Alpina have done it again, showing that high performance doesn’t need to come at the cost of subtlety or refinement - making the new B3 GT Saloon, B3 GT Touring and B4 GT a trio of fabulously understated outliers in a performance segment filled with overtly aggressively styled models. I like sleepers that don’t shout about their performance, and at first glance you could be forgiven for not expecting these cars to come with 522 bhp and 538 lb ft (730 nm) at their disposal, unless you know what you’re looking for.

The base of the front bumper sees a new splitter that contains the ALPINA wordmark in the centre, and subtle extensions with black-painted canards on the outer edges. The B3 GT has a wide hexagonal lower grille with intakes that divert air to hidden radiators, while the B4 GT has that tall kidney grille with a sea of silver bars and exposed outer radiators. Air channels feature on both cars that take air into the front wheel arches to reduce the turbulence caused by the magnificent 20” Classic forged alloy wheels when turning.

These are standard on the GT trio and are finished in a gold colour known as Oro Tecnico, with a diamond cut silver strip on and between each of the 20 spokes. Model-specific lettering also appears on the face of the wheel.

Gold pinstriping can stretch from the front wheel arches to meet the rear lights, providing a nice contrast to a dark exterior colour, or another subtle detail if white or grey paint is selected. At the rear, there’s another Alpina-specific splitter with quad-exit exhausts sitting either side of a four-strake diffuser, both finished in black. Model badging is gold, matching the wheels and the side striping. The B3 GT Saloon and B4 GT gain a pronounced lip spoiler on their bootlids…and that’s it. The Alpina GTs are refreshingly subtle and understated to my eyes, only dropping the slightest hints as to what lays within the engine bay.

The 522 bhp and 538 lb ft on offer comes from Alpina’s reworked version of the BMW S58 engine - the very same one that powers the M3 and M4. While this falls short of the M3 and M4 by 1 bhp, the Alpinas benefit from an extra 59 lb ft (80 Nm), with peak torque available from 2,500 - 4,500 rpm. The reworked engine mapping, which has gifted the car with an extra 34 bhp compared to its predecessor, is said to ensure that maximum performance is available in every driving situation, meaning for effortless progress when driving gently or rapid acceleration when you need to get a wiggle on.

The 0-62 mph times for all models begin with three; 3.4 seconds for the Saloon, 3.5 for the Touring and Gran Coupé. Keeping your foot down, 124 mph arrives in 11.6, 12.0 and 11.9 seconds for the Saloon, Touring and Gran Coupé respectively. Those of you who know your stats will recognise that the B3 GT Saloon’s acceleration times are ever so slightly quicker than those of the new M3! The GTs will keep on accelerating past the M3’s top speed, with 190 mph attainable.

Making the performance usable is an Alpina-specific version of the ZF 8-speed automatic transmission and a rear-biassed all-wheel drive system with an electronic limited slip differential at the rear. All of these changes are visible on a specification sheet, but some of the tweaks made to the chassis can be seen by opening the bonnet where you’ll be greeted with a pair of bulkhead reinforcement struts that increase rigidity and naturally, they’re painted gold.

New shock absorbers make their way to the B3 GT to take advantage of the stiffer chassis, but Alpina is keen to stress that improved handling does not come at the expense of ride comfort. The B4 also gets a retuned chassis, but one that is focussed on enhancing agility. This features new stabilisers with reinforced mounts at the front, leading to the steering and adaptive damping setups to be changed.

As the old saying goes: “When one bonnet closes, a door to the cabin opens”...or something like that. Anyway, that’s my smooth segue to start talking about the interior, which takes the same dual curved screen layout as the new 3 and 4 Series models, but with an Alpina-specific theme for the iDrive infotainment system. Carbon fibre trim is standard, along with Performtex velour upholstery for the seats, but what you really want is the leather that Alpina is famous for. Merino leather can be added to the seats and dashboard, while the LAVALINA option can see everything from the seat backs, centre console, door pulls and the piping on the floor mats be clad in leather. Yes please.

Regardless, the flat-bottomed steering wheel is finished in the soft LAVALINA leather with a subtle GT badge located beneath the airbag. The Oro Tecnico gold trim theme of the exterior continues inside with the colour appearing on the contrast stitching for the steering wheel, floor mats and headrest-mounted GT lettering, along with the aluminium shift paddles.

As with the exterior, Alpina-specific touches are hidden in plain sight, with the Alpina logo taking pride of place on the steering wheel, but also appearing on the carbon fibre dashboard trim and the floor mats. Next to the parking brake button is one of the two chassis plates that confirms the model and its build number. The other one is under the bonnet, ahead of the engine.

The GTs are filled with subtly special touches that separate them from the models that they’re based on, like the ALPINA wordmark on the gearshift paddles and the wheel hubs (yes, seriously), and the GT lettering on the door sills with a design that mimics the exterior stripes. They’re all hidden in plain sight on the cars and have been throughout this article too. It’s these details, along with the comfort-focussed performance ethos and subtle styling that make Alpinas such an appealing proposition to me.

For a car with impressive performance, styling and upholstery like this, it’s only natural for it to come with an impressive pricetag to match. These begin at £89,300 for the B3 GT Saloon, £90,400 for the B3 GT Touring and £91,400 for the B4 GT. The standard equipment is virtually identical with the estate getting a split-opening tailgate and the B4 gaining radar-guided cruise control which is an option on the B3s.

Naturally, I’ve been on the configurator and managed to inflate a Ken-spec B3 GT up to £111,750 with my choice of Alpina Green paint, the extended LALVALINA leather interior, adaptive headlights and head-up display contributing to the slight price lift. Deliveries are expected to begin in early 2025 for the UK market.

The trio of new GT models from Alpina are right up my street; I live in a part of the country that is prime M3 and M4 territory, so there’s something refreshing about the prospect of a car that can complete the task of rapidly devouring miles without turning heads or batting an eyelid. Alpina’s are meant to fly under the radar, but I will be scanning the roads for these.

Specifications: New Alpina B3 GT Saloon B3 GT Touring and B4 GT

Engine: 3.0 litre biturbo straight six

Power: 522 bhp at 6,250 - 6,500 rpm

Torque: 583 lb ft (730 nm) at 2,500 - 4,500 rpm

Transmission: 8-speed automatic

Drivetrain: xDrive all-wheel drive

0 - 62 mph: 3.4 s / 3.5 s / 3.5 s

0 - 124 mph: 11.6 s / 12.0 s / 11.9 s

Top speed: 191 mph / 190 mph / 190 mph

Kerb weight (kg): 1,875 / 1,945 / 1,965

WLTP fuel consumption: 26.9 mpg combined

OTR price from: £89,300 / £90,400 / £91,400

On sale: now