2029 Ford Mustang Mach-4 Sedan: Everything We KnowAndrei Avarvarii - MotorTrendWhat It IsAt this point, it's less a rumor and more a waiting game. Ford has made it clear in both private meetings and on-the-record interviews it intends to get back into making cars other than the Mustang coupe. In other words, the company wants to extend the "Mustang family," as executives call it. A four-door Mustang sedan concept has already been shown to dealers earlier this year, and the company trademarked the name "Mach-4," which follows the Mustang Mach-E naming convention.Why It MattersThe whole "Mustang family" thing isn't new, either, and the Mach-E was never meant to be a one-off. Ford sees the Mustang and Bronco not as individual models anymore but as subbrands ripe for expansion. That's why there's a little Bronco Sport and an electric Mustang Mach-E. The Mach-4 is how Ford will continue to grow the Mustang subbrand. It's also how Ford gets back into building sedans without having to spend too much money or build (or rebuild) a new brand from scratch.On the first point, modifying the existing S650 Mustang chassis, while not cheap, will cost less than engineering an all-new rear-drive car platform. Ford execs want this program to be cost-effective, and working with what you have is generally cheaper. Figuring out how to stretch the unibody will take a lot more than sawing the car in half and adding metal in between, but ideally, it'll be less work than starting from nothing. If that plan pencils out, it will also help get the car to market sooner.AdvertisementAdvertisementOn the second point, the Mach-E already proved most customers care more about looking cool than preserving the sanctity of the Mustang name. The EV crossover regularly outsells the gas-powered coupe by a wide margin, and the Mustang name and looks were always intended to increase its appeal, which is precisely what happened. Ford plans to pull the same trick twice with the Mach-4 sedan. Plus, people already know what a Mustang is, so the marketing department doesn't have to dust off an old, forgotten nameplate or invent a new one and then try to convince buyers to take a chance on it.Andrei Avarvarii - MotorTrendPlatform and PowertrainWe're confident the Mach-4 will be a modified Mustang coupe. The Mustang already has four seats, so two more doors and some rear legroom are all it really needs here. While it's possible the Mach-4 could herald the coming of a next-generation Mustang platform the coupe would also move to, we think it's unlikely given everything Ford execs have said about keeping costs down. It's also worth remembering that the existing S650 platform is just an evolution of the old S550 one, not an all-new bit of engineering. It's possible that when Ford updated the S550 to the S650, it baked in some of what would be needed to do a sedan.Further toward keeping costs down, we don't expect the powertrains to change. That means the 2.3-liter turbo four-cylinder and 10-speed auto is likely to be the standard setup, with the 5.0-liter V-8 optional and paired with either the 10-speed auto or six-speed manual.Wait, do we really think Ford would do a V-8 sedan with a manual transmission? Yes. The V-8 is a lock as far as we're concerned now that Dodge has confirmed the Charger will get a V-8. A manual transmission option will give the Mach-4 a unique selling proposition that Dodge can't currently match. Because the V-8 and manual transmission combination is already engineered for the Mustang platform, the incremental cost of emissions certification, calibration, and crash validation in the revised bodyshell should be manageable.Estimated Price: $37,000 (base), $50,000 (V-8)Expected On-Sale Date: Fall 2028