Ford Performance chief engineer reveals the answer.
The Mustang and the F-150 are far and away Ford's two most important assets. The F-150 dominates the sales charts as America's most popular vehicle—it racked up nearly 900,000 sales last year and is on pace to break its own record this year with 941,000 predicted US sales. While the Mustang sells in far smaller quantities, it serves as the brand's figurehead thanks to its legendary reputation and iconic styling. Even with Ford slashing its car portfolio in the coming years in favor of an expanded arsenal of SUVs, the Mustang will remain a key part of the lineup.
However, while the base versions of both the F-150 and the Mustang were facelifted for the 2018 model year, their high-performance counterparts, the F-150 Raptor and Shelby GT350, are scheduled to remain unchanged, according to a recent statement from Ford Performance chief engineer Ed Krenz.
Speaking at a recent launch event in Utah for the 2019 F-150 Raptor, Krenz confirmed that the models will not receive the visual tweaks of their lesser brethren, and explained that this was due to cost. For example, to align the Shelby GT350's design with the base model's styling, it would need an all-new front bumper, headlights, fenders, and hood. These changes would not only be expensive to implement but would also have no performance benefits for the GT350.
This is not to say the Shelby will continue as is, with several performance upgrades coming for 2019. New Michelin Pilot Sport Cup 2 tires with a tread pattern made specifically for the GT350 replace the Michelin Pilot Super Sport tires and provide more grip. Improved aero comes in the form of a new Gurney flap on the rear decklid and a redesigned grille. The suspension and the electronic aids were also revised to supply the driver with more communicative feedback.
With the Raptor, Krenz claimed they shied away from spending on visual changes because "[w]e invest in suspension." To that end, the 2019 Raptor will get new Fox 3.0 Bypass shocks that can adapt in real-time as well as a new electronic Trail Control system that aims to make the truck smarter off-road. The wheels and engine cover receive minimal changes, while Recaro seats are now offered inside.
Despite the lack of visual updates, the F-150 Raptor and Shelby GT350 remain some of the most capable, and best looking, performance cars on the market.