Audi S5 vs BMW Alpina B4

What's the difference?

The Audi A5 remains a convincing option in the premium mid-size sedan category, even with the near-$10K price increase over its equivalent grade A4 predecessor.

Even in its base spec, it’s a lovely thing to drive and adds enough new kit to be a reasonable option when it comes to value. In terms of tech usability, it stands out from rivals. Practicality is still king for Audi.

But for the heart-over-head types, the S5 is fast and fun while remaining a comfortable cruiser and the price is decent. On a personal note, a six-cylinder wagon? That's a big yes from me.

For the time it’s available, it’s hard to go past the value on offer in the S5 Edition One. Getting an AWD V6 with that kind of capability for under $100K is something that's sure to tempt buyers. If it doesn’t, we need to take a good look at ourselves.

Note: CarsGuide attended this event as a guest of the manufacturer, with meals provided.

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.

The A5 incorporates Audi’s new design language in a way that makes the 2026 model stand out from Audi’s older offerings, but we won’t know how well it works in the family until more new-gen Audi cars arrive.

For now, the A5 is a generally handsome car. It very much looks like an Audi from the front, even a recent A4 if you only very quickly glanced.

The aforementioned S line styling does plenty in making even the base Audi A5 look like a properly luxe thing. There were a few double-checks at the launch to make sure drivers were getting into the right cars.

Fortunately the new car’s designers refrained from busying up the car with trim, the only big features being the side vents at the front.

But even in Avant form the S5 looks athletic, quad-exhausts in the lower bar and the angular rear bodywork moving away from the previously softer, more rounded look Audi had gone with before.

Inside, the changes are arguably more obvious. The A5 is now much more ‘screeny’ than before, especially if optioned with the passenger-side touchscreen.

It’s still decidedly Audi in its layout and design, with geometric shapes on the steering wheel, screen housing, door cards and even on the gear shifter, which is no longer the more traditional handle-type.

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.

…and that gear selector is a bit indicative of the new A5’s interior. It’s now more of a switch that requires a little more attention than the traditional shifter, just like the way the more screen-focused interior requires a little more of your eyeball time than physical buttons.

Don’t get me wrong, as far as screens in modern cars go, Audi seems to have made it as easy as possible to use the new-gen software in the A5. The menus are clear, there are good shortcuts and there’s no lag… but buttons are always better when your focus needs to be on the road.

Fortunately the driver display is nice and clear, it’s a good update on Audi’s ‘Virtual Cockpit’ and you can set it to display important information without looking too busy.

Ergonomically, the way the central screen is angled towards the driver, the centre console layout and the small control panel on the door for lights, mirrors and the like all seem to be well considered and mean you don’t have to awkwardly reach for anything.

There are a few quirks specific to the A5 and S5, one being that if you opt for the panoramic sunroof, it comes with a transparency switch rather than a physical cover, so it doesn’t do much to keep the light out.

It’s also good to note that the passenger screen - again, if optioned - turns to privacy mode when playing media so as to not distract the driver. Pretty handy!

Behind the front row, a regular-sized adult should have enough room to sit comfortably for a decent amount of time without feeling cramped. The light through the sunroof comes in handy here.

Behind that is a 445L boot in Sedan form, or 1299L with the rear seats folded down. As an Avant, the space increases to 448L and 1396L respectively.

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.

The Audi A5 is powered by a four-cylinder turbo-petrol engine which powers the front wheels via a seven-speed dual-clutch automatic transmission. It makes 150kW of power and 340Nm of torque, and should, Audi says, propel the A5 to 100km/h in 7.8 seconds before (eventually) reaching a top speed of 248km/h.

The S5, in all its variants, is powered by a 3.0-litre turbo-petrol V6 which is assisted by a mild hybrid system. It produces 270kW and 550Nm, sending that to all four wheels via a similar seven-speed dual-clutch.

The S5 is much quicker as a result - 100km/h comes along in just 4.5 seconds according to Audi, before reaching a 250km/h top speed.

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.

Audi claims the A5 uses 6.9 litres of fuel per 100km, which should theoretically deplete the 56-litre fuel tank after 811km of driving. We couldn’t test this on the launch, but reaching claimed fuel efficiency figures remains an elusive challenge.

The S5, according to Audi, comes with an impressive 7.1L/100km figure in Sedan form, or 7.2L/100km as an Avant. That’s 788km and 777km of theoretical driving range if you’re up for a challenge.

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.

One of the first press cars I ever drove as an even younger lad than I am now was the circa-2017 Audi S4.

Without the perspective of all the many, many cars I've since driven, that S4 blew my mind a little bit with its combination of capability and refinement.

Now, with the context of most of the cars available to the Australian buyer in mind, it’s reassuring to get into this new generation and find that the mid-size Audi torch has been gracefully passed on.

Audi says the new generation, sitting on its new platform, has more focus on balanced driving dynamics, steering precision and steering feel. Without sacrificing comfort, Audi wants the A5 to be a sharper driver’s car.

It might not gel with the Euro tradition of a rear-drive executive sedan given the base A5 is front-wheel drive - the brand of course focusing on its quattro all-wheel drive system - but the A5 is decidedly agile for its size. 

Compared to the S5 especially, as the A5’S 1770kg plays the S5’s 2025kg in Sedan form (2040kg as an Avant). It’s a noticeable weight difference, and it makes the A5 more playful without getting properly ragged.

It also rides on smaller 19-inch wheels and would overall probably make for the better daily driver. Even without the all-wheel-drive traction and extra power the S5 offers, the A5 makes a good case for properly plush commuting. Its 150kW isn’t lacking by any means, and that 340Nm does plenty to help when overtaking.

Its suspension feels well damped, keeping the road’s imperfections out of the cabin without numbing the ride and leaving you without feedback. The steering is similarly direct without being too heavy, making the A5 feel athletic for its size.

But for all the A5’s strengths, there is something undeniable about a six-cylinder European sedan (or wagon). The S5 is heavier, sure, and therefore not as naturally nimble, but it makes up for it. And it’s not just the extra power and mild-hybrid assistance.

It’s a great highway cruiser for a start, but it also adds the confidence of all-wheel drive to a trip, which proved extremely useful on the very rainy winter day we tested it. It holds up well on rough surfaces despite the bigger wheels and extra heft, plus it doesn’t feel out of hand when cornering fast, rolling into a predictable understeer rather than quickly losing traction.

But if you’re in any way conscious of your budget, consider the Edition One. It doesn’t lack any of the key things that make the S5 great, and you get to pocket enough money to buy a second used car.

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.

Audi’s five-year/unlimited kilometre warranty is starting to fall behind the industry standard, though is about normal for a premium brand. On top of this, customers can opt to purchase extra years of warranty up to a maximum nine years which costs $3590.

Audi does also offer 12 years of bodywork manufacturing warranty against corrosion or perforation. There’s also five years of Audi roadside assistance.

Servicing intervals for the A5 come in at every 15,000km or 12 months, with customers able to purchase fixed-price servicing plans at a discount compared to paying per service.

A five-year servicing pack for the A5 Sedan is $3360, and for the S5 it’s priced at $3540.

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.