Mitsubishi MTX13 & MTX15: which engine oil and fluids?

Looking for the right Mitsubishi MTX15 engine oil, or not sure which oil belongs in your MTX13? In this guide we've listed all the fluids for the Mitsubishi MTX13D and MTX15D: engine oil, transmission and hydraulic oil, front axle oil and coolant — including the capacities from the original manual and a modern translation of the oil specification. That way you can service with confidence, without guessing.

Suitable for the entire series: Mitsubishi MTX13D and MTX15D.

Mitsubishi MTX13 & MTX15: all capacities in one table

These are the fill quantities according to the original manual. Handy to keep close by when servicing:

In addition, the machine has 8 lubrication points that need greasing every 50 hours. You'll find the full intervals in the maintenance schedule for the MTX13 and MTX15.

Mitsubishi MTX13 & MTX15 engine oil: the specification and the modern translation

The manual specifies diesel-grade API CC or higher engine oil, with viscosity depending on outdoor temperature: below approximately -10°C a 10W-30, around 0–20°C SAE20, and above 20°C SAE30. These were common single-grade oils at the time.

The modern translation is simpler: a 15W40 of API CD quality covers virtually all Dutch conditions and comfortably meets the original specification. Only during a harsh winter with prolonged frost is a 10W-30 the better choice for easier cold starting. A suitable oil is the Engine Oil 15W40 5L (SKU-15W40).

The engine oil capacity is 2.9 litres. Change it for the first time after 50 operating hours and then every 100 hours, each time together with a new oil filter. You can find out which filters you need in the overview of all filters for the MTX13 and MTX15.

Mitsubishi MTX13 & MTX15 and the STOU story: why the same oil is used everywhere

Come across a machine where the engine, gearbox and front axle all contain exactly the same oil? That's not sloppiness. Mitsubishi used to sell its own "Multi STOU" oil (10W-30), which could be used in both the engine and the transmission. Many owners therefore filled everything with a single oil. This is still possible with a genuine STOU oil, but nowadays it's more common to choose the best-suited oil per system: 15W40 for the engine, GL-4 UTTO for the transmission and 80W90 for the front axle.

Mitsubishi MTX13 & MTX15 transmission and hydraulic oil: one housing, one oil

Important to know: on this series, the gearbox and hydraulics share one housing with a combined 12 litres of oil. This means the hydraulic pump draws in the same oil in which the gears turn. Contaminated or old transmission oil therefore directly leads to lift problems: a lift that raises slowly, no longer rises, or makes strange noises. You can read more about this in our article on the hydraulics and PTO of the MTX13 and MTX15.

The manual specifies API GL-3 SAE#80 or higher; the modern equivalent is a GL-4 UTTO oil specially made for combined transmission/hydraulic systems, such as the Transmission/Hydraulic Oil GL-4 UTTO 10L (SKU-15W402). Change it for the first time after 100 hours and then every 200 hours; replace the hydraulic filter for the first time after 100 hours and then every 300 hours.

Mitsubishi MTX13 & MTX15 front axle oil: 2.5 litres 80W90 GL-4

The driven front axle has its own 2.5-litre housing. Here too, GL-3 SAE#80 or higher was originally specified; nowadays an 80W90 GL-4 is used, such as the Front Axle Oil 80W90 GL-4 4L (SKU-80W90). The interval is the same as for the transmission: first time after 100 hours, then every 200 hours. The front axle is often forgotten — milky or jet-black oil when draining tells you why this interval exists.

Mitsubishi MTX13 & MTX15 coolant: 4 litres, antifreeze at the right strength

The cooling system holds 4.0 litres. Use a coolant that can withstand severe frost, such as the Coolant -40°C 5L (SKU-125001). Don't know the machine's history, or do you see rust-coloured coolant? Then first flush the system with a cleaner such as the Radiator Flush 250ml (SKU-125007) before filling with fresh coolant. This prevents old deposits from continuing to burden the radiator and water pump.

Mitsubishi MTX13 & MTX15 servicing: practical tips

A few practical tips for a clean service:

• Drain the engine oil while warm: run the engine for a few minutes first, so dirt is carried out more effectively.
• Replace the drain plug's sealing ring every time — a leaking plug is a waste of your fresh oil.
• Always change the oil and filter together; a full filter immediately contaminates fresh oil again.
• After test running, check the level again and check for leaks around the plug and filter.