Even for someone who has been doing this for a while, discovering you’re not quite so damn clever as you thought happens more often than you might imagine. You drive three cars weeks, months, perhaps years apart, and because you have figured out what you think about each, you reckon you could make a fair approximation of what they’re like relative to each other. It’s a mistake that’s all too easy to make. Take the following example.
We were so excited about the prospect of finally being able to do this test, it only becoming possible after BMW finally gave up its hitherto steadfast refusal to marry M3 running gear to Touring bodywork. BMW M3 versus Alpina B3 versus BMW M340i, all in Touring form? Well it was a prospect too delicious to pass by. But even as we gathered in a quiet corner of Wiltshire their roles already seemed cast: the M3 the rocketship, the B3 the executive express, the M340i the plucky compromise for those who can’t quite afford the small BMW estate they really want. Thing is, it didn’t quite turn out like that.
Given they all got built in the same factory and on the same platform, given all have 3.0-litre, straight-six turbo motors, eight-speed ZF automatic transmissions and all have four-wheel drive, there are some intriguing differences in their specifications.
For example, one of them has a different engine to the other two. Different capacity, different bore, stroke and turbocharging philosophy. It is the M340i. Why BMW should feel the need to have two such motors with just a 5cc capacity difference in production would have puzzled my Economics teacher, but there you go: the M3 and B3 have the twin-turbo 2993cc S58 engine, the M340i the related 2998cc B58 unit.
Both are undersquare – which is to say the length of their strokes exceeds the width of their bores – which should promote torque at the expense of power, but the M340i engine is considerably more so. Note too that it has a single twin-scroll turbo, compared to the two individual puffers worn by its brethren. I expected it to have a higher compression ratio, which it can get away with thanks to the comparatively modest level of boost being blown through it, but its 10.2:1 stands in considerable contrast to the 9.3:1 of the M3 and B3.
In terms of power, the 374hp offered by the M340i seems impressive only until you realise it’s over 100hp shy of even the 495hp B3, let alone the 510hp offered by the M3. But there’s another thing: I have to say I thought the power gap between M3 and B3 would be greater. This is because Alpina always tunes its motors for torque, preferring to provide the urge in the mid-range where it is more readily accessed and used, and here the difference is far greater: 538lb ft of the stuff down at 2,500rpm for the Alpina, ‘just’ 479lb ft for the M3, at a slightly higher 2,750rpm. The M340i has only 368lb ft to cover its embarrassment, but perhaps as a small clue to what’s coming, it’s all there, right down at 1,900rpm, barely double its idling speed.
It has another advantage too. I’ve heard the M340i called the ‘diet M3’ and it was not intended as a compliment; it’s the not quite M3, the M3 Junior, the M3 Lite. Well they got that last bit right: it might sound heavy at 1,770kg – how did compact cars like this get to weigh so much? – but it’s almost 100kg lighter than the M3 which itself is 15kg lighter than the B3. Put me in either of them and you’re getting worryingly close to a two-tonne 3 Series.
Go from one to the next and you cannot escape the sense of the same car dressed up for different occasions. Smart casual for the M340i, business attire for the B3, party shirt for the M3. Given how much they have in common, the difference in the visual statements they make is striking. I like all three but was in a minority of one among those assembled in liking the M3 least. With the grille, the fake bonnet vents, the side strakes, swollen arches and almost certainly non-functional beefed-up rear diffuser, it looks muscled, somewhat steroidal indeed. I don’t want a car that draws attention to me, let alone makes a statement like this.
I much prefer the B3 approach, though I’d lose the decals. The turbine wheels are part of Alpina heritage, a nod to those who know, but other than its extended chin spoiler, it’s really pretty sober. It tells you what it is without trying to ram it down your throat. The M340i? In an era when BMW can’t launch a car without an accompanying barrage of abuse about its styling, I think it’s nicely done, especially in the matt grey paint it shares on this occasion with the M3.
Inside you notice what they share far more than what sets them apart. All three have the same basic interior, differentiated by limited use of different materials in certain places, the B3 having, for example, the best steering wheel leather I can remember. All three have option seats, the B3 and M340i the ‘Comfort Plus’ chairs, the M3 the sports items with the rock hard centres beloved of the young and agile, bemoaned by the stiff and middle-aged.
But I don’t really see why three different gear shifters are required. The M340i doesn’t even get a proper lever, just a large switch you push forward and backwards. It works well enough and is swifter in action when turning around in tight spaces, but comes with no sense of occasion at all. The B3 uses the conventional stick which you nudge across into a second plane for those who want to change manually, but not use the paddles. But do the same in the M3 – as I did out of habit more than once – and you find yourself revving away impotently in neutral. Of the three systems the Alpina’s works best.
Otherwise the Alpina comes with its own typeface and rather restful blue tinge on the instrument pack, while the M3’s main information unit allows a degree of configurability of which the other two can only dream: three settings for the engine and chassis, two for the steering and brakes plus, of course, the option to disconnect the front driveshafts and drift around in rear-drive only. I suspect it’s a feature owners spend more time pointing out to their mates than actually using, but it does no harm and shows that BMW’s M department has not entirely forgotten its once exclusively correct-wheel drive roots.
A benchmarking exercise is needed, so it’s the M340i that I turn to first. If I need to declare an interest here, it’s that – as regulars will know – this car has been living with me for the last six months and I’ve put nearly 15,000 miles under its wheels, including driving it to Bosnia and back. It is a fantastically easy car to live with, possessing strong performance when it’s needed, peace, quiet and surprisingly good fuel consumption when it’s not.
But perhaps what I enjoy most about it is that its engine and chassis feel perfectly matched. As you can see from the figures, the performance is more hot than scalding, but so wide is its torque band and so immediate its throttle response, the car feel scarcely turbocharged at all, and can pile enough torque into its Bridgestones to keep them as busy as they would like to be. The steering is precise without being sharp, and the car’s natural balance sufficient for you to neatly trim your lines with your right foot, meaning it always ends up where you want it to be.
Even so, this is not a ten-tenths car. It likes being close to rather than right on the limit, let alone over it. There is limited enthusiasm for that kind of behaviour which given how rarely it will be subject to it, is probably fair enough.
The B3 feels instantly different, not just to its stablemates, but any other BMW. Despite its big wheels and skinny sidewalls, there’s a languid quality to its ride that, among cars with propellers on their noses, could only come from Alpina. The way it controls roll in a gentle, linear movement is just delightful, providing the ride with an insouciant quality that borders on the uncanny. It is instantly and always special, lending the car a character entirely distinct from those developed exclusively by BMW.
My feelings about its engine are more mixed. The good news is that its power deficit to the M3 motor is essentially an irrelevance because it’s more than offset by its additional mid-range torque. No question that, in a straight line at least, it feels the quicker car. And I had not expected that. But if the idea of loads of low-down torque seems like a no-brainer as an idea, in reality there is a considerable pause between the request leaving your right foot and it being answered by the engine. It is a form of old-fashioned turbo lag, and with its two little turbos, I’d not expected that either.
There is no doubting the punch when it comes and the sophisticated, satisfying howl from the engine is entirely in keeping with Alpina values. It’s just a little slower out of the blocks than it should be. Nor is this really a car for hoofing around on the limit. There’s plenty of grip from its bespoke-developed Pirellis but there’s a small price to pay in ultimate body control for its fabulous ride quality which I am sure almost all owners will either not notice or be happy to accept, but this a more touring than sports oriented car and, given it’s also a five-door estate, there’s plenty of common sense in that.
The M3, however, begs to differ. You know it from its looks, its configurability and the sound of its engine. I’d bet plenty of its internals are either identical or scarcely changed from those of the B3 but it sounds like a different motor entirely: deeper, more raw, urgent and, absolutely, more exciting too. It just goes to show what can be achieved when the sound engineers get involved.
It's more a surprise than a disappointment that the B3 is quicker and, to be honest, I’d happily give up that advantage if it gave me my throttle response back. Which is precisely the trade the M3 makes. It may not go quite so hard low down, but it goes a lot sooner and carries on for longer. In both feel and response it is a significantly more sporting power unit and similarly suited to the character of the car.
But it’s chassis set-up where the difference is really felt. BMW’s approach is the reverse of Alpina’s: for a car of such heft, its movements are phenomenally well controlled. It gives you a greater feel for the road meaning its sharper turn-in is not in the least unsettling. Mid-corner there is no trace of float or wallow and you can use that superb response to your right foot to always ensure you dose the tyres with no more or less torque than you want. Given it’s an estate and a weighty one at that, it is a remarkable performance.
And if it did not come at a price there’d be little more to say here. But you cannot tie down a car of this weight so securely on its springs without consequences and largely it is you who has to bear them. The secondary ride – the lumps and bumps – are actually absorbed far better than I had expected, but the way your head and body are abruptly moved left and right with each undulation of the road and in every corner is far less welcome. I found it tiring and, ultimately, tiresome too. There’s a clear case for an uncompromising set-up in an M4 coupé. But an M3 Touring? It is simply too much.
Is it enough to deny it victory here? I’m afraid so. I do really like this car and as a driving machine it is clearly the pick of the three, but the opportunity to enjoy what it can do and the others cannot are rare, while the compromises that result are experienced on each and every journey.
There’s a very large part of me that wants to give this to the M340i; indeed were we awarding moral victories, it would grab it with both hands. It is a million miles from being the poor relation here, and gets closer to its more vaunted relatives than the price disparity between them would ever suggest. My long-held view that this is the best car BMW makes remains intact.
But only because Alpina takes M340is and turns them into B3s. It’s not just that it feels so different to the BMWs, nor that its feel is so characteristically Alpina. The fact is that for almost all of almost every journey it just works the best. Of course ideally you’d have the engine of the M3 in the chassis of the B3 at the price of the M340i, but that’s not the way the world works.
The Alpina’s margin of victory may be small, but so too is it clear. That small band of miracle workers from Buchloe in Bavaria have done it again.
SPECIFICATION | Alpina B3
Engine: 2993cc, 6 cyls, twin turbochargers
Transmission: 8-speed automatic, four-wheel drive
Power: 495hp at 5000rpm
Torque: 538lb ft at 2500rpm
0-62mph: 3.7 secs
Top speed: 188mph
Weight: 1880kg (DIN)
CO2: 229g/km
MPG: 28
Price: £80,700
2020 Alpina B3 | PH Review
SPECIFICATION | BMW M340i Touring
Engine: 2998cc, 6 cyls, single twin scroll turbocharger
Transmission: 8-speed automatic, four-wheel drive
Power: 374hp at 5500-6500rpm
Torque: 368lb ft at 1900-5000rpm
0-62mph: 4.5 secs
Top speed: 155mph (limited)
Weight: 1770kg (DIN)
Economy: 36.2mpg
CO2: 177g/km
Price: £60,700
2023 BMW M340i xDrive | PH Review
SPECIFICATION | BMW M3 Touring
Engine: 2993cc, 6 cyls, twin turbochargers
Transmission: 8-speed automatic, four-wheel drive
Power: 510hp at 6250rpm
Torque: 479lb ft at 2750rpm
0-62mph: 3.6 secs
Top speed: 155mph (limited)
Weight: 1865kg
MPG: 28-28.2
CO2: 230-227g/km
Price: £86,570
2023 BMW M3 Touring (G81) | PH Review
Photo credit: Mark Riccioni
This comparison test originally featured on The Intercooler. Ti is the original ad-free online car magazine and is active across a wide range of platforms: subscribers get unlimited access to our content, including new episodes of our hugely popular podcast and we produce interview-based podcasts exclusively for subscribers. You can also follow us on social media and subscribe to our YouTube channel.
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