body panels made of synthetic materials. The nose and the cockpit surround were made of fibreglass later in the season. The aluminum fuel tanks had a capacity of , and were located in the car's nose and on both sides next to the driver's seat. The cockpit was narrow and contained the driver's seat, the steering wheel, the shift lever, and the pedals. A tachometer in the middle of the instrument panel and oil pressure and oil temperature gauge gave the driver the most necessary information. The 804 weighed approximately ; only slightly above the regulated minimum weight of . Suspension The suspension front and rear comprised unequal-length upper and lower A-arms. At the front, the suspension initially had only one radius rod on the bottom end of the upright. An upper rod was added later. Also at both front and rear, springing was provided by longitudinal torsion bars, and damping was by either Koni twin-tube or Bilstein monotube shock absorbers, mounted inboard. A front anti-roll bar attached to the inboard extensions of the upper A-arms. The 804 was the first Porsche to come standard with disc brakes. The car used Porsche's unique annular ring system. The 804 was also the first Porsche equipped with rack-and-pinion steering. The car was fitted with 15-inch wheels front and back. The wheels were steel, in contrast to the magnesium pieces being used by some of the competition. The tires were 5.00–15 R tires in front and 6.50-15 R in the rear. Engine and transmission Design of the new Type 753 flat-eight engine for F1 was handled by Hans Hönick and Hans Mezger. The engine continued the Porsche traditions of a boxer layout and air-cooling. The bore and stroke were respectively, giving a displacement of . The oversquare dimensions kept piston speeds low, and kept the engine narrow and as far out of the airflow on the sides of the car's tub as possible, although it was still wider than the 120° V6 and 90° V8s of the competition. A prototype engine was first started on a test-bench on 12 December 1960. That first 753 only produced (some sources say ). During the development of the 804, there were concerns about the readiness of the eight-cylinder engine, so the second chassis, 804-02, was modified to accept the air-cooled 1.5-liter four-cylinder boxer engine type 547 from the 787. That chassis was later converted back to