Mercedes-Benz CLS-Class vs BMW Alpina B4

What's the difference?

Comfortable when it needs to be and sporty when you want it to be, the CLS 53 is a bit like Mercedes’ Doctor Jekyll and Mr Hyde – or maybe Bruce Banner and the Hulk is a better frame of reference for some.

While it doesn’t excel in any one particular area, its breadth of useability is commendable, but ultimately it might be its all-too-familiar aesthetics that is the biggest letdown.

From the inside, it looks and feels like any other large Mercedes model (not necessarily a criticism), while the exterior – in my opinion – doesn’t go far enough to differentiate it from the CLA.

After all, if you wanted a stylish and sporty sedan, shouldn’t feel special too?

You could almost call the B4 S the anti-M4. It's still fast and practical but from a completely different perspective. It's much more a grand tourer than the M4 and even with the Akrapovic exhaust (usually a byword for joyous, anti-social racket), subtle.

For some, the price won't matter because the Alpina delivers what they want - M4-like straight line performance without the histrionics or the uncompromising chassis. And there's also a bit of that perverse exclusivity of the styling that you won't get anywhere else.

Mercedes’ homogenised design is a bit of a double-edged sword, and while the CLS does wear its styling confidently, it probably looks a little too much like the cheaper and much smaller CLA for our tastes.

Both are swoopy four-door coupes from Mercedes-Benz, so of course there will be some similarities, but keen-eyed car spotters will notice some differences.

While the proportions are similar, the longer wheelbase and bonnet line gives the CLS a more mature look, and the extra details found in the head- and tail-lights, and front bumper stand it apart.

The changes to the 2022 version also brings in AMG’s 'Panamericana' front grille, which adds a bit of welcome aggression to the front end.

From the side, the steeply raked roof flows seamlessly into the rear, while the 20-inch wheels fill out the arches well.

All four doors are also frameless, which is always cool to see.

From the rear, quad-exhaust tips hint at the CLS’s sporty intentions, while a prominent rear diffuser and subtle boot lid spoiler also feature.

Inside, the biggest change to the CLS is now the inclusion of the MBUX multimedia system, which keeps it in line with the E-Class, C-Class and other Mercedes models.

AMG sports seats are also fitted, wrapped in Nappa leather and 'Dinamica' fabric upholstery for all pews.

Our test car also came fitted with red contrast stitching and seat belts, adding a racy streak to the CLS cabin.

Have to point out the new steering wheel that comes with the 2022 CLS, though, which mirrors the tiller offered in the new E-Class, and is a step back in terms of functionality.

It looks premium enough thanks to its chunky leather-wrapped rim and gloss black dual-spoke design, but using the buttons, especially when on the move, is difficult and unergonomic.

This design is definitely function over form, and might need a few more revisions to get it right.

Overall, we’d say the CLS is a good-looking car, but does play it a bit too safe with its styling?

Alpina has always had a particular aesthetic that could uncharitably be termed as mid-'80s West German - all set square angles and body graphics. Think David Hasselhoff's Berlin Wall look. The company has never really deviated from adding squared-off body bits to the various BMWs it has rebadged under its long-running agreement.

For the B4S, Alpina adds the signature billion-spoke alloy wheels (only a slight exaggeration), a new front splitter complete with Alpina lettering, a weirdly proportioned boot lid lip spoiler and - not even joking - pinstripes. Like I said, mid-'80s West German. You can still recognise the sleek 4 Series Coupe but perhaps the worst of it is the super-sized, wonky-looking ALPINA B4S on the boot.

Inside is rather more restrained apart from the ill-fitting Alpina plaque under the climate control. Again, it's all 4 Series in here, with the lovely Merino leather liberally applied across the cabin. Less lovely is the wood on the door pulls and console but the door cards have an oddly appealing woven leather which looks and feels good.

Sadly the standard 4 Series steering wheel is along for the ride. There's nothing wrong with it - although the Alpina logo does look out of place - but if I were a product planner, I'd beg for the lovelier M wheel.

Measuring 4994mm long, 1896mm wide, 1425mm tall and with a 2939mm wheelbase, the CLS slots neatly between the E-Class and S-Class in size and positioning.

Up front, occupants are afforded ample room for head, legs and shoulders, while the electronically adjustable seats make it easy to find a comfortable position.

The steering wheel also features a telescoping function – an always appreciated feature – and the expansive glasshouse makes things feel open and airy.

Storage options include a deep door pocket, a cubby found under the armrest, two cupholders and a smartphone tray with wireless charging capabilities.

It’s a different story in the second row, though, as the sloping roofline does noticeably eat away at headroom.

Don’t get me wrong, a six-foot-tall (183cm) adult can still slide in there fine, but the roof is dangerously close to the touching the top of the head.

Leg- and shoulder-room is pretty good in the outboard seats though, while the middle position is compromised by the intrusive transmission tunnel.

In the second row, passengers have access to a bottle holder in the door, a fold-down armrest with cupholders, backseat map pockets and two air vents.

Opening the boot reveals a cavity offering 490 litres of volume, with an aperture wide enough to fit golf clubs or luggage for a weekend getaway for four adults.

The rear seats also fold in a 40/20/40 split fashion, but Mercedes-Benz is yet to detail how much volume is on offer with the rear seats down. And as a traditional sedan, the CLS is less practical than the liftback Audi S7.

If you're in the front, you're in luck - it's a comfortable place to be, with plenty of leg and headroom. Down back isn't terrible despite the coupe roofline. The two seats are nicely shaped for maximum comfort and separated by an odd plastic tray. The fold-down armrest has two cupholders.

Front seat passengers score a pair of cupholders (bring the total to four for the car) and the long doors will hold a bottle each.

The boot swallows a reasonable 445 litres, which isn't at all bad.

If you thought BMW don't mess about when pricing up its cars, you best strap yourself in. The 440i-based B4S starts at a solid $149,900. That's $48,000 more than the 440i and significantly more than an M4 Pure. But there's plenty of gear on offer and some genuine, bespoke Alpina additions.

Standard are 20-inch signature Alpina alloys, 16-speaker harmon kardon-branded stereo with DAB, super-soft Merino leather everywhere, dual-zone climate control, around-view cameras, reversing camera, sat nav, keyless entry and start, front and rear parking sensors, active cruise control, heated and electric front seats, head-up display, auto headlights and active LED headlights, LED taillights and electric sunroof.

The stereo and sat nav are run by BMW's iDrive. It's a cracker of a system and almost gets away without Apple CarPlay and Android Auto. The absence of such simple pleasures at this price point is a bit lame, but here we are.

Powering the Mercedes-AMG CLS 53 is a 3.0-litre turbocharged inline six-cylinder engine, punching out 320kW/520Nm to all four wheels via a nine-speed automatic transmission and Merc's '4Matic+' AWD system.

A 48-volt mild-hybrid system, known as 'EQ Boost', is also fitted that serves up to 16kW/250Nm from take-off.

The result is a 0-100km/h acceleration time of 4.5 seconds, keeping it on pace with the likes of the 331kW/600Nm Audi S7 (4.6s) and 390kW/750Nm 250kW/500Nm BMW 840i Gran Coupe (5.2s).

While not as brutish as AMG’s eight-cylinder engine, the straight six strikes a great balance between pace and poise that perfectly suits a model like the CLS 53.

A lot of your extra money turns up under the bonnet. These days the 440i packs BMW's slick B58 turbo straight six and the B4S does likewise. The boys from Buchloe in Bavaria (there are certain to be women there, too, I just liked the alliteration) added a pair of Alpina-spec turbos to generate a whopping 324kW and, more importantly, 660Nm. Alpina says 600Nm (the max torque figure of the brilliant M4 CS) is available from 2000-5000rpm, while the full 660Nm is available from 3000 to 4500rpm.

The M4 Pure has 317kW and 550Nm from the S55 straight-six. Just so you know.

Like the 440i but unlike the M4, the B4S employs the dependably brilliant eight-speed ZF automatic found throughout the BMW range.

Official fuel consumption numbers for the CLS 53 are pegged at 9.2 litres per 100km, while we managed an average of 12.0L/100km in our launch drive.

All of our driving was relegated to country back roads and high-trafficked urban areas however, with no consistent freeway driving.

We’ll reserve judgement on how accurate the fuel economy figures are until after we’ve had the car for longer, but the EQ Boost system is designed to help keep consumption down by being able to coast the engine in particular situations.

Alpina quotes 7.9L/100km on the combined cycle and we went through the premium unleaded at the rate of 11.7L/100km. I enjoyed myself, so that's not a terrible result.

There are certain expectations on a vehicle when it wears a Mercedes badge, namely it should be comfortable to drive while also dripping with the latest tech. And here the large four-door coupe delivers in spades.

Driving the car is smooth, easy and comfortable when in its default drive setting, you can really sink into the CLS and just eat up the miles in comfort.

There are small niggles, like the 20-inch wheels and low-profile tyres (245/35 front and 275/30 rear) throw up a bit too much road noise into the cabin, but for the most part, around town, the CLS is serene, supple and supremely soothing.

However, switch it over to Sport or Sport+ and the steering gets a bit heavier, the throttle response a bit sharper, and the suspension a bit stiffer.

Does it transform the CLS into a sports car? Not quite, but it certainly dials up driving engagement to a level where you can really have some fun.

Though this isn’t a full-fat AMG in the same vein as an E63 S and doesn’t feature the ubiquitous 4.0-litre twin-turbo V8, the CLS 53’s 3.0-litre six-cylinder engine is still plenty potent.

Coming away off the line feels particularly brisk, likely due to the EQ Boost system adding a bit of poke, and even flat-footing it mid-corner delivers a noticeable surge of urgency from the creamy straight six.

However, the best of the CLS 53 experience, in my opinion, is actually the sound, with the exhaust letting off the right sort of pops and crackles in Sport+ mode on overrun.

It’s rude and obnoxious, but also completely surprising coming from the motoring equivalent of a three-piece dress suit – and I love it!

The brakes are also up to task for scrubbing speed, but our relatively brief time with the car was in extremely wet conditions, so the 4Matic+ AWD system was hugely appreciated.

One of the key differences between the B4 and M4 is the ride. While the M4 can crash over bumps and generally be a little hard to live with, the crew in Buchloe have gone after a much more plush ride. And in that they have succeeded because the B4 S is a mighty fine cruiser. Bumps are dismissed with a haughty disdain, even Sport + silliness doesn't completely write-off ride quality.

Very impressive too, is the steering. While still not at Lotus Elise levels of feel (few cars are), the Alpina tweaks connect the your palms to the road with more clarity than what you'll find in the 440i or M4. Where the M4 particularly adds too much weight, the 440i is a bit more circumspect in that regard.

And then we come to the engine. The B58 six is a belter, better even than the N55 that preceded it. It's still a 3.0-litre straight six but is part of BMW's modular engine family that starts with a 1.5-litre triple in the Mini and 1 Series. The Alpina-spec turbos are noisier, the Akrapovic exhaust lighter and also noisier. It doesn't have the all-out crackle and pop of an Audi or Merc (perish the thought), but when you're on it, the B4 means business. The 660Nm of torque, available over a wide rev range, delivers a steel fist wrapped in a velvet glove and bubble wrap - the speed builds rapidly but smoothly. 

The approach to the chassis tune seems to be based on the driving talents of mere mortals on normal roads, which is kind of like the 440i. It's terrific fun to drive hard but it's very forgiving and patient. The great thing about it is that you wouldn't think twice about jumping in it for the long haul, so comfortable and quiet is the cabin. The M4 will leave it for dead on a winding road, but that's perfectly fine.

One irritant is the replacement of the admittedly cheap BMW gearshift paddles with weirdly non-tactile buttons. They're not particularly easy to use and, probably worse for a sporty car, unsatisfying. It's an odd detail with which to go off the reservation. Cheeringly, the eight-speed ZF is its usual perfect self, so you don't have to worry too much about manual mode or go old school and use the shifter.

The Alpina ships with six airbags, ABS, stability and traction controls, ABS, stability and traction controls, forward collision warning, forward AEB, road sign recognition and active cruise control.

There are also two ISOFIX points in the rear. Neither the Alpina nor the 4 Series has an ANCAP safety rating.

Like all new Mercedes-Benz models sold in 2021, the CLS 53 comes with a five-year/unlimited kilometre warranty with roadside assist over that period.

This outclasses the assurance period offered by BMW, Porsche and Audi (three-year/unlimited kilometre), and matches that available from Jaguar, Genesis and Lexus, who recently upgraded their offering.

Scheduled service intervals are every 12 months or 25,000km, whichever occurs first.

The first three planned services will set buyers back $3150, broken down as $700, $1100 and $1350 apiece.

Alpina offers a two-year/unlimited-kilometre warranty which is a bit behind the times and not in keeping with the price point. Servicing is another matter altogether and you're subject to your dealer's standard charges for servicing.