Allegedly due to lack of demand
The ST is definitely our favorite version of the Ford Fiesta, but it’s far from the only one that’s fun to drive. In fact, the Fiesta with the smallest engine Ford puts in a car ended up being an absolute blast. Its tiny 1.0-liter turbocharged I-3 only makes 123 hp and 148 lb-ft of torque, but it’s remarkably refined and a hoot to wring out. Sadly, it won’t be an option for U.S. customers anymore.
In an email, Ford told us that if you want to buy a Fiesta, you’ll only have two engines to choose from: a naturally aspirated inline-four and the ST’s turbocharged four. The three-cylinder has been dropped from the U.S. Fiesta lineup. Ford says this decision was made “based on customer demand.”
Considering how much we enjoyed that little 1.0-liter, this is disappointing news. But at the same time, it was probably inevitable. Subcompact sales are down overall in the U.S., and the three-cylinder cost about $1,000 more than the base engine. It offered more torque and better fuel economy, but the mpg gains were minimal. Plus, while an automatic was added later, the 1.0-liter Fiesta was originally launched with a manual transmission as your only option.
So if you were waiting to pull the trigger on a new 1.0-liter Fiesta, go ahead and get one while you can. If you just want the novelty of owning a three-cylinder car (and not necessarily a fun one), the engine also appears to still be available in the 2017 Focus.
Source: Ford