A vehicle identification number document filed by Ford with the National Highway Traffic Safety Administration (NHTSA) suggests that Ford could offer a third, more powerful turbocharged engine, according to a report by Hagerty. The VIN paperwork is for the 2020 model year so Ford could be about to announce a new, third engine choice in the regular, non-Shelby Mustang.
You can view the relevant chunk of the VIN decoder sheet Ford filed with the NHTSA over on Hagerty's website here, which shows the existing options for Mustang engines as well as a new "D" for a 2.3-liter inline four, listed as "TBA" in horsepower. The other new engine option for next year, per Bozi Tatarevic, the Hagerty writer who spotted the new turbocharged VIN registration, is the J on the sheet, which is the GT500 5.2L V8.
(Curiously, the sheet also lists the current V8 option as producing 435 hp instead of 460, but errors on VIN registration sheets are relatively common, Tatarevic told The Drive. In other words, I wouldn't panic about a neutered GT V8 based on this doc.)
According to unnamed sources at Ford who spoke with Hagerty, this new "D" engine is likely a higher-power variant of the current EcoBoost engine, tuned for more performance than the current base-model Mustang offers in 2019. While no exact figures were mentioned for what TBA could be, the Focus RS gets 350 hp from a slightly modified version of the same EcoBoost engine, and that would be just enough of a boost over the 335 hp V6 Chevrolet Camaro to make sense.
Ford dropped its base V6 Mustang from its lineup this year in light of the fact that the 310-hp EcoBoost model, which came with a turbocharged 2.3-liter four-cylinder engine, was only $1,000 more for a significant bump in power. The only other engine choice is the V8 that comes in the GT trim, which is an $8,960 jump in price, not to mention a big jump up to 460 horsepower.
There's clearly room for something in the middle, and not offering a middle option isn't a good look when the Chevrolet Camaro offers a range of three engine options—including a middle V6-powered Camaro with 25 more horsepower than the EcoBoost Mustang.
A Ford spokesman would not comment on the matter to Hagerty, telling them that the company "is always elevating Mustang and will share more exciting news this spring." That being said, this is one Mustang rumor that makes decent business sense, and the VIN sheet seems to back up that it could happen.
