The engine in this test car looks identical to the 5.0-liter V-8 that powers the Mustang GT, as evidenced by the intermeshed intake runners and black “Powered by Ford” cylinder-head covers. It’s too early to say whether the engine will receive any upgrades for the next-generation Mustang; the 5.0-liter V-8 currently produces 420 hp and 390 lb-ft of torque in the Mustang GT, while a tuned version in the Boss 302 offers 444 hp and 380 lb-ft. 
Even if the 5.0-liter stays in place, Ford will need a base engine for the new Mustang. There’s a possibility the standard 3.7-liter V-6 will stay in place, but other reports suggest Ford may introduce a 2.3-liter turbo-four engine either as an option or to replace the base V-6. The forced-induction engine would not only be more powerful than the current Mustang’s base V-6, with about 320 to 350 hp, but it also should be significantly more fuel efficient.
There’s a 5.0-litre V8 engine
Ford Mustangs 