Bugatti may have developed an original sixteen-cylinder engine for the Veyron, but it's not the only one out there.
Top 5?! We've got to be kidding, right? Only we're not. Because while the Bugatti Veyron may be the only sixteen-cylinder car currently in production, there have been others. And we're not even counting the concepts that previewed the Veyron or the many versions that have followed, either. Nor are we counting the egg that is the Galibier concept before it's hatched, either. Each car on this list is a stand-alone design from a different company. In fact, each of them comes from a different country altogether.
The first car to come to mind when it comes to sixteen-cylinder engines, of course, is the Bugatti Veyron. The earliest prototypes incorporated an eighteen-cylinder engine, but by the time the Veyron reached production, it had ditched a couple of cylinders but added a quartet of turbochargers to bring output up to 1,000 horsepower. The cylinders are arranged in a unique W configuration (essentially made out of two V8s) pioneered by Volkswagen, allowing it to fit into a much smaller space than a conventional V design. Still, displacing eight liters, the engine is so massive that it uses 64 valves and ten radiators to keep it going.
Cadillac's history of producing sixteen-cylinder engines traces way back to 1930 when it made the Cadillac V-16. It produced barely more than 4,000 of them over the course of eleven years, but over six decades later, Cadillac brought the formula out of the archives with the Sixteen concept of 2003. As different from the Veyron's as a sixteen-cylinder engine can get, the concept incorporated a 13.6-liter V16, naturally aspirated with 32 valves and driving the rear wheels through a four-speed automatic transmission. Plans for a smaller V12 sedan were ultimately shelved in favor of the XTS, which can be had with a V6 or a turbo four.
When BMW bought Rolls-Royce, it sought to take the brand in an even more upscale direction with the 100EX. The prototype featured a 9.0-liter V16, derived from the Goldfish engine program originally envisioned for the BMW 7 Series. In the end, BMW opted for a more conventional V12 engine for the Phantom (as it had for the 750i), displacing the traditional 6.75 liters. Rowan Atkinson convinced Rolls to let him use the sixteen-cylinder Phantom prototype in his movie "Johnny English Reborn". But recent reports have indicated Rolls could revive the engine design for a new flagship roadster.
Before Cadillac, Rolls-Royce and Bugatti toyed with the idea of modern V16, Cizeta made a sixteen-cylinder supercar. A joint effort between a Ferrari dealer, a record producer and a Lamborghini designer, the Cizeta V16T was based on the original design for the Diablo, and featured a sixteen-cylinder engine made up of a pair of V8s mounted transversely (not turbocharged as the letter T might suggest) displacing 6.0 liters and producing 540 horsepower. Cizeta only made 11 examples between 1991 and 1995, each selling for $300,000 – a mammoth price tag for its time that was eclipsed only by its outrageous, but not unprecedented cylinder count.
Although there are other sixteen-cylinder engines to be found in the annals of automotive history, one of the earliest and most influential was that made by Auto Union. A precursor to today's Audi, Auto Union built a V16 engine for its famous Type C race car that contested pre-war grands prix before the advent of the modern Formula One series. The Auto Union Type C battled Mercedes-Benz as part of Nazi Germany's Silver Arrows racing program and won numerous races. Only one sixteen-cylinder Type C is known to be in existence, restored by Audi in 1979 after it had been destroyed during wartime bombing raids.