BMW i4 vs M340i comparison: An eye for an i

BMW’s i4 is both electric and a real hoot to drive. But is it better than the carmaker's similarly priced M340i? We took the pair to some good driving roads to find out.

Published On Oct 02, 2022 10:00:00 AM

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It’s a damp, wet monsoon day. The kind where spells of lashing rain and strong gusts of wind make it difficult to venture out of the car. With no camera work possible and nothing else to do, we set off for a drive. The conditions aren’t ideal, but there’s no standing water on the road and traffic is thin.

BMW i4 vs M340i: ride and handling

BMW’s i4 has been the perfect companion on the journey up from Mumbai. Light, easy and fatigue-free to drive, it is an energetic car that clearly has been engineered to drive well. The steering is direct and super accurate, and the i4 responds smartly to a tap on the throttle without overreacting like many electrics do, and the large driver’s seat keeps me comfortable on the long drive.

i4’s grille divides opinion, but there’s no denying it looks dramatic.

What makes it even more agreeable is that the ride is flat and super comfy. Supple, silent and capable of taking the edge off most medium and small sized bumps, the i4 glides over even damaged and broken surfaces with ease. And not only is the suspension absorbent, the ride is flat too; the wheels only pitter-pattering in a controlled manner over bad sections of road, with very little tossing or pitching.

But is it any wonder? The front steel and rear air spring set-up is something BMW has perfected earlier. And here, on the i4 40, with no heavy engine over the front axle; the heavy battery between; and the e-motor over the rear axle, it pitches and bobs very little.

BMW has done a superb job in making the i4 a real driver’s car.

The rear-wheel-drive i4 is, in fact, one of the few BMWs that doesn’t have a 50:50 front-rear weight distribution. Here, 45.1 percent of the weight sits over the front axle and 54.9 percent sits over the rear. And having more weight pressing down over the driven axle is great for traction. Just ask Porsche.

What also helps considerably is that the air suspension in the back keeps the rear flat. A stiffer chassis (with the battery acting as a stressed member) and lower centre of gravity (by 53mm) than a 3 Series make the i4 feel positively sporty.

Light steering apart, the i4 is so good to drive, it’s eye opening.

Far from driving like a boring electric (there are enough of those around), it turns into corners with the nimbleness of an athlete. It changes direction beautifully, remains poised and well balanced in corners and then, even as I go faster, the i4 still manages to convey plenty of confidence. Still, I would certainly have liked more connect and weight from the steering, especially in Sport.

Steering apart, what gets my smile out is just how linear the build up of cornering forces are. How, as I approach the limits of the tyres’ adhesion, the i4 transitions smoothly. No sudden dump of torque that overloads the rear tyres. It’s so much fun getting the rear to unstick, even if only marginally, that I soon forget I’m driving an electric. And then, what makes it feel even more compact is that all the mass is concentrated around the centre, so polar motion of inertia is low.

The i4's performance is quite impressive when compared to the M340i.

The i4 also has plenty of poke. Putting out the equivalent of 340hp between 8,000rpm and 14,000rpm, the electric-only i4 in Sport takes off like a scalded cat. Put your foot down and the speedometer just jumps up, a strong stream of silent powering you forward. What’s also nice is that unlike many electrics, the throttle is linear. Squeeze down more on the right pedal and you are presented with correspondingly more power, all delivered in a well-metered manner. It isn’t quite the same as on a combustion engine and, of course, responses flatten out after the midrange. Still, for an electric, the i4 is seriously impressive.

What you do have to be careful of, however, is the 125mm ground clearance. This is especially true over poorly constructed speed breakers, of which we have many. Although we managed to avoid grounding the battery over most speed humps by approaching them at an angle, managing this with a full load of passengers and luggage will be more difficult.

BMW i4 vs M340i: design, interior

Both the i4 and the M340i have their own unique attributes, allowing them to stand out.

What also makes the i4 feel significantly off the future is the design and build of both exterior and interior. BMW’s evolved kidney grille, as always, looks better with time. Still extremely in your face and attention-seeking, it no longer looks excessive or out of place to me.

The i4's massive grille takes some time getting used to.

In fact, if anything, I think it’s looking better and better. Also attractive is the tight-fitting coupe-like roof and the manner in which BMW has added pizazz to the rear. Particularly like the layering on the boot and the manner in which a sporty element has been added.

i4 tail-light is more evolved and modern.

The almost 15-inch curved panel on the inside also gives the cabin an airy and very modern feel. While the car is based on the 4 Series pillarless coupe, it still manages to have a modern vibe to it.

14.9-inch curved panel is a highlight of the i4's cabin.

The curved roof and low-set rear seat, however, mean comfort levels at the back aren’t as good as in a 3 Series. Still, it’s pretty practical; especially with its 83.9kWh battery and claimed 590km range. Expect around 350km in the real world, and a bit less if you have lead in your right foot.

The 340i is the more traditional of the two BMWs. A proper sedan with traditional doors and a proper boot, unlike the i4’s hatch, it is after all a 3 Series. The nose also conforms better to the traditional BMW kidney grille and double-barrel headlight set-up.

Traditional ‘L’ shaped tail-light on 340i.

The 3 Series also has extremely pleasing lines, and here, adding in some M or motorsport kit does it a world of good. Step inside and the cabin looks familiar. This is no surprise. What feels ancient, especially after the i4, is the small iDrive screen.

The cabin of the M340i looks quite dated when compared to the i4.

There’s no way you can compare this traditional screen with the panoramic one on the i4. But what the 340i has is more space and comfort at the rear. A lot more legroom, better back and thigh support (this car has no battery raising the floor) and more head and shoulder room as well.

More space and comfort in rear of the 340i.

BMW i4 vs M340i: performance

Getting behind the wheel after the i4 comes as a bit of a shock. The first thing that hits me, and really hits me, is just how much more feelsome the steering is. It’s just dripping with connect and feedback. There’s a lot more weight, loads more heft, and in corners, it loads up even more, conveying forces at work almost perfectly. It’s so good, in comparison to the i4, it’s absurd.

That said, the ride clearly isn’t as comfortable as on the i4. There’s a stiffness in the suspension that results in a busy and lumpy ride, especially over less than perfect stretches. There’s a lot of up and down movement, and over sharp bumps the 340i sometimes even thud-thuds through.

The M340i's ride isn't as comfortable when compared to the i4's.

The 340i also feels naturally agile. The junior M car set-up is specifically tuned to deliver the sportiest drive experience and this is evident ‘straight out of the box.’ The M Division has lowered the suspension over a regular 3 Series by 10mm and the set-up is a bit firmer. All this pays dividends as you carry speed into a corner. The nose stays flat, the body control is nice and tight, and as soon as you get to the apex of a corner, what makes this car so fun is that it goads you into getting on the throttle nice and early.

The xDrive all-wheel drive system on the M340i encourages sporty driving.

Get into a flow, learn to feed in just the right amount of power at the right time, and the 340i makes for a seriously entertaining drive. It doesn’t quite have the traditional rear-biased feel of a 3 Series or an M3, due to the xDrive or four-wheel-drive system, and that means there’s scope for improvement. However, putting the car in Sport or Sport+ does send more power to the rear, which does prevent it from feeling like it wants to run on straight as you apply power on exit. Still, it will understeer at the limit, rather than rotate gently around its centre. And this limits driving pleasure. Job for the facelift: swap adjustable dampers for the four-wheel-drive system.

The truly outstanding bit on this car, however, is the engine. Smooth, creamy, explosive in its power delivery and seriously potent, this straight-six is exceptional. The four-wheel-drive system puts down power so effectively, 0-100 comes up in just 4.4sec, bang into sportscar category. What’s even more fun is mashing your foot down from say 50 or 60kph. The lightning-quick 8-speed ZF gearbox drops the engine right into the most explosive part of the powerband, the tachometer flies up the dial and you are catapulted forward on an ever-increasing band of torque and power.

It’s no longer about only power, but how the car makes it, and how it makes you feel.

While responses on the electric i40 are more instant, power soon plateaus and tapers off. It’s the reverse here, as the 340i’s straight-six delivers more and more power as you climb the powerband. And, just as you approach the limit, it’s bang into the next gear and the meat of the powerband again, as you wind up to the redline, the engine spinning free like a big turbine. Wow, what a ride. 387hp? It feels like there’s more here.

BMW i4 vs M340i: verdict

That BMW has come so far with the i4 is something of a mini miracle. Remember, this is its first all-electric sedan and, in a nutshell, it’s just fantastic to drive. It’s got a beautiful chassis, it points into corners nicely, the throttle is nice and linear and it gives you that sporty feel we all look forward to in a driver’s car. It’s so much more than just an electric.

The M340i, however, is clearly the better driver’s car. The turbocharged straight-six engine is easily the best bit. Turbine like smoothness, explosive performance, a willingness to just rev and rev; this is as good a turbocharged petrol as you are likely to find anywhere.

And that sporty exhaust just sounds great. Then the steering is bursting with feel, the chassis is super agile and it turns into corners so sweetly, it goads you into going faster and faster. The xDrive or four-wheel-drive system means it isn’t quite as nicely balanced at the limit, and the ride is a bit hard. Still, if you are looking for driving pleasure, this is it.

Sure, the i4 is fantastic to drive, probably more entertaining from behind the wheel than a Tesla Model 3. And one day in the future, it could even deliver a better driving experience than a junior M car like the 340i. But not today. For now, the 340i still rules. And who knows when you’ll get another chance to buy a 3 Series with a straight-six? Probably never. Time to smash that piggy bank.

Also read:

2022 BMW i4 vs M340i comparison video

BMW i4 review: Will lure you away from petrol, diesel luxury sedans