Interior

• The Testarossa's interior holds up well if properly taken care of. If the leather is subjected to a lot of wear, however, the seat bolster seams can become frayed and come apart. Likewise, the upholstery around the dash and instrument binnacle can warp and lift. The early Testarossa came with an automatically retracting seatbelt, which has been known to stop functioning.
  
  

Engine

• The Testarossa's engine was an all new 4962 cc flat 12-cylinder that featured four-valve heads and put out 390 bhp and 362 pound feet of torque. Like all Ferrari 12-cylinders, this is a robust engine that with the proper maintenance is quite reliable. It is, however, quite expensive to maintain, with a full service running in the $6,000 to $10,000 range. The Testarossa's catalytic converters have been known to go bad and catch fire, causing the engine bay to go up in flames, a potentially disastrous situation.
  The factory had a few updates over the car's production run, including a water and oil pump driving-chain update, an updated air pump and an updated alternator belt and pulley.
  
  

Driveline

• The gearbox on the Testarossa is, like the motor, pretty robust. There can be issues with the differential, which isn't always up to the task of transmitting all of the horsepower and torque to the rear wheels. Testarossa differentials have been known to self destruct, particularly on high mileage examples, requiring a replacement. The silver lining here is that the diff can be replaced with a stronger, updated version from the 512 TR, which is more durable.
  The Testarossa's gearbox needs to be warmed up properly before the driver can use 2nd gear aggressively. If this is neglected, the 2nd gear synchro can wear out, causing a "graunching" noise when shifting.
  
  

Wiring

• The wiring on the car is quite complex and while problems are not necessarily common, if there are issues here, they can be time-consuming to put right. As mileage increases, the chances for electrical issues increase.
  
  

Summary

• The Testarossa is a complex, expensive car to maintain. Cared for properly it is also a fast, reliable GT. Many owners have used these cars as daily drivers and there are quite a few examples that have been driven 100,000+ miles. Most of the problems with these cars can be prevented with the proper maintenance.