The Volvo P1800 is a sports car that was manufactured by Volvo Cars between 1961 and 1973.
The engine was the B18 (B for the Swedish word for gasoline: Bensin; 18 for 1800 cc displacement) with dual SUcarburettors, producing 100 hp (75 kW). This variant (named B18B) had a higher compression ratio than the slightly less powerful twin-carb B18D used in the contemporary Amazon 122S, as well as a different camshaft. The 'new' B18 was actually developed from the existing B36 V8 engine used in Volvo trucks at the time. This cut production costs, as well as furnishing the P1800 with a strong engine boasting five main crankshaftbearings. The B18 was matched with the new and more robust M40manualgearbox through 1963. From 1963 to 1972 the M41 gearbox with electrically actuated overdrive was a popular option. Two overdrive types were used, the D-Type through 1969, and the J-type through 1973. The J-type had a slightly shorter ratio of 0.797:1 as opposed to 0.756:1 for the D-type. The overdrive effectively gave the 1800 series a fifth gear, for improved fuel efficiency and decreased drivetrain wear. Cars without overdrive had a numerically lower-ratio differential, which had the interesting effect of giving them a somewhat higher top speed (just under 120 mph (193 km/h)) than the more popular overdrive models. This was because the non-overdrive cars could reach the engine's redline in top gear, while the overdrive-equipped cars could not, giving them a top speed of roughly 110 mph (177 km/h).