The FIRE (for "Fully Integrated Robotised Engine") is a series of automobile engines from Fiat Powertrain Technologies, built in FCA's Termoli, Betim and also in Dundee, MI (only in 1.4 Multiair versions) plants. It was designed by Italian design firm Rodolfo Bonetto. It is constructed by robot assembly plants ("Robogate") to reduce costs.

The FIRE series replaced the old Fiat 100 series Overhead valve engines in the mid-1980s. Mechanically, they are simple inline-four engines with five main bearings crankshaft and overhead cam heads.

Since 1985, it has been constructed in different versions. Displacements range from 0.8 to 1.4 L; 46.9 to 83.5 cu in (769 to 1,368 cc). In addition to the 8 valve versions, there are "Super-FIRE" 1.2 and 1.4 L; 75.8 and 83.5 cu in (1,242 and 1,368 cc) 16 valve versions.

The "Super-FIRE" which uses 16 valves and is available in 1.0 L; 61.0 cu in (999 cc) (Brazil) and 1.2 L; 75.8 cu in (1,242 cc) (Brazil & Europe) displacements.

The 1.4 L; 83.5 cu in (1,368 cc) variation introduced in 2003 is available in both 8 and 16 valves. In 2005 Fiat introduced a version of the 16v incorporating port deactivation (PDA) and EGR. This unit is frequently referred to as the "StarJet" engine. One year later, a turbocharged variety of the StarJet was introduced under the name "T-Jet", and a MultiAir (adding electro-hydraulic intake valve driving, with variable timing, lift and profile) version was added in 2009, available in either naturally aspirated and turbocharged forms. It reached 190 PS on the Abarth 695 Biposto.

The FIRE was originally a carburetor engine, and later progressed to single-point injection (SPI), then to multi-point fuel injection (MPI), using sequential multi-port fuel injection (SMPI) today. It is now used in the 750 Formula in a slightly modified state.

Brazilian production started in 2000 with the "Super-FIRE" 1.2 16V (80 PS), was extended until 2006 with 1.0 8V (54 PS), 1.0 16V (69 PS), 1.2 8V (66 PS) and 1.4 8V (80 PS). By 2016, the two "last Super-FIRE" being produced in Brazil were the reworked (New pistons and crankshaft) 1.0 8V (77 PS) and the 1.4 8V VVT (90 PS), both running on petrol or ethanol fuels.

Starting in 2016, it is being replaced by the GSE (FireFly) engine family.