BMW Z4 vs M340i Comparison Review - Naughty 40ies

This Bavarian duo couldn’t be more different – one is a four-door family sedan, and the other is a two-door sports convertible. Yet, they share a common thread – both are powered by one of the greatest turbo petrol engines of all time – BMW’s B58 3.0-litre six-cylinder powerhouse.

Objectively speaking, it doesn’t make much sense to compare the M340i and Z4 M40i, for they are built for entirely different purposes. However, that ‘M’ badge…well, that’s where the trouble lies. Why, you ask? Well, because that badge signifies that both vehicles have been primarily designed to offer one thing – sheer driving pleasure. So, putting their purposes aside, the question is – which of the two is the more engaging 40i?

BMW M340i Review – The Ultimate Sleeper Performance Sedan

Guess which one’s more expensive between the two? Yes, you’re right – it’s the Z4. Now, guess which one is more powerful and quicker? Well, nope, you’re wrong this time. It’s the M340i!

Would it be fair to say that the M340i is the most complete performance car under a crore? I’d say it is. The M340i is the kind of product that isn’t about asking what you get for your money, but what is it that you don’t? You get my drift? There’s virtually everything that it brings to the table – high performance, impeccable dynamics, four-door practicality, and the latest tech. Plus, when you’re not aiming for the 1/10ths, it’s a luxury sedan par excellence. And the icing on the cake is its phenomenal pricing. The first time I drove the M340i, about four years ago, I called it ‘the bargain M3’. Even after all these years, that statement still holds true.

Now, BMW has tweaked the M340i to make it more user-friendly in India, but it retains the sleeper soul of the original. In short, the star of the show is still the B58 engine, pushing out nearly 370 horses and 500Nm of twisting force. Cutting straight to the chase, the B58 is an absolute firecracker of an engine. Push the pedal to the metal and this engine propels the M340i from a standstill to license-cancelling speeds in no time. What’s more, it can do the 0 – 100km/h sprint in just 4.4 seconds, which not only makes it the fastest accelerating Made-in-India ICE vehicle, but that’s also half a second faster than the legendary V8-powered E90 M3. That’s quite something.

There’s no denying though that it’s not a real M car – which means it often gets slagged, mostly by trolls, on the internet for featuring an M badge. But if you ask me, it feels like an M car 80% of the time. That’s no way a bad deal because while it has the go of an M car, it’s not constantly on edge. In fact, with just a press of a button it turns into a docile luxury sedan. More so in the latest version, since it now gets the M Adaptive Suspension as standard. As a result, the ride isn’t jarring all the time – it’s supple, quiet, and absorbent on bad roads. It feels like a proper luxury sedan – until you turn to Sport or Sport Plus modes. Then all hell breaks loose!

When you’re blasting down a straight, the M340i – with its all-wheel drive or xDrive system – is blistering fast and sticks to the road like a leech. The grip, traction, and stability – all impeccable. Around corners, it’s much the same story. It corners like it’s being driven on rails. The new flat-bottom M steering wheel is direct and precise, and the nose darts around turns without missing a beat. What’s more, the overall composure and adjustability of this chassis is simply remarkable. Classic BMW traits.

But you might argue that it’s not rear-wheel drive. Well, no, it’s not. But, this is still a BMW at heart, which means that the xDrive system unashamedly favours the rear axle. So, while cornering hard, you can always sense the car being pushed and rotated from the back. The handling is delectable, period.

If there’s one slight criticism I have, it’s that the M Adaptive Suspension in the LCI version has made it a little too plush – even in the sportiest of settings, there’s a bit more boy roll compared to the old car. It’s still incredibly sharp for a four-door family sedan, but it doesn’t seem to be fully committed to the cause. Let’s just say that it’s now easier to live with on a daily basis on our roads, and I completely understand why BMW chose to do that.

On the flip side, what has become better, surprisingly, is the noise. This thing is markedly louder than the outgoing version. I distinctly remember being underwhelmed by the whole experience of the previous model – even while driving at the speed of sound, it always felt a little muted inside. But not this one – it growls. It pops and bangs on the overrun, and you don’t have to stick your ear to the exhaust – it’s easily audible in the cabin. Now, of course, you might argue that this is nothing but BMW’s infamous piped-in noises coming through the speakers. However, I rolled down all four windows, stuck my head out, and noticed that it was very much a genuine noise coming straight from the exhaust pipes.

What makes life feel even better in the M340i is its interior. This isn’t a stripped-down performance car on that front – it’s a full-on luxury car instead. You get BMW’s latest iDrive 8.5, along with the new-age Curved Display with two screens. There are all the creature comforts that you get in a regular 3 Series, meaning it’s opulent and tech-laden. Plus, the new Vernasca black leather upholstery, combined with contrast blue stitching and a heavy dose of carbon fibre, is so tastefully done.

The M340i is irresistible, and of that, there’s no doubt. But can it better the Z4 – a two-door sportscar with limitless headroom – as the ultimate driving machine? If you ask me, it’s got its work cut out!

BMW Z4 M40i Roadster Review – Open-Top Thrills

The moment you jump into the Z4, especially after experiencing the M340i, you realise the difference between a performance car and a sports car. In the Z4, everything feels more serious. You sit low, almost on the floor, the seats are narrow, the overall sense of space is tighter, and every control is more driver-focused. The dashboard is tilted towards the driver, the M steering wheel – it’s perfectly round here – is smaller and has a thinner rim, and the pedals are relatively closer to each other.

Now, one important thing to note is that tech and gadgets here are a generation behind what you get in the M340i. So, no curved displays or big screens. What you get instead is the old iDrive 7 with two 10.25-inch screens – one for the infotainment and the other as a driver display. Compared to the M340i, this interior does feel outdated, but we’re not here to play with screens – not on this occasion, at least.

Because the Z4’s cabin feels a generation older, it has a more analogue and old-school charm of the two. Plus, it comes with a proper gear lever, instead of the soulless toggle button / shifter of the M340i. Now, let’s move to the juicier bits. The Z4 does not have an M avatar and thus the M40i is the top-spec version of the roadster that money can buy. Although, if you happen to be anywhere else in the world, there’s something called the Toyota Supra for you, which is based on the same platform as the Z4 – but that’s a story for another day.

In terms of the hardware, the Z4 M40i gets more or less the same kit as the M340i – M Adaptive Suspension, M Sport Differential, M Brakes, and, of course, the B58 firecracker. However, there’s a catch. The Z4’s B58 is offered in a lower state of tune in India, producing 335bhp and 500Nm. A bit of a downer, considering BMW offers it in a more powerful state of tune in global markets. There’s a manual transmission on offer, too, but in India, it’s only offered with the 8-speed ZF auto, the same as the M340i. On the upside, it can still crack 0 – 100km/h in 4.5 seconds, and unlike the M340i, it’s a pure front-engine, rear-wheel drive machine.

If you stomp on the A-pedal in the M340i carelessly, its AWD and long wheelbase ensure that you’re well taken care of. But do the same in the petiter RWD roadster, and it won’t hesitate to throw caution to the wind, resulting in a furious wheel spin and fishtailing. Sure, the traction control and electronics reign it in before you end up embarrassing yourself, but it does send a warning to your senses. It’s lively but in a fiery way.

Once the Z4 gains traction, though, it takes off with blistering speed. There’s no dearth of performance, as it picks up pace quickly, all while making glorious noises. And that difference of 0.1s hardly matters, especially when the roof is down, the sun is shining on your receding hairline, and you feel the full force of Delhi’s filthy air against your face. That’s what a convertible does – it creates a sense of occasion even in such dystopian times.

Surprisingly, the Z4’s exhaust produces understated noises. Even with the roof down, it’s not as loud. However, the induction noise is deeper, and the pops on the overrun are bassier. Put the roof back up – it takes only 10 seconds to open or close the roof – and it becomes even more muted. However, if you do a rev battle at a standstill, it’s the Z4 that produces a throatier and louder noise.

In the handling department, the Z4 is every bit a sports car, and then some. The nose is sharp, and it’s more agile for obvious reasons. Despite being RWD, the traction is phenomenal. It never loses composure around corners regardless of how hard you push it. There’s some movement at the back when you turn the TC off, but to break traction and slide – and to catch the tail back again – you would have to be a driving god! It’s unshakeable. This is also down to its tyres. While both the M340i and Z4 feature 19-inch staggered set, the latter gets fatter tyres – 255/275 vs 225/255 at the front and rear. The wider contact patch makes all the difference.

Then there’s the suspension. The Z4 has a stiffer setup, and you can feel it when you’re pushing it around corners. However, its roadholding isn’t as impeccable as the M340i, for the Z4 tends to hop and skip when the surface isn’t silky smooth. There’s also a lot of side-to-side movement, and it feels excessively rigid in its Sport modes. The steering is direct, but it’s got an artificial heft unlike the M340i, which feels better weighted and consistent through and through. It’s a similar story with the gearbox. The ZF 8-speeder is identical in both vehicles, but it offers snappier shifts, especially in manual mode, in the M340i.

Much like the M340i, the Z4 can go from being a rowdy machine to a gentle luxury car in no time. Despite having a soft top, the noise insulation is impressive, and the overall refinement is simply brilliant. What’s more, in Comfort mode, the suspension is supple and the ride isn’t bone jarring. In fact, for a sports car, it’s surprisingly easy to live with, even on Indian roads. Even the ground clearance is decent. The only thing you have to deal with is the attention it garners – it’s an outright head-turner.

BMW Z4 vs M340i – Which 40i You Should Buy?

Having driven both the 40is to my heart’s content, I can convincingly tell you that there’s no loser here. They are both fantastic driver’s cars, with a lot of character and charisma. That said, if you put a gun to my head, along with a crore in my bank account, I’ll give you a clear winner in terms of sheer thrills. It’s the M340i. Not only is the B58 drivetrain livelier, louder, and more engaging in the M340i, but it’s also more playful in terms of driving dynamics. The fact that it happens to be a four-door practical sedan and considerably more affordable than the Z4 only makes the whole deal sweeter.

As for the Z4, it may not be an outright driver’s delight as the M340i, but it has a greater sense of occasion for sure. And in terms of performance and handling or sheer driving thrills, it trails the M340i only by a whisker or so. But that’s precisely it – it trails its four-door siblings, and not leads. So, from a driver’s perspective, it’s the M340i, which is the better 40i of the two. This also means that, for me, the M340i is now also the most exciting car under a crore, in addition to being the most complete.