The Mitsubishi Orion or 4G1 engine is a series of inline-four internal combustion engines introduced by Mitsubishi Motors in around 1977, along with the Astron, Sirius, and Saturn. It was first introduced in the Colt and Colt-derived models in 1978. Displacement ranges from 1244 to 1584 cc.

4G11

The 4G11 displaces 1244 cc with a bore and stroke of 69.5x82 mm. Applications:

4G12

The 4G12 (also known as the G11B) displaces 1410 cc with a bore and stroke of 74x82 mm. 4G12 was the first to feature Mitsubishi's MD (modulated displacement) technology, a form of variable displacement which shut off two cylinders during light load and at low speeds. The 4G12 was not offered by Mitsubishi with fuel injection. This engine is fairly outdated compared to its counterparts that were used in the later Lancers. Applications:

4G12T

This is the turbocharged version of the 4G12, uses a TC-04 turbocharger from Mitsubishi Heavy Industries. The diameter of the blades in this charger is rather small, at 49 mm, and it spins at 90,000 rpm to provide 0.53 bar of boost. This increased power and torque by about 30 and 25 percent respectively. The Japanese-specification version of this engine produces 105 PS at 5,500 rpm and 15.5 kgm of torque at 3,000 rpm.

4G13

The SOHC, 12 & 16 valve 4G13 displaces 1298 cc and produces 75-85 PS with a bore and stroke of 71x82 mm. In the Gulf Countries, 90 PS gross at 6000 rpm is claimed on the mitsubishi lancer CB1. The 4G13 engine has been produced by Dongan Mitsubishi Motors Engine Manufacturing, in Harbin, China since September 1998.

4G15

The SOHC 4G15 displaces 1468 cc with a bore and stroke of 75.5x82 mm. A version of the 4G15 was produced with gasoline multi-port fuel injection. It has approximately 94 hp-metric on the 1993 Mirage model. The DOHC 4G15 produces 109 hp with 137 Nm of torque. Another DOHC version was combined with GDI fuel injection and delivers 100 hp-metric and 137 Nm of torque. A DOHC MIVEC turbo variant of the engine is also still in production to date (4G15T), serving in the Mitsubishi Colt series, offering 165 hp-metric on the latest Colt Version-R (with exhaust enhancement). The most powerful version of this engine is found in the Colt CZT Ralliart (special model in Switzerland) with a total output of 197 hp. When installed in the Smart ForFour Brabus, the engine received the Mercedes-Benz engine code M122 E15 AL. The 4G15 is known as one of the longest living Japanese engines ever produced where new variants of the engine are still being produced and used in Chinese cars since 2005. The 4G15 engine has been produced by Dongan Mitsubishi Motors Engine Manufacturing in Harbin, China. And also the new engines have been produced by GAC Mitsubishi Motors, a joint venture from the Hunan province in southern China, since April 2017.

SOHC 8-valve (4G15)

This version of the 4G15 is a single overhead camshaft (SOHC) 8-valve, carburetor type engine. It is an in-line four with a compact type combustion chamber. The engine's advertised power was 77 PS (DIN) and 127 Nm of torque. The engine is an analogue of the Mitsubishi G15B in terms of the engine mechanical specifications except for the valve timing. The G13B is also equipped with jet valves and jet springs. SPECIFICATIONS: Total displacement: 1468 cc Bore x Stroke: 75.5x82 mm Compression Ratio: 9.4:1

SOHC 12-valve (4G15)

A 12-valve version (two intake and one exhausts per cylinder) of the 1468 cc 4G15 engine. It entered production in 1989, for the third generation Mitsubishi Mirage/Lancer. It was available with a carburettor or fuel injection, producing 85 or in Japanese market trim at the time of introduction. Later, a natural gas-powered version was added and in 1991 a new lean-burn technology called "Mitsubishi Vertical Vortex" (MVV) was introduced on this engine.

4G16

The 4G16 displaces 1198 cc from a 68.2x82 mm bore and stroke. This engine was mainly offered in European markets, where it suited local tax regulations. Applications:

4G17

The 4G17 displaces 1343 cc. It is a SOHC 12-valve engine. Bore and stroke is 72.2x82 mm. Output of a carbureted version is 78 PS at 6,000 rpm and 10.9 kgm of torque at 3,500 rpm. Applications:

4G18

The SOHC 4G18 displaces 1584 cc with a bore and stroke of 76x87.3 mm. It is a 4-valve per cylinder engine, which produces from 98 PS to 110 PS with 150 Nm (European specifications). It uses a COP (Coil-On-Plug, also known as Plug-top coil) ignition rely on one coil to fire two cylinders, one of which was by spark plug wire. The 4G18 engine has been produced by Dongan Mitsubishi Motors Engine Manufacturing, in Harbin, China since April 2010.

4G19

The DOHC MIVEC 4G19 displaces 1.3–litres and features four valves per cylinder. It produces 90 PS at 5,600 rpm and 121 Nm of torque at 4,250 rpm. It was introduced in 2002, powering the then-new Mitsubishi Colt. Applications: