2015-2017 Ford Mustang Convertible VI GT 5.0 V8 (426 Hp)

The Ford Mustang Convertible VI GT 5.0 V8 (426 Hp), produced from 2015 to 2017, represents a significant chapter in the Mustang’s evolution. This sixth-generation Mustang, internally designated the S550, was the first designed from the outset for global sales, expanding its reach beyond North America to markets in Europe, Asia, and Australia. The convertible variant offered an open-air driving experience powered by a potent V8 engine, blending traditional Mustang characteristics with modern engineering and design. This particular model occupied a mid-to-premium position within the S550 lineup, offering a substantial performance upgrade over the EcoBoost models while remaining more accessible than some of the higher-performance special editions.

Powertrain & Engine Architecture

The heart of the Mustang Convertible VI GT 5.0 V8 (426 Hp) is the “Coyote” 5.0-liter (4951 cm³ or 302.13 cu. in.) V8 engine. This naturally aspirated engine, featuring an aluminum block and cylinder heads, delivers 426 horsepower at 6500 rpm and 529 Nm (390.17 lb-ft) of torque at 4250 rpm. The engine code remained consistent with the US market Coyote engines, though some international markets received slightly detuned versions to comply with local regulations. The 426 hp output was common in many export markets. The Coyote engine utilizes a dual overhead camshaft (DOHC) valvetrain with four valves per cylinder, maximizing airflow and combustion efficiency. Fuel delivery is managed by a multi-port fuel injection system, contributing to both performance and the characteristic V8 exhaust note. A compression ratio of 11:1 necessitates the use of premium gasoline (petrol). Power is transmitted to the rear wheels through a six-speed automatic transmission with SelectShift functionality, allowing for manual gear selection via steering wheel-mounted paddle shifters or the gear selector. This transmission was a key differentiator from the standard six-speed manual transmission offered on the GT models, targeting buyers who preferred the convenience of an automatic.

Automatic Transmission Details

The 6R80E six-speed automatic transmission used in the Mustang GT is a robust and well-regarded unit. It features a torque converter lock-up clutch that engages in higher gears to improve fuel efficiency and reduce slippage. Gear ratios are optimized for both acceleration and highway cruising. First gear is relatively short for quick off-the-line acceleration, while higher gears are geared for lower engine speeds at highway speeds. The SelectShift functionality allows drivers to manually select gears, providing a degree of control without the need for a clutch pedal. The transmission is electronically controlled, adapting shift points based on driving conditions and throttle input.

Driving Characteristics

The 2015-2017 Mustang Convertible VI GT 5.0 V8 (426 Hp) with the automatic transmission delivers a compelling driving experience. While not as directly engaging as the manual transmission variant, the automatic provides smooth and responsive shifts, making it well-suited for both daily driving and spirited performance. Acceleration is brisk, with the V8 providing ample power throughout the rev range. The automatic transmission’s programming prioritizes smooth transitions, but the SelectShift feature allows drivers to take control when desired. Compared to the manual transmission GT, the automatic version typically achieves slightly slower 0-60 mph times, but the difference is often minimal. The convertible body style adds some structural flex compared to the coupe, but the chassis is well-tuned to minimize this effect. The overall driving experience is a blend of raw power, comfortable cruising, and the open-air enjoyment of a convertible.

Equipment & Trim Levels

The GT Premium trim level was the most common configuration for the 2015-2017 Mustang Convertible VI GT 5.0 V8 (426 Hp). Standard features included leather upholstery, heated and cooled front seats, a premium audio system (often a Shaker Audio system), dual-zone automatic climate control, and Ford’s SYNC infotainment system with an 8-inch touchscreen display. Optional extras included navigation, blind-spot monitoring, rear cross-traffic alert, and a power-adjustable steering column. Exterior features typically included 19-inch alloy wheels, a rear spoiler, and HID headlights. The convertible top was power-operated and available in a variety of colors. Interior color options included black, saddle brown, and ruby red. The GT Performance Package, a popular option, added performance upgrades such as Brembo brakes, a Torsen limited-slip differential, and unique suspension tuning.

Chassis & Braking

The S550 Mustang featured a significant chassis upgrade over previous generations, including an independent rear suspension (IRS). This IRS system, a first for a production Mustang, greatly improved handling and ride comfort. The front suspension utilizes MacPherson struts, while the rear employs a multi-link design. The chassis is constructed with high-strength steel, providing a rigid and stable platform. Braking duties are handled by ventilated disc brakes at all four corners. The GT models typically featured larger brake rotors and calipers than the EcoBoost models. ABS (Anti-lock Braking System) is standard, along with electronic brake-force distribution and traction control. The steering system is electric power-assisted steering (EPAS), offering adjustable levels of assistance.

Market Reception & Comparison

The 2015-2017 Mustang Convertible VI GT 5.0 V8 (426 Hp) was generally well-received by automotive critics. It was praised for its performance, handling, and modern design. The automatic transmission was noted for its smoothness and responsiveness, although some reviewers preferred the engagement of the manual transmission. Compared to the EcoBoost Mustang, the GT offered a significant performance upgrade, justifying the higher price. Compared to the Chevrolet Camaro and Dodge Challenger, the Mustang was often seen as a more balanced package, offering a blend of performance, style, and refinement. Fuel economy was considered reasonable for a V8-powered convertible, averaging around 19 mpg combined. Reliability was generally good, although some owners reported minor issues with the infotainment system. The Mustang’s global availability broadened its appeal and helped it gain a foothold in new markets.

Technical Specifications

Legacy

The 2015-2017 Ford Mustang Convertible VI GT 5.0 V8 (426 Hp) remains a popular choice in the used car market. The Coyote V8 engine is known for its reliability and durability, and the 6R80E automatic transmission is also generally considered to be a robust unit. Regular maintenance, including oil changes and fluid checks, is essential to ensure long-term reliability. Common issues reported by owners include minor electrical glitches and wear and tear on convertible top components. The S550 Mustang’s independent rear suspension and modern features have helped it maintain its appeal, and it continues to be a sought-after vehicle for enthusiasts seeking a blend of performance, style, and open-air driving enjoyment. Its success paved the way for continued global expansion of the Mustang brand, solidifying its position as a true automotive icon.