This 2.9-litre V6 petrol engine has hardly any lag, despite being heavily turbocharged. Meanwhile, the fact that every upshift of the slick eight-speed automatic gearbox elicits a delicious crackle from the quad exhaust pipes when you’re accelerating hard in Race mode adds further to its appeal. It's just a pity the lesser modes leave the Stelvio Quadrifoglio sounding more like a three-cylinder hatchback than a 503bhp monster.