4G9x family

From Mitsipedia
Mitsubishi 4G94.jpg
Manufacturer Mitsubishi Motors
Configuration Inline 4
Cylinder block alloy Cast Iron
Cylinder head alloy Aluminum alloy
Valvetrain SOHC/DOHC

Mitsubishi's 4G9x family is a series of inline 4 cylinder engines ranging in size from 1.5 to 2.0 litres. They utilise a cast iron block with aluminum head and belt driven camshafts in single or double overhead form. As a small capacity engine it does not make use of balance shafts.

The 4G9x showcases Mitsubishi's advanced engine technology with some variations available with MIVEC variable valve timing and lift, Modulated Displacement cylinder deactivation, turbocharging and Gasoline Direct Injection (GDI). It has the distinction of being the first modern GDI engine developed.

As with most of Mitsubishi's modern engines, the 4G9x family can have numerous variations within the same engine model.


The 4G91 was the first engine in the family and is a 1.5 Litre engine displacing 1496cc. It has a 78.4mm x 77.5mm bore and stroke.

The DOHC fuel injected version used a 9.5:1 compression ratio was used in upper-level Japanese Lancer, Mirage and Mirage Astis and produced 84 kW at 6000rpm and 135 Nm at 5000rpm.

The only other version of the engine was a DOHC carburetted version outputting 71 kW at 6000 rpm and 126Nm at 3500 rpm.


In late 1991, Mitsubishi released its the 1.6 Litre 4G92. The engine used a slightly larger 81mm bore over the 4G91 with the same 77.5mm stroke for a 1597cc displacement.

A DOHC version of the engine with a high 11:1 compression ratio (requiring the use of premium unleaded) generating 107 kW at 7000 rpm and 149 Nm at 4500 rpm was used in the Japanese market Mirage RS and Super R.

In 1992, Mitsubishi released its first MIVEC engine with the 4G92 MIVEC. It is one of the most powerful non-turbocharged Mitsubishi four cylinders built using a 11:1 compression ratio with MIVEC variable valve timing and lift. Power increased to 129kW at 7500 rpm and 1467 Nm at 7000 rpm. It's famed for being a revvy engine. It was used in the Japanese market Lancer MR, Mirage Cyborg/VR and high-power 1994 and newer Mirage Asti.

Following the 4G92 MIVEC, Mitsubishi released a version with Modular Displacement - its cylinder deactivation technology which helps to conserve fuel. It was only available for a few years before being dumped.

Mitsubishi also built a more modest version of the engine with SOHC and a lower 10.0:1 compression ratio. The engine was produced in different variants depending upon the market and year.

The early 4G92 for the European market (until 2001) used camshafts with 20°/42° intake and 54°/2° exhaust valve timing (open/close) and produced 83 kW at 6000 rpm and 137Nm at 5000rpm [1]. Later European and General Export versions of the engine used a camshaft with 4°/58° intake and 52°/16° exhaust valve timing and produced up to 77 kW at 6000 rpm and 141 Nm at 4500 rpm [2].

In Australia, the 4G92 was only available as the General Export 4G92 SOHC in the CC Lancer where it produced 77kW at 6000 rpm and 134 Nm at 4500 rpm.


The 4G92P was the designation of the 4G92 used in Proton vehicles. In Australia, it was used in the Proton Satria, Persona and Wira XLi models and produced 83 kW at 6000 rpm and 137 Nm at 4000 rpm.


The 1.8 Litre 4G93 with it's longer 89mm stroke with the same 81mm bore as the 4G92 giving a displacement of 1834cc is the most varied of the engine family.

It first appeared in 1991 in the Japanese market RVR wagon with SOHC, fuel injection and a 9.5:1 compression ratio. It produced 88kW at 6000 rpm and 159 Nm at 4500 rpm, with the same engine later used in the Japanese Libero and the Australian CC-CE Lancer and Pajero iO.

Mitsubishi also released a high-performance version of the 4G93 using DOHC and a TD04 turbocharger with air-to-air intercooler with a 8.5:1 compression ratio to produce 143kW at 6000 rpm and 270 Nm at 3000 rpm. It required premium unleaded fuel and was released in the late 1991 Japanese market Lancer GSR and RS. It came to Australia in the CC Lancer GSR where it was detuned to run on standard unleaded and output 141kW at 6000rpm and 255Nm Nm at 3000rpm. Power was increased to 145 kW in the Australian Lancer from 1995.

A higher output version of the 4G93 Turbo was introduced in 1994 to the Japanese market Libero GT and Lancer GSR/RS and Mirage VR-X AWD where it was given a higher 9.0:1 compression ratio to produce 151 kW at 6000 rpm and 275 Nm at 3000 rpm. Later incarnations of the Libero GT were upgraded to 158kW and 284 Nm.

A SOHC electonic carburetted 4G93 appeared in the base-model Emeraude, Eterna and Galant producing 81 kW at 6000 rpm and 154 Nm at 3000rpm.

Mitsubishi produced a non-turbo fuel injected DOHC 4G93 in it's Japanese Libero Vienta II, Eterna Visage S and Galant with a 9.5:1 compression ratio producing 103kW at 65000 rpm and 167 Nm at 5000 rpm.

In August 1996, Mitsubishi broke new ground when it released the first modern Gasoline Direct Injection engine with the 4G93.

It was initially released in the Japanese Legnum and mid-spec Galant with DOHC and an increased 12.0:1 compression ratio. Requiring premium unleaded, the engine output 110 kW at 6500 rpm and 178 Nm at 5000 rpm. Fuel consumption is reputed to be as low as 5.3 litres/100 Km [3] thanks to the ultra lean air-fuel ratios made possible by the GDI system. In 1997, the 4G93 GDI appeared in Europe under the bonnet of the Carisma and Volvo S40/V40. From 1997 onwards, power and torque slid to 103 kW at 6000 rpm and 181 Nm at 3750 rpm in all 4G93 DOHC GDI engines.

In 1998, the Japanese Pajero iO was the next model to come with the 4G93 GDI with power again slipping, this time to 96 kW at 5500 rpm and 181 Nm at 3500 rpm (the same specfications later appeared in the 2000 Lancer Cedia) 1998 also saw the introduction of 'quiet/low exhaust' specification Galant and Legnums which reduced power to 99 kW at 6000 rpm and 177 Nm at 3750 rpm. Power in standard spec vehicles remained the same.

In 2000, Mitsubishi released its first GDI Turbo in the Pajero iO TR. Using a high (for turbo) 10.0:1 compression ratio the engine also used an air-to-air intercooler to produce 118 kW at 5200 rpm and 220 Nm at 3500 rpm. The engine later appeared (mounted east-west) in the Lancer Cedia wagon and Dion van to produce a healthier 121 kW at 5500 rpm and 220 Nm at 3500 rpm.


Based upon the non-turbo 4G93 DOHC, the 4G93P was an engine used in Proton vehicles. In Australia it was used in the Proton Satria GTi with a 10.5:1 compression ratio and requiring premium unleaded fuel. It output 103 kW at 6000 rpm and 164 Nm at 5500 rpm. Earlier versions used Mitsubishi ECUs with Proton moving to a Siemens VDO ECU and MAP sensor from 2003, which reportedly produced less power and felt less responsive [4].


In 2000, Mistubishi released a 2.0 Litre engine with a 81.5x95.8mm bore and stroke displacing 1999cc.

In the Japanese Aspire, Legnum, Galant, Dion and Pajero iO it came with DOHC, GDI and a 10.6:1 compression ratio to produce 107kW at 5700 rpm and 191 Nm at 3750 rpm in the Aspire, Legnum and Galant and 100kW at 5500 rpm and 191 Nm at 3500 rpm in the Dion and Pajero iO.

From 2002 a SOHC non-GDI version of the 4G94 was produced. It appeared in Australia and output 95 kW at 5500 rpm and 177 Nm at 4500 rpm in the Pajero iO and 92 kW at 5500 rpm and 173 Nm at 4250 rpm in the CG and CH Lancer.

3 cylinder
3A9x 3A90 3A91 3A92
4 cylinder
Neptune 4G41 4G42
Orion 4G11 4G12 4G13 4G15 4G17 4G18 4G19 G4ED
Sirius 4G61 4G62 4G63 4G64 4G67 4G69
Astron 4G51 4G52 4G53 4G54
Astron II Original Revised
Saturn 4G30 4G31 4G32 4G33 4G37
4G9x 4G91 4G92 4G93 4G94
4A9x 4A90 4A91 4A92
4B1x 4B10 4B11 4B11T 4B12
Inline 6
Saturn 6 6G34
6G7x 6G71 6G72 SOHC 12v 6G72 SOHC 24v 6G72 DOHC Early 6G74 Late 6G74 Ralliart 6G74 6G75
6A1x 6A10 6A11 6A12 6A13
6B3x 6B31
8A80 8A80