The 348, badged 348 TB for the coupe (Berlinetta) and 348 TS (Spider) for the targa versions, features a naturally aspirated 3.4 litre version of the quad-cam, 4-valve per cylinder V8 engine which was originally found in the 288 GTO sports car. Thus the model name, 3.4 litre 8 cylinder engine. The engine produced 300 hp (224 kW) at launch and sits longitudinally with a transverse gearbox, like the Mondial t with which the 348 shares many components. This was a major switch for Ferrari, with most previous small Ferraris using a transverse engine with longitudinal transmission. The transverse gearbox gives the model its "T" on TS and TB. All 348s were shipped with dual-computer engine management with twin Bosch 2.5 Motronic ECUs, and double-redundant Anti-Lock Braking systems. Likewise, all 348s were shipped with on-board self-diagnosing Air Conditioning and heating systems. U.S. 348s have functioning on-board OBDI engine management systems, though European variants do not come with the self test push button installed, which is needed to activate this troubleshooting feature. Similar to the Testarossa but departing from the BB 512 and 308/328, the oil and coolant radiators were relocated from the nose to the sides, widening the waist of the car substantially, but making the cabin much easier to cool since hoses routing warm water no longer ran underneath the cabin as in the older front-radiator cars. This also had the side effect of making the doors very wide. All Ferrari 348s use racing "dry-sump" oil systems to prevent oil starvation at high speeds and in hard corners. The oil level can only be checked (accurately) on the dip-stick when the motor is running due to this setup. Likewise, all 348s have suspensions independently adjustable for ride height, as well as a removable rear sub-frame to speed up the removal of the engine for maintenance. Late versions (1993 and beyond) have Japanese-made starter motors and Nippondenso power generators to improve reliability, as well as the battery located within the front left fender for better weight distribution. Nearly 9,000 348s were produced, and the car's straked side air intakes resemble those of the Testarossa, as do the rectangular tail lights. The 348's successor, the F355, returned to the styling cues of the 328 with round tail lights and rounded side air scoops. Also, 57 "Challenge" models were made for owners who wanted a more "track-ready" car. This vehicle also served as a test mule for the Ferrari Enzo. Three of these were made.