The first models to reach the US shores were 1975 models equipped with the old pushrod B20F engine, but most other markets, as well as the US '76 models, got the new overhead cam B21F motor. An all-aluminum 2.7 liter V6, the B27F, was added for the '77 model year.
The 240 incorporated many improvements over its predecessor, the Volvo 140, including:
As is usual for Volvo, incremental improvements were made almost every year of the production run. One of the major improvements was the introduction of the oxygen sensor in 1977 ('78 models), which Volvo called the Lambda Sond and developed in conjuction with Bosch. It basically added a feedback loop to the K-Jetronic fuel injection system already in use, which allowed fine-tuning of the mixture and therefore superior emissions, drivability and economy.
The original Volvo nomenclature consisted of three numbers: the first letter indicated the model (series), the second the number of cylinders, and the third the number of doors. So a 265 would be a six-cylinder wagon (5 doors). This nomenclature was replaced in the US in '81 by letters, which in turn was superceded with every model being called a 240.
About one-third of all 240's sold were station wagons, called 245's in Volvo lingo. They could be outfitted with a rear-facing foldable jumpseat in the passenger area, making the wagon a 7-passenger vehicle. The jumpseat of course came with 3-point seatbelts and wagons were designed to have a reinforced floor section to protect the occupants of the jumpseat in the event of a rear-end collision.
Special 240 models: