Mitsubishi Sirius Engine: The 4G6 and 4D6 Family Behind the Evo

The Mitsubishi Sirius, also written 4G6 or 4D6, is one of the four inline-four families that Mitsubishi built alongside Astron, Orion and Saturn. Its petrol units supplied the company's performance cars, most famously the turbocharged 4G63 that powered the Lancer Evolution, while its diesels served the mainstream passenger range.

Where does the Sirius sit in Mitsubishi's engine line-up?

Sirius is one of four inline-four series, alongside Astron, Orion and Saturn. The 4G6 petrol engines were the favoured performance variant, and the 4D6 diesels supplemented the larger 4D5 engines. Hyundai also built versions of the design under its own G4 codes. In Hyundai and Kia guise the engine carried the G4CP, G4JS and G4JP codes, and it fitted models such as the Sonata, Santa Fe, Trajet and Optima.

The 4G6 designation covered a wide range of capacities, from the 1.6 litre 4G61 to the 2.4 litre 4G64 and 4G69. The 4D6 diesels had a bore pitch of 93 mm and were used in most Mitsubishi diesel passenger cars through the eighties and early nineties.

One Mitsubishi inline-four family that ran from a 1.6 litre economy unit to the turbocharged 4G63 that carried the Lancer Evolution.

How did the 4G61 1.6 litre engine work?

The 4G61 displaces 1,595 cc with an 82.3 mm bore and a 75 mm stroke. It was always a DOHC 16-valve unit with either multi-point or electronic fuel injection, and unlike the other Sirius motors it has no balance shafts. A turbocharged version went into the Mirage and the Lancer.

Naturally aspirated, the 4G61 managed 105 hp (78 kW; 106 PS) at 6100 rpm. Turbo output varied by market. The US and Canadian 4G61T reached 135 hp (101 kW; 137 PS) at 6000 rpm, with 191 N m (141 lbf-ft) of torque at 3000 rpm, while early Japanese cars managed 145 PS (107 kW; 143 hp) at 6000 rpm, rising to 160 PS (118 kW; 158 hp) in later cars.

Applications ran from the 1988 to 1992 Mitsubishi Mirage and Colt, through the Dodge and Plymouth versions of the Colt and the Eagle Summit, to the 1992 to 1995 Hyundai Elantra.

Why was the 4G63 so important?

The 4G63 is the 2.0 litre engine that made the Sirius famous. Its turbocharged form powered the Lancer Evolution in World Rally Championship competition, and its DOHC layout later gained the MIVEC variable valve timing system. It was built in SOHC and DOHC form, both naturally aspirated and turbocharged, across roughly two decades.

The turbocharged 4G63T, first seen in the 1980 Lancer EX 2000 Turbo, carried Mitsubishi through its rally years. It also powered the Galant VR-4, the Carisma GT and the Lancer WRC04, and it was the engine in the Lancer Evolution when Tommi Makinen won four consecutive WRC championships in his Lancer.

The DOHC version arrived in 1987 in the Japanese market Galant, in turbocharged or naturally aspirated form. Diamond Star Motors, a joint venture between Mitsubishi and Chrysler, brought the turbocharged intercooled DOHC to the United States in 1989 through the Eclipse, Eagle Talon and Plymouth Laser.

A carbureted SOHC eight-valve version, engine code G63B, went into the L200, Strada, Mighty Max and Dodge Ram 50 pickups from the eighties until the mid-nineties. In European trim in 1989 it produced 92 hp (69 kW; 93 PS) at 5500 rpm.

Output grew steadily over the years. The 2003 US Lancer Evolution made 202 kW (271 bhp; 275 PS) at 6500 rpm and 370 N m (273 lb-ft) at 3500 rpm, from a cast-iron block with an aluminium DOHC head, multi-point injection, four valves per cylinder and forged steel connecting rods.

The Evolution IX gained MIVEC and a revised turbocharger, along with extended-reach spark plugs and two-piece rings. The early engines used six bolts to secure the flywheel, from 1990 to April 1992, and seven from May 1992 to 2006.

The FQ400, a UK-market Evo, carried a 400 bhp (298 kW; 406 PS) version of the Sirius, which made it the most powerful car Mitsubishi ever sold.

A SOHC 16-valve turbocharged version, the 4G63S4T, is built by SAME in Shenyang. It has a peak power of 130 kW (174 hp; 177 PS) and a TD04 turbocharger, and it is rated at 140 kW (188 hp; 190 PS) in some applications.

What did the 4G62 and 4G64 cover?

The 4G62 is a 1.8 litre SOHC eight-valve engine for longitudinal rear-wheel drive and all-wheel drive use. It came in carburettor form, with multi-point fuel injection, or as the ECI Turbo. Its 80.6 mm bore and 88 mm stroke gave 1,795 cc, and the ECI Turbo version powered the Lancer EX 1800GSR and 1800GT, as well as the Cordia GSR.

The 4G64 is the larger 2.4 litre member, at 2,351 cc with an 86.5 mm bore and 100 mm stroke. Early models were SOHC eight-valve units, and later 16-valve SOHC and DOHC versions followed, all with multi-point injection. The SOHC eight-valve 4G64 is a non-interference design, while the 16-valve versions are interference engines.

Output varied with the application. In the Mitsubishi L200 the 4G64 made 155 hp (116 kW; 157 PS) at 5250 rpm, while the Chrysler Sebring and Stratus version made 152 hp (113 kW; 154 PS) at 5500 rpm, with fracture-split forged powder metal connecting rods. From March 1996 an LPG version producing 115 hp (86 kW; 117 PS) at 5000 rpm was available in the Mitsubishi Canter.

The 4G64 was very popular in China, where Shenyang Aerospace Mitsubishi Motors assembled it from 1998 onward. It powered the Changfeng Liebao, a range of cars based on the Pajero V20 that ran from 2002 to 2021.

How did the 4D65 and 4D68 diesels differ?

The 4D65 Sirius Diesel had the same dimensions as the 4G62, at 1,795 cc. It was developed for transverse fitting in front-wheel drive cars, and its cast-iron block carried balance shafts, which was unusual for a diesel of its time.

The 4D65 came naturally aspirated or turbocharged with an air-to-air intercooler, and Mitsubishi used it widely in diesel models. Its 1.8 litre turbo figures were comparable with those of the larger 2.3 litre 4D55, with more low-down torque and smoother running.

The 4D68 was a 2.0 litre diesel of 1,998 cc, with an 82.7 mm bore, a 93 mm stroke and a compression ratio of 22.4:1. It used a swirl chamber and an electronic distributor-type injection pump with a turbocharger, and it replaced the 4D65 as Mitsubishi's go-to diesel. It used roller-type rocker arms and single-type exhaust gas recirculation. It went into the Mirage, Colt, Lancer, Chariot and RVR models through the 1990s, and into the Triton and L200 pickups in 2007 and 2008.

What were the 4G67 and 4G69 engines?

The 4G67 is a 1.8 litre 16-valve DOHC engine of 1,836 cc, measuring 81.5 mm by 88 mm. It was used in the 1989 to 1992 Colt and Lancer 1.8 GTI and the Galant, and Hyundai used it in the Elantra from 1993 to 1995 under the name G4CN.

The 4G69 is a 2.4 litre of 2,378 cc, measuring 87 mm by 100 mm. It produced 120 kW (161 hp; 163 PS) at 5750 rpm, with 219 N m (162 lb-ft) of torque at 3500 rpm. It has MIVEC variable valve timing, an aluminium SOHC head and a cast aluminium intake manifold, and it was built in Shiga, Japan and Shenyang, China.

Mitsubishi ceased development and production of the Sirius engine after the 2012 model year. Its Chinese joint venture, Shenyang Aerospace Mitsubishi Motors Engine Manufacturing, is now the only maker of the 4G69, which it has updated with an aluminium block and a timing chain for Chinese manufacturers.

How did the 4K series replace the Sirius?

The 4K1 series reused the 4G6 shortblock with a new SOHC 16-valve head, including VVL and MIVEC technology. In 2017 Mitsubishi launched the 4K2 family with a DOHC head, and in 2022 the 4K3 series introduced a turbocharged direct injection engine. All of them were built by SAME in Shenyang.

The 4K10 is a destroked 4G63 shortblock of 1,798 cc, with 100 kW (134 hp; 136 PS) at 6000 rpm. The 4K11 has 1,997 cc and 110 kW (148 hp; 150 PS) at 6000 rpm, while the 4K12 uses the 4G69 shortblock for 2,378 cc and 120 kW (161 hp; 163 PS) at 6000 rpm. The 4K10 has no balance shaft, the 4K11 offers one as an option, and the 4K12 fits one as standard.

The 4K2 family includes the turbocharged 4K20, rated at 128 kW (172 hp; 174 PS) at 5500 rpm, the 4K21, which reaches 150 kW (201 hp; 204 PS) at 5600 rpm in turbo form, and the 4K22, at 160 kW (215 hp; 218 PS) at 5600 rpm. The 4K31 of 2022 is a 1,997 cc turbocharged direct injection unit with 168 kW (225 hp; 228 PS) and 360 N m of torque.

Which Sirius variants were fitted where?

The table lists the main Sirius variants with their capacity, valvetrain, published output and example applications. Where no output figure is published, the table shows the entry as not given.

Why do Sirius engines still matter?

The Sirius family matters because one basic design spanned rally cars, economy hatchbacks, diesel passenger cars and Chinese pickups. The 4G63 is the best-known member, but the 4G69 and the 4K series show how the shortblocks kept finding new uses long after the first 4G61 was built. That reuse of shortblocks is the thread that ties the 4G, 4D and 4K designs together.

Its Chinese chapter is significant as well. Shenyang Aerospace Mitsubishi Motors continues to build 4G69 and 4K-series engines long after Mitsubishi ceased Sirius production, which keeps the family alive in a different market from the one that created it.

The family's motorsport record, from rally stages to the title-winning Lancer Evolution, is the strongest argument for its place in history.