life. These include: 1986: A central high-mounted stop light is integrated into the lower rear wing. Windows now roll down below sill edge. Driver's side wiper airfoil is dropped. Turbocharger outlet tube is now smooth. Heater core is upgraded. (Late year change) 1987: The XR4Ti inherits many upgrades from the European Sierra Mk.II chassis, including a wider transmission tunnel and different pedal spacing. A monochromatic paint scheme that matches the lower body cladding color to the rest of the body becomes a mid-year option. Colors are black, red or white. The standard alloy wheels are upgraded to 15-inch 8-slot "pie-spoke" units. Tires are now Pirelli P6 195/60HR15. The dashboard is redesigned to address premature cracking experienced by earlier cars. The diamond-shaped `Merkur' badge on the rear is replaced with simple “Merkur” text on the deck-lid. The fender-mounted antenna is replaced by an antenna trace bonded to the glass of the rear hatch. Redesigned steering reduces turns lock-to-lock to 2.42, and turning circle to 35.4 feet. The engine receives a new cam cover. The sound system is changed. Joystick balance control is removed. Three new paint colors are available. Oil level sensor and dash indicator is deleted. 1988: The bi-plane rear spoiler is replaced by a simpler single-level wing. The rear hatch gets a larger glass panel in the hatch with the change of wing, which combines to raise the coefficient of drag. The standard alloy wheels are changed to a BBS-style cast wire-spoke model. Beige/brown cladding now offered depending on body color. Speedometer scale now goes to 150 mph. New interior colors are available. 1989: The dashboard ends are shortened slightly to allow the A-pillar trim to extend past it. Cruise-control becomes standard equipment. Coolant overflow bottle is relocated. In addition to the changes above many modifications were incorporated as Technical Service Bulletins. A number of automotive customizers produced versions of the XR4Ti that offered increased performance and improved handling. Among these companies were Roush, Rapido, and RC Consultants. These versions were often sold as either owner-installed kits or pre-built vehicles. One such special, built by Ralph Todd and called the Scorch XS replaced the Ford engine with a Nissan VG30DETT twin-turbocharged V6. Only one of these US$50,000 conversions was built; Scorch Prototype #001. The other Scorch cars were never completed and ultimately dismantled. Ford only offered one special edition of the XR4Ti when, in a 1987 tie-in with ski