Carlo Chiti was the chief designer during 250 TR development and his continual experimentation counterbalanced Mr. Ferrari's conservatism and led to the many revisions that kept the car competitive through 1962.

[4][6][7][8][9][10][11] Included in this total are 19 "customer versions" of the 250 TR sold to independent racing teams, replacing the 500 TRC for this market.

The chassis gained a reputation for durability, as it was designed according to Enzo Ferrari's desire for absolute reliability even at the expense of excess weight.

Drum brakes were unpopular with drivers as they required tremendous physical exertion to operate, due to lack of servo assist and the extremely hard, long-lasting pads used for endurance races.

This hastily prepared prototype was based on a 290 MM chassis and had conventional bodywork by Scaglietti very similar to that of the 4-cylinder 500 TR, except for a large hood bulge.

Instead of the conventional fully enclosed front end, the new body had a distinctive cut-away nose reminiscent of a Formula 1 car.

The protuberant central air intake was now flanked by deep channels and the headlights were set into nacelle- or pontoon-like fenders that enveloped each front wheel.

The purpose of this design was to funnel cooling air inwards towards the brake drums, mitigating the persistent problem of heat-related fade.

The rear bodywork was more conventional, including a tapered fairing behind the driver's head and two small brake lights set into vertical fins.

Despite their radical appearance, racing and test runs soon showed that this design generated a significant amount of aerodynamic drag and high speed instability.

This was especially noticeable when competing on high speed courses such as the Circuit de la Sarthe against more aerodynamic cars such as the Maserati Tipo 61 and Jaguar D-Type.

[1][4][6][13][14] The 250 TR's open interior was simple and utilitarian, lacking the luxury trimmings found in Ferrari GT cars.

Like other 1950s and 1960s Ferrari sports cars, 250 TRs were equipped with an open gated shifter and a Nardi wooden steering wheel.

Despite this historiographical systematization, the low-production, hand-built nature of these cars and their use and modification in period mean that differences are most thoroughly explained in the context of an individual chassis' history.

[1][13] The body of the 250 TR again changed for the 1960 season, primarily due to new regulations requiring a windshield with a vertical height of 25 cm.

[1] Due to high drag and visibility problems with the TR60 body style, Ferrari engineers including Giotto Bizzarrini and Carlo Chiti were tasked with completely re-designing the 250 TR bodywork for the 1961 racing season.

[1] This front end styling had first appeared on a trio of Maserati 250Fs that Fantuzzi re-bodied in 1958 for racer Ross Jensen and team owner Temple Buell[18][19] (son of the architect with the same name).

Fantuzzi's suggestion that the twin intakes would improve air penetration was confirmed by Chiti's wind tunnel testing, leading to the adoption of this style throughout Ferrari's 1961 racing cars.

After testing the prototype with the deflector, driver Richie Ginther commented that high-speed stability seemed to improve with only a slight reduction in top speed, leading to the inclusion of this feature on all 1961 bodies.

[1] For the 1962 season, Ferrari developed the final iteration of the front-engined Testa Rossa, the 330 TRI/LM (LM standing for Le Mans).

[31] Notable drivers included Phil Hill, Olivier Gendebien, Luigi Musso, Peter Collins, Dan Gurney, Wolfgang von Trips and Mike Hawthorn, among them.

[1][13][14] Experimentation on 250 TR body styles from 1957 through 1962 provided Ferrari engineers with valuable experience in developing both low-drag and stability-promoting aerodynamic bodywork.

[46][47] The value, performance and historical significance ascribed to the 250 TR have motivated many individuals and companies to create reproduction automobiles.

Sold as a "replica", "recreation" or "reproduction", these can vary widely in historical accuracy and sophistication, sometimes using Ferrari engines and chassis or simply attempting to replicate the body style of the original with unrelated mechanical underpinnings.

[50] As 250 TR values rose, some extremely damaged or destroyed 250 TRs were reconstructed using varying amounts of newly fabricated or non-original components.

In at least one instance, this has resulted in a case of disputed identity, whereby multiple reconstructed or reproduced cars lay claim to a particular factory chassis number.