The 1989's Mondial t was the final Mondial evolution . It was a substantially changed model, "spearhead of a new generation of V8 Ferraris", according to Road & Track magazine. It was visually different from preceding Mondial models, the most recognizable being the redesign of the air intakes to a smaller rectangular shape.
The 't' called attention to the car's new engine/transmission layout: the previously transverse engine mounted longitudinally while the gearbox remained transverse, thus forming a 't'. The 't' suffix was also homage to the first use of a transverse transmission by Ferrari in the highly successful Ferrari 312T, driven by F1 World Champion Niki Lauda.
By adopting this layout, a longer engine could be mounted lower in the chassis, improving handling dramatically. The 't' configuration was used by Ferrari's Formula One cars of the 1980s, and would be the standard for the marque's future mid-engined V8 cars, beginning with the 348, introduced later in the year. The transverse manual gearbox fitted with a Limited Slip Differential with a twin-plate clutch design with bevel gears driving the wheels. Later in production, a Semi-automatic transmission termed "Valeo" was available as an option; while shifting was using a traditional gear lever, the clutch was actuated automatically without a clutch pedal.
The engine was up to 3.4 L (3405 cc) and 300 hp (224 kW). The engine was controlled by Bosch Motronic DME 2.5 (later DME 2.7) electronic engine management that integrated EFI and ignition control into a single computer unit. Two of these were used in the car: one for each bank of the engine. Engine lubrication was upgraded to a dry-sump system.