6B3x family

From Mitsipedia
6B31 Pallet.jpg
Manufacturer Mitsubishi Motors
Configuration V6
Cylinder block alloy Die-cast aluminum
Cylinder head alloy Die-cast aluminum
Valvetrain Belt-driven SOHC with 24 valves and MIVEC
Predecessor 6G7x

The 6B3x family of engines are 60 degree angle V6 engines produced by Mitsubishi in Shiga, Japan. It is an all-alloy design with single overhead camshafts driven by a belt. Valves are actuated by roller rockers with automatic lash adjusters on the exhaust valves only.

The engine was designed primarily for use in the North American Second Generation Outlander and is designed to produce plentiful amounts of torque in the low and medium rev range as demanded by an SUV. It achieves this by using MIVEC for valve timing and lift and a variable length inlet runner manifold.

The weight of the engine has been reduced by the use of an aluminum block, heads and oil pan along with resin rocker covers, resin intake manifold and a guideless dipstick to reduce weight by 25 Kg compared to the 3.0L 6G72. Mitsubishi claims the engine is only 5Kg heavier than the four cylinder engine used in the First Generation Outlander.

So far only the 3.0 Litre 6B31 has been released.

The engine was the last in Mitsubishi's early to mid 2000s 'engine renovation program' following the 4A9x, 4B1x and 3B2x.[1]


The 6B31 is a 3.0 litre V6 engine. It uses 24-valve single overhead camshafts with MIVEC. It displaces 2998 cc using a 87.6 mm x 82.9 mm bore and stroke. It has a 9.5:1 compression ratio and produces 162 kW at 6250 rpm and 276 Nm at 4000 rpm. Compared to the 6G72 24-valve SOHC as used in the North American Eclipse GTS the engine weighs 25 Kg less and outputs 7 kW more power but 2 Nm less torque. The engine has a relatively flat torque curve, with 90% of the engine's torque available from just 2000 rpm.

In Australia it has been used in the ZG and ZH Outlander.


Displacement 2998 cc (3.0 Litres)
Bore 87.6mm
Stroke 82.9mm
Compression Ratio 9.5:1
MIVEC Switch 4750 rpm
Intake Runner Switch 3600 rpm
Output 162 kW @ 6250 rpm, 276 Nm @ 4000 rpm



  1. Newly Developed V6 MIVEC Engine, Mitsubishi Technical Review, 2007/19 (archived)
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