage of our brilliant Practical Caravan magazine SUBSCRIBERS’ OFFER and SIGN UP TO OUR NEWSLETTER for regular weekly updates on all things caravan related.