A decade ago, it would be the stuff of dreams to even contemplate a big, beefy, 155 mph four-seat German sports coupe averaging 31-to-the-gallon fuel economy.
But here we are, driving the potent new BMW 640i on an arrow-straight section of Florida Interstate, clocking-up readings of 30, 31, 32 to the gallon economy at a rock steady 70-or-so mph.
And it’s not just the high-gear highways where the swoopy Six excels. According to the folks at the EPA, you should be able to see 23 to the gallon around town. That’s pretty astonishing for a big sport coupe that tips the scales at a whisker over 4,000 pounds.
The secret here is the 640i’s brilliant twin-scroll turbocharged 3.0-liter in-line six that’s partnered with a new 8-speed ZF automatic. It’s essentially the same motor that pumps iron in BMW’s 335i sedan, cranking out a healthy 315-hp and 333 lb-ft of torque from just 1,400rpm.
If 315 horseys sounds a little on the dull side – let’s not forget a $24-grand Mustang V6 packs 3o5-hp these days – just wait till you put pedal to the metal.
With its ZF 8-speed firing off shifts with machine gun rapidity, the 640i can lunge from rest to 60mph in just 5.4 seconds, and won’t quit accelerating till the speed limiter calls “game over” at 155mph.
Of course, if you want ultimate performance in a 6-series, you can opt for the bad-boy 650i with its 400-horsepower twin-turbo 4.4-liter V8. That’ll get you to 60mph in five seconds dead while delivering a NASCAR-like soundtrack.
But after a day’s drive in the 640i, all I kept thinking of was why pay the $9,400 extra for the V8 – $73,600 versus $83,000 – and get 25 per cent worse fuel economy (15mpg city/23 highway)?
And so refined and oily-smooth is the power delivery of the in-line six – it seems to have dispensed with even the remotest hint of turbo lag – there are few performance sacrifices to be made by not having the big V8.
Toggle through the 640i’s four-mode driving dynamics software to Sport+ mode (there’s also Eco, Comfort and Sport to chose from) and the car’s steering, suspension, engine response, transmission and brakes all stand to attention.
Now play with the paddle shifters, stretch the straight-six all the way to its 7,100rpm redline, and the 640i surprises and delights in its eagerness and response. This is one fun car.
And despite its XXL-sized dimensions – nose to tail it measures 193 inches – it never feels bulky on the road. The electric-assist steering is precise and nicely-weighted, there’s massive grip from the 19-inch rubberware, and the car’s adjustable suspension keeps the car balanced through curves. That said, it’s still a big car that drives “big”.
At this high end of the market, it’s rare that buyers wouldn’t want to go for the best and most-powerful. But in the case of the 640i, you can spend less to get more.