BMW Alpina B5 vs Audi RS4

What's the difference?

The Alpina B5 is a special car – more special than most people will ever give you credit for if you own one. Those that do know what an Alpina is will let you know; people will cross dangerously busy streets to talk to you about your car. Insanely fast, almost incomprehensibly comfortable and effortlessly powerful to drive.

What a way to send off this generation of Audi RS4 and RS5. The extra focus courtesy of those trick coil overs and drama from the exhaust plus the sharper gear changes deliver the best Audi has done with these RS products. 

There are some compromises, with the suspension favouring outright control over low-speed comfort. It’s also true that the current BMW’s M3 and M4 are more impressive, but when the products are nearly seven years fresher than Audi’s, what do you expect? 

Plus, those looking for a more restrained and polite fast executive sedan (or wagon) will gel with the Audi’s sophistication. There aren’t many of these Competition Plus RS4 and RS5s coming to Australia and they are impressive visually and from behind the wheel. It’s a fitting way to send off the current generations.

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

Interesting is the right word for it, because while it might be questionable that Alpina's changes to the exterior are aesthetic pleasing, they are definitely intriguing to those who aren't familiar with the brand.

First, there are those 20-spoke wheels. Alpinas have worn this style of wheel forever and they've become the most famous outward sign that this is not just another BMW. So don't under any circumstances take them off and replace them with anything else. You'd be run out of town by the Alpina mafia.

Yes, they're more painful to clean than a cheese grater (trust me, I know. And if you look closely at these images you can see the dirty bits I've missed), but if you really don't like them then perhaps it's a sign this car isn't for you.

Then there's the boot-lid spoiler. It's square and 1980s'-looking, it also appears a bit like it's been bought online and installed by a teenager, but again, this is another Alpina tradition and it suits the car's character perfectly.

All right, those pinstripes; they're known as the Deco-Set and are a hat-tip to the Alpina racecars of the 1970s and '80s. Again, don't take these off, your Alpina will drop through the centre of the Earth in value. These are also part-and-parcel of owning one of these cars. I'm not a massive fan of them.

But I'm all about that front spoiler, with the floating Alpina lettering that you can option in silver, high-gloss black or gold.

Inside, there are fewer Alpina additions, but they're nonetheless unmissable. There's the Alpina-badged steering wheel, and a new virtual instrument cluster, embossed headrests and  illuminated door sills.

There's also the little numbered plaque on the centre console which proves its authenticity, ours was number 49. Out of how many? I don't know. But I do know Alpina produces only about 1700 cars globally a year. Rolls Royce does about 4000. So, you can rest assured your B5 is exclusive.

At almost 5m long, 1.9m wide and 1.5m tall, the B5 is a large saloon, but having recently reviewed the Alpina B7 it feels small in comparison. How does it drive? We're getting there.

The RS4 Avant’s 'Progressive Red' metallic helps the black milled 20-inch alloy wheels pop. Its stance is hugely purposeful with wheels tucked right up in the blistered arches courtesy of the lowered ride height — it's how the Avant would have looked in a design sketch.

The visual bulk of the long-roofed RS4 gives it the sort of proportions motoring journalists love to wax lyrical about, even if plenty of buyers still prefer coupes or lifted SUVs. 

The RS5's more flowing, elegant lines match well with the Navarra Blue paint work, silver-accented wheels and conventional leather-appointed seats within. 

Both cars have effectively identical front cabins reflecting Audi’s classy and sleek design language. The integration of technology is pretty good and the RS4’s additional red styling pack really makes it feel sporty within.

Practicality is not really a BMW strong point no matter which model you pick. See, BMW mostly makes the car equivalent of uber-stylish and skin-tight active wear which looks good and performs brilliantly, but sometimes you just want pockets and a bit of room for your… um… bits and pieces.

So while there are two cup holders up front and two in the back, the bottle holders in the doors aren't huge, the centre console bin is on the small side, there's a hidy-hole in front of the shifter, the glove box is just a box for little more than gloves and there's no other great cabin storage options.

Legroom in the rear is good but not great, too - I'm 191cm tall and have about 30mm between my knees and the seat back in my driving position. Middle-seat passengers will also have to straddle the drive shaft hump in the floor. Headroom is restricted in the back, too (you could blame the sunroof) with my hair just skimming the headlining (I do have big hair).

Under that power tailgate, the B5's boot capacity is 530 litres which is 15L more than its big sister, the B7. There are two plastic storage areas either side of the luggage space for wet things. While there is one USB outlet in the front there aren't any in the rear.

The RS4's cabin is excellent, with a good mix of physical buttons and responsive touchscreens for control. There’s enough storage space for this kind of vehicle, with good door bins and well-sized cupholders in the centre as well as USB-C and -A charge points. 

Audi’s multimedia system is friendly though the large touch targets and dark background aren’t as crisp as those fitted to the latest rivals. The screen isn't as big, either, measuring 10.1 inches for the multimedia item. The RS4 supports wireless Apple CarPlay and Android Auto.

That said, Audi’s 12.3-inch digital driver’s display with bright and poppy mapping software and generous customisation remains right at the head of the pack. 

There is a panel of switches below the touchscreen for climate control, physical selection of the five-or-so drive modes and a collection of helpful buttons on the perfectly-shaped and sized leather-appointed steering wheel.

It lacks F1 or DTM wow-factor compared to the C63 and M3 with their easy-access driver mode buttons and toggles on the steering wheel but the RS4's restrained looks will resonate with those that prefer a bit more elegance inside. 

Neither the RS4 nor RS5's back seats are designed for those over about 175cm. The RS4’s roof is a little higher so it is good enough for most adults but the RS5’s sloping profile compromises things. It has two individual buckets compared to the RS4’s three-wide bench. 

Rear seat passengers get air vents, an individual climate zone, bottle holders in the doors, USB charge points and ISOFIX attachments for the outboard seats, with matching top tethers in the seat backs.

The Audi RS4’s boot is a generous 505L with under floor storage and a netted area on the driver’s side. Folding the 40/20/40 split-fold bench increases space to 1495L. That said, the RS5’s 465L is still very good, though it is not quite as practical in the real world. 

Being fitted with roof rails makes for sleek integration of roof racks for the RS4 to slip roof pods, bike racks or whatever else you might choose to take on a trip away.

You'd expect the RS5 to be more popular given how uncool wagons are these days but Audi's whole thing is wagons — or Avants, for the initiated — so it makes sense that the RS4 Avant outsells the RS5 Sportback about two-to-one.

For the RS4 Avant’s basic asking price of $165,015, before on-road costs, you get luxury features such as LED headlights, an RS design package, Nappa leather upholstery, power-adjust seats, a Bang & Olufsen 19-speaker sound system and metallic paint on top of the significant changes to the RS4’s chassis and zingy 331kW V6. 

The RS5 is a little dearer, reflecting the addition of Matrix LED headlights that aren’t available on the wagon.

But we have the 'Competition Plus Pack', which is a $13,990 indulgence that swaps adaptive dampers for Audi’s 'RS Sport Suspension' coil over package with manual rebound and compression adjustment and height adjustment.

The cars sit 10mm lower than a normal RS4 but you can go to a dealer to move the ride height up or down from there. 

That’s not it, though. You also get a louder exhaust system with matte black pipes, fixed-ratio steering system, a retuned eight-speed automatic with more aggressive shifts, different rear differential programming, black exterior badging, 2.0kg lighter 20-inch Audi Sport wheels (in silver or black), special LED entrance lights and your speed limiter raised to 290km/h.

The 'Navarra Blue' RS5 pictured is a ‘basic’ Competition Plus. You can go further, as done with the RS4 Avant with its manual-adjust bucket seats ($1300), 'Interior Design Pack' in red ($3400), matte carbon exterior pack ($6300) and carbon trim, bringing its total cost to $191,405, before on-road costs. 

That makes the RS4 and RS5 the most affordable in their competitor set, below a BMW M3 Competition xDrive Touring ($183,500) and Mercedes-AMG C63 S E Performance hybrid, which is $187,900, before on-road costs.

The Alpina B5 uses the same 4.4-litre V8 engine found in the BMW M5 (and also the B7). But, and it's a big but, the M5 makes 441kW and 750Nm, while the B5 outdoes it with 447kW and 800Nm. Admittedly, the B5's torque arrives at the 3000rpm mark, while the M5's is all there from 1800rpm.

How does the B5 beat it? Alpina installed its specially developed twin turbochargers and intercoolers, a high-performance cooling system, a reconfigured air intake set up and a different exhaust system.

The B5, though, is a tenth of a second slower to 100km/h compared to the M5 with a time of 3.5 seconds, but it will blast on to a top speed of 330km/h while the M5 is limited to 250km/h in regular form and 305km/h with the optional M Driver's package.

Both uses the same ZF eight-speed automatic transmission with identical gear ratios, and both are all-wheel drive.

Audi’s 2.9-litre twin-turbo petrol V6 has seen plenty of use across performance products from Audi and Porsche, including the Macan S and Audi S6. 

In the RS4 and RS5 Competition Plus, it develops the same 331kW (at 5700-6700rpm) and 600Nm (at 1900-5000rpm) as the regular car. This makes it an extremely flexible engine that delivers predictable punch anywhere in the power band.

That said, it lacks the explosive character of BMW’s twin-turbo inline six — the figures are only 15kW and 50Nm higher on paper yet the M3’s response is that much more ferocious. 

Audi’s RS division has tried to capture a bit more emotion, retuning the eight-speed torque converter automatic transmission for crisper shifts. This also benefits the RS4’s 0-100km/h sprint time, which falls two tenths to 3.9 seconds in Competition Plus guise. 

The V6 breathes a little easier, too, with a different exhaust. Audi says the extra sound is down to 8.0kg less sound deadening in the car.

There’s more resonance at idle that does feel tiring sitting in traffic idling but the trade-off is a brawny mid-range baritone that develops into a shrill bark approaching the redline.

The Alpina B5 needs petrol. By that, I mean it needs quite a lot of it if you want to enjoy it properly. What type of mileage does it get? Officially, it should use 11.1L/100km after a combination of urban and open roads, where as the M5 is set to 10.5L/100km.

That makes sense, the B5 produces more power and torque, and it's 85kg heavier than the M5 at 2015kg.

Our test car's trip computer was reporting 13.2L/100km after flying low over country roads and slow city piloting. The more time spent in the urban warfare that is the daily peak hour commute, the more that figure crept and hovered around the 15L/100km mark.

The Audi RS4 wagon is rated to use 9.5L/100km in ADR combined cycle (urban/extra-urban) consumption testing while the slipperier RS5 returns 9.4L/100km in the same test. 

We weren’t able to run accurate or particularly relevant fuel figures on the event but the trip computers showed around 12L/100km in both RS4 and RS5. 

While these numbers are high compared to your average passenger car, the Audi is more efficient than BMW's rivals, and gets remarkably close to the hybrid C63 in the real world.

The fuel tank is quite small for this kind of vehicle at 58 litres. That limits the RS4’s theoretical driving range to 611km. 

Unsurprisingly, the Audi RS4 and RS5 require 98 RON premium unleaded petrol. 

Ok, stay with me here. For this next bit you'll need a fresh egg, a lounge chair, and it might be a good idea to have some plastic bags and carpet cleaner on hand.

First, in front of the lounge chair flatten out the plastic bag and place the egg on it. Next, sit down on the chair and very carefully rest the ball of your foot on the egg with as little pressure as humanly possible.

This is exactly how little force you need to apply to the go-pedal of the B5 to accelerate from a standstill to 60km/h in about five seconds.

If anything sums up the driving experience of the B5, it's that sense of effortlessness.

Stomp on that accelerator, and you'll be shot to 100km/h in 3.5 seconds, without a hint of broken traction thanks to the all-wheel-drive system.

The ride should have been terrible on 20-inch wheels shod in low-profile rubber (Pirelli P Zero 255/35 front, and 295/30 rear), but the Alpina-tuned air suspension is close to miraculous in the way it cushioned and censored the potholes out of Sydney's worst roads. Yes, it can be a touch floaty, particularly in the Comfort Plus setting, but this is benchmark-setting stuff for a comfortable ride.

Don't expect this beast to roar. Unlike the M5, the B5 gets its work done without deafening everybody around it. Sure, the B5's V8 sounds amazing when you push it, but it's not brash, not loud and not lairy. Buy an M5 or Mercedes-AMG E63s if you want to be heard half a block before you get home, but you won't get that with the B5 and its exhaust system.

The B5 also handles well, but I have to say the engagement factor is low. I piloted it effortlessly through the twists and turns of my country test circuit and roads which normally have me grinning like a maniac behind the wheel had me feeling a bit disconnected in the B5. That air suspension, the numb steering and pedal actions make it difficult to ‘feel' the road.

It's highways where the B5 is a king, but even at 110km/h there's the sense that this car is still fast asleep and won't get out of bed for anything less than 150km/h - making it perfect for Germany's autobahns, but maybe not for here in Australia.

The time allocated to driving the RS4 Avant Competition Plus was fairly limited and we were sadly unable to sample how the highly adjustable coil over suspension performed where it makes most sense — on the racetrack. 

Still, winding country roads between Sydney and the Southern Highlands served up some challenges, demonstrating how the Competition Plus pack changes the character of the RS4 and RS5. 

The only real negative is comfort, specifically over those horrible plastic speed bumps that litter shopping centre car parks. With adaptive dampers, carmakers can set programs for these kinds of obstacles to soften and stiffen the clever shocks at just the right time. Not so the Competition Plus pack cars, which ride these bumps harshly.

That about does it, though, and everything thing else is a net benefit. The steering system addresses some criticism of the earlier RS4s. Further than a retune, the Competition Plus gets a new rack, that is non-progressive with a fixed ratio of 15:1 (instead of 13.3:1) and 2.4 turns lock-to-lock. The reactions to each input feel a hint more faithful. 

When above 40km/h the coil overs come into their own. Even though the RS4 rides firmly it doesn’t constantly jiggle over small bumps. Over sharp-edged hits, the suspension rounds the hits off so, while you feel them, there’s a sense of control and sophistication. 

Having speed limits to contend with means it is essentially impossible to find the limits of grip of the 275/30R20 Continental SportContact 6 tyres on the road and there isn’t much body roll, either.

The RS4 is still rewarding, though, getting up on its toes just enough through a series of bends to feel engaging. It gives an impression of being quite light and at 1820kg it is now considered featherweight next to rivals.

The RS4's Quattro all-wheel drive system favours the rear wheels when driving normally (60 per cent rear) and can send up to 85 per cent of the drive to the back axle. 

The tweaked electronically-controlled rear limited-slip differential amplifies the throttle steer-ability of the RS4, giving you the confidence to squeeze the gas on exit. 

It helps that the Competition Plus bucket seats are a little thinner and set closer to the floor giving you more feedback. This is the key differentiator between the RS4 and RS5 we drove — the buckets make the car feel alive. 

Strong brakes are made up of 375mm front rotors clamped by six-piston calipers. Optional carbon ceramic brakes with larger 400mm front rotors help save 6.5kg and, if you plan to use the RS4 on track, are a smart buy along with a set of Pirelli P Zero Corsa semi slick tyres ($850). 

Really, though, neither the RS4 nor RS5 are the perfect car for the track. They are plenty capable and fast on the road with just enough fun, reward and character thrown in to keep you coming back for more.

The Audi A4 range was rated a maximum five stars in ANCAP safety testing in 2021, with the rating now considered expired. The stamp also only applied to four-cylinder models — so not the RS4 we drove. 

It has lots of safety equipment, including eight airbags (dual frontal, side chest, front and rear side head curtains), autonomous emergency braking (AEB) functional up to 250km/h with pedestrian detection, front and rear cross-traffic alert, lane-keep assist, blind-spot monitoring, safe exist warning and tyre pressure monitoring.

Adaptive cruise control with lane-trace assist makes it an easy car to use on the motorway. The systems are well integrated and easy to switch on and off as you like. 

The Alpina B5 is covered by BMW's three-year/unlimited kilometre warranty. Servicing is recommended every 12 months or 15,000km.

Audi covers the RS4 and RS5 with a five-year/unlimited kilometre warranty which is now the expected norm across the premium part of the market. 

A five-year service plan can be pre-purchased, costing $3630 for both models with maintenance due annually or every 15,000km. 

After the five-year warranty period, owners can choose to extend the service packaging and warranty for two extra years at a cost of $4260. This can be done twice, extending the warranty up to nine years.