The fastest cars you can buy for £20,000

09th May 2024

Russell Campbell

It would have been all too easy to fill this list with a line of RS models, AMGs and BMW Motorsport machines, but as they all (or most) come with a 155mph speed limiter, they miss the cut on this occasion. On the plus side, it means we can offer an altogether more eclectic mix of machines covering everything from barges to GTs, sports cars, muscle cars and luxury limos – these are the fastest cars you can buy on a budget of £20,000.

Alpina B10 V8 – 176mph

Burdened by its 155mph speed limit, the BMW E39 M5 – a legend of the super saloon world – doesn't make it onto this list. Instead, pragmatism, in the form of the Alpina B10 V8, is what's needed.

Trying to improve on one of the world's best-performance saloons is no easy task, so instead of beating the E39 M5 at its own game, Alpina went its own way with the B10, building it specifically for road use. Thus, the M5's high-revving motor got swapped for a V8 torque monster and its manual six-speed gearbox made way for a five-speed slushbox. The B10 defies its rubber band tyres by serving up a creamy-smooth ride, and Alpina removed the M5's limiter, meaning the B10 can waft to an Autobahn-ready 176mph. Marvellous.

Bentley Arnage T – 179mph

The Bentley Arnage T is arguably the last true Bentley before the company's ownership passed to the (admittedly far more competent) hands of Volkswagen, transforming the struggling British titan into a runaway success. Nevertheless, romantic sods like me feel some of Bentley's past magic was lost transitioning to successful car building.

You could argue the Arnage isn't a real Bentley either. It used BMW electronics and the company's valve-stem-munching V8. But the T was different. After owner protests, the definitive 6.75-litre V8 returned to duty, serving up a scarcely believable 1,000Nm (732lb ft) of torque from 3,200rpm – enough to surge this four-wheel manor house to a 179mph top speed.

Porsche 997 Carrera S Cabriolet – 182mph

The Porsche 997 Carrera S Cabriolet joins this list in the spirit of compromise – compromise because this scalpel-sharp sports car is sampled best as a coupé. But then, this isn't a list of the best cars with a roof and torsional rigidity; we want the highest speed we can get for 20,000 of your earth pounds.

Under this criteria, the Cabriolet scores surprisingly well. Being the less sought-after model brings this 997 into budget, and losing the roof brings its howling 3.8-litre flat-six into close proximity to your ears, which is less of a compromise all around. It also buys a manual gearbox instead of the clunky auto in the cheapest coupés. Roof or not, the 997 – with its natural aspiration, small dimensions, and hydraulic steering – is close to peak Porsche and one that can transform itself into an 182mph hairdryer.

Maserati Gran Turismo S – 183mph

Bless the Italians for their arm-flailing disregard for build quality and reliability. It means gorgeous cars like the Maserati Gran Turismo can be scooped up for under £20,000, thousands of pounds less than VW charges for a new Polo – someone pass the smelling salts.

With a concave grille, football-pitch-long bonnet and sculpted haunches worthy of Michelangelo, the Maserati is jaw-droppingly beautiful yet somehow manages to be a usable four-seater. Our budget is enough to scoop up an S model with the uprated 4.7-litre V8 producing 440PS (323kW) and the kind of mellow roar that only a Ferrari V8 with a cross-plane crank can make. Automatic as standard, the Maserati will never match the feels of a Ferrari, but when it weighs a hefty 1,900kg, that's not such a bad thing. Either way, this big GT tops out at a giddy 183mph.

Aston Martin DB7 Vantage – 184mph

The Aston Martin DB7 Vantage occupies an automotive no-man's land that makes it ripe for a list of the fastest cars you can buy for £20,000. The Aston is too young to be a proper classic and too old to be cool, but mark our words: like a Barbour wax jacket, its time will come around again.

For now, though, its fashion hiatus means you can pick up a DB7 Vantage – complete with a stonking 5.9-litre V12 – for well under our self-imposed budget. The V12 was the perfect match for Aston's continental crusader, giving it mind-bending flexibility that meant you could conquer a country without ever having to shift out of fourth. Sadly, our budget does come with one – slight disclosure – you'll need to choose the automatic gearbox. However, considering the DB7 is based on the ancient Jaguar XJS, that is probably for the best.

TVR Cerbera – 185mph

The 4.5-litre Cerbera's 185mph top speed comes with a minor disclaimer. Like everything with TVR, the official top speed is something of a mystery – it could be 185mph, or it could be around the 170 mark. Whatever it is, we doff our caps to anyone brave enough to confirm the true number.

In the Cerbera, speed is more than just a number. The TVR's famously spiky handling made it a challenge to drive at well below V-Max, and we'd be keen to avoid testing the crash-worthiness of a fibreglass body underpinned by a steel backbone chassis famed for rusting through. Despite all this, the Cerbera has more character in its non-existent door handles than the rest of the cars on this list combined, thanks to its bruiser looks, in-house-made V8, and extraterrestrial interior.

Alpina B7 – 186mph

The B7 is the second Alpina to make it to this list, as we reward the standalone German brand for its gleeful disregard for speed limiters. Based on the E65 BMW 7 Series, the B7 comes from the Chris Bangle-design era, and is all the better for sporting a contemporary chunkiness that still looks fresh today. It's even better with Alpina's dished alloy wheels, pinstripe graphics, and (not so) shy and retiring body kit.

Alpina is famed for its comprehensive tuning jobs, but the B7 takes things up a notch. Starting life as a 745i, Alpina bolted on a supercharger with power swelling from an adequate 333PS (245kW) to a ‘that’ll-do-sir’ 507PS (373kW), enough to get this wafty barge from 0-62mph in 4.4 seconds and onto a top speed of 186mph. Sadly, to the best of our knowledge, B7s were never officially imported to the UK, but JDM imports exist if you can find them.

C6 Chevrolet Corvette Convertible – 186mph

Much like the Porsche further up your screen, you'll have to settle on a convertible model to get your hands on a C6 Chevrolet Corvette capable of doing 186mph on a £20,000 budget.

That's about where the similarities between the Porsche and the Chevrolet end, though. Where the 911 relies on a sophisticated flat-six and a rear-engined chassis perfected over decades, the Corvette has an old-school V8 mated to leaf spring rear suspension. Sophisticated, it isn't, but the Corvette is quick. With a fibreglass body, this tips the scales at under 1,500kg, which, combined with 410PS (302kW) and 565Nm (403lb ft) of torque is enough for 0-62mph in 4.1 seconds and 186mph flat out, all accompanied with the rumble of Detroit muscle.

Porsche Panamera 4.8 Turbo – 194mph

The original Porsche Panamera Turbo looked like an abomination when it went on sale in 2009. It still does now, but hidden under the fugly design is an exceptional executive express with interior quality and dynamics that could mix it with and, more often than not - beat the best two-door GT equivalents coming out of the UK, Germany and Italy.

The Panamera releases its full, four-door GT character in Turbo form, where it gets huge horsepower, sophisticated air suspension with active anti-roll bars, and four-wheel drive with a trick rear diff that lets you drift like you're on a skip pan. The combined result is a car that can handle like a big sports car while carrying its occupants over serious mileages in complete comfort and at speeds of up to 194mph.

Bentley Continental GT – 198mph

Unusually, the fastest and last option on our list also represents the best value, with the elephant-in-the-room caveat that if anything goes wrong with your Bentley Continental GT, you'll need a black hole-like budget to fix it.

Nevertheless, the fact that you can pick up a wood and leather-lined GT from one of the most prestigious brands going for well under £20,000 seems mad. It's even crazier when you consider the performance on offer. The VW-derived twin-turbocharged W12 misses the charisma of Bentley's own V8, but it makes up for that with a 0-62mph in 4.6 seconds and 198mph top speed that should make the double-tonne achievable with the help of a gentle slope and tailwind.