World’s Slowest Ferrari Still Costs a Fortune on Bring a Trailer

There are many reasons to buy a Ferrari: style, exotic engine noises, driving thrills, and showing your neighbors who's the richest. But mostly, they're built for speed. While some Beverly Hills Ferrari owners may never exceed 15 mph—so the plebs can see who's driving a car more expensive than their home—buying a speed-capped Ferrari isn't something many car enthusiasts would want. Yet, this 2014 Ferrari F12tdf prototype for sale on Bring a Trailer has a top speed of just 15 mph, and someone still wants it badly enough to bid $450,000.

How can a V12 Ferrari be limited to just 15 mph, and why would anyone bid such an eye-watering amount of money for it? According to the listing, this F12tdf prototype was actually a modified F12 Berlinetta that was used as a development mule for the eventual, very special-edition F12tdf. Once its duty as a development mule ended, Ferrari detuned its engine and software-limited it to just 15 mph. After being detuned and put out of commission, a dealer imported it to the United States as a show and display car. Now, it's being sold by that dealer, but it isn't legal to register for road use.

What good is a 15-mph Ferrari that can't be registered for the road? Well, it seems possible to retune it (untune it?) back to its original power, since the 6.3-liter V12 appears to be mechanically normal. Test mules like we have here, as well as concept cars, are often hobbled when they pass from the OEM to the private market. Sometimes automakers go to rather extreme lengths, like pouring concrete in the cylinder bores, that are a bit harder to reverse engineer. The fact this F12's limitations are software-induced perhaps gives it an outside chance at returning to its true potential. Whether it can muster the full 770 horsepower of the production F12tdf is unknown, though.

Even if this development car can be unlocked like a secondhand iPhone, whoever buys still won't be able to register it for road use. That means it's only good for track duty, or as a display car. The F12tdf was always meant to be a track-focused version of the normal coupe, so maybe that isn't a big problem.

But why not just buy a real F12tdf instead? Well, depending on how