2023 BMW Alpina B5 GT Outmuscles the BMW M5

German tuner Alpina has announced that its long-lived brand would be fully absorbed by BMW in 2025. Now the time has come to start saying farewell, with the limited-run Alpina B5 GT—just going on sale in Europe and Asia, but not headed to the U.S.—set to be Alpina’s last version of the 5-series.

The term “tuner” doesn’t really do justice to the closeness of Alpina and BMW’s long relationship. Alpina has always been a separate company and is registered in Germany as an independent automaker. But it has also worked with BMW on projects including its high-performance XB7 version of the X7, as well as running race programs and doing contract engineering work for BMW. The level of trust was such that Alpina typically has been given access to new models well ahead of them going on sale, so it could start working on its own variants.

Alpina’s 5-series history

Many of the most famous Alpinas have been based on the 5-series, although few of those have reached the U.S., where the brand has normally only imported its largest and most expensive models. The first Alpina version of the mid-size sedan was the E12-generation B7 Turbo launched in 1978, with a turbocharged version of BMW’s 3.0-liter straight six giving it a 155-mph top speed. (At the time, the brawniest car in the regular E12 range, the 533i, could only go 132 mph.) Aimed at the German market, where unrestricted autobahns made top speed relevant, Alpina had found a niche. Faster fives followed: By 1989, the E34-based B10 Bi-Turbo could do 180 mph, and the B5 GT has upped that to 205 mph.

Yet that figure is a conservative one, according to Alpina CEO Andreas Bovensiepen—in testing, the B5 GT has gone considerably faster. B5 buyers also tend to use their cars hard, with Bovensiepen saying that 30,000 kilometers (about 18,600 miles) is the typical annual mileage for cars sold in Germany.

The B5 GT is an evolution of the B5 that has been on sale since 2018. The model is based on the M550i and uses the same N63-generation twin-turbo 4.4-liter V-8, which is also the base for the M5’s S63. The GT has more power than the regular B5 or the standard M5, with a revised intake system and a new ECU taking its peak to 625 horsepower, 26 more than the regular B5 and just two horsepower less than the mighty BMW M5 CS. But the GT wins on torque with a huge 627 pound-feet, which is 74 pound-feet more than the M5. The GT also has a center exhaust section to give it a more muscular tone.

Compared to the regular B5, the GT also has a new reinforcement piece on its front bulkhead to improve steering precision, stiffer bump-stop rubbers, and new brake pads. Spring rates, plus settings for the active anti-roll bars and rear steering, are unchanged. The GT rides on bespoke Pirelli P Zero tires that have been developed specifically for Alpina, and they wrap the brand’s traditional 20-spoke alloys, now with an optional bronze-gold finish.

The GT also gets some small “dive plane” wings on the sides of its front bumper to improve high-speed stability. Both sedan and Touring station wagon versions are offered, and the limited production run will consist of 180 Tourings and just 70 sedans. The full allocation is sold-out despite a price in Germany that starts at $137,500 at current exchange rates.

Alpina B5 GT on the track

Sadly, we didn’t get to experience the B5 GT in its natural autobahn environment, but rather on the Zandvoort racetrack in the Netherlands. High speeds were possible but only fleetingly given the limited length of the 2.6-mile circuit’s few long straights. The Alpina coped impressively well with the challenging environment, especially considering a storm the previous day had washed Zandvoort clear of much of the blown sand that often limits adhesion here.

While the comparison to the BMW M5 is an obvious one, the B5 GT’s character is very different. Whereas the M5 is revvy and angry, the Alpina is much more about low-down muscle. Peak torque arrives at 3500 rpm, and there is little discernible lag; even in Zandvoort’s tightest corners, third gear often seemed a better choice than second. The torque-converter transmission isn’t as quick as a dual-clutch unit but still shifts snappily in its Sport and Sport Plus modes. Manual gear selection is possible through steering-wheel paddles, but leaving the gearbox to its own devices in Sport mode seemed to work nearly as well.

Chassis settings are softer than those of the M5, yet body roll is well contained even at track speeds, and the GT’s steering feels crisp and natural. In tight corners, the B5’s front end tended to edge wide under big loadings. The Alpina has all-wheel drive but with a conventional limited-slip differential rather than a torque-vectoring unit. The rearward bias of the power delivery is obvious, but it takes real provocation to make the GT surrender rear-end grip.

Switching to the Touring proves that the driving experience is similar, although the novelty factor is much higher. Alpina says the Touring is 220 pounds heavier than the sedan and loses a little structural rigidity, but differences at Zandvoort were limited to the different perspective in the rearview mirror and what seemed to be slightly more noise from the rear of the car. BMW has recently confirmed it will be making a Touring version of the next-generation M5; that will have to be very special to be a more compelling all-rounder than the B5 GT Touring.

Sadly, the B5 GT will be the last of its line. Bovensiepen says the logic behind the decision to sell the family-owned brand was simple: Third parties won’t be able to add significant performance to EVs. Alpina’s Classic division will continue and has plenty of greatest hits to work with—the B5 GT is set to be remembered as one of them.

Senior European Correspondent

Mike Duff has been writing about the auto industry for two decades and calls the UK home, although he normally lives life on the road. He loves old cars and adventure in unlikely places, with career highlights including driving to Chernobyl in a Lada.