GWM Tank 300 Engine Oil Guide: Grade, Capacity and the Dipstick Rule
The GWM Tank 300 with the E20CB petrol engine takes 5.5 litres when the oil and filter are both changed, or 5.0 litres for an oil-only change. Under API standards, use a fully synthetic SN oil in 5W-30 where ambient temperature is minus 30 degrees Celsius or above, and 0W-30 below that. Under ACEA standards, use C2 5W-30 above minus 30 degrees, or C2 0W-30 below. Check the level on flat ground with the engine warm, the power supply switched off, and after a 10 minute wait.
The oil specification, in plain terms
Two standards, four options, and only one of them applies to you.
If you buy to API standards:
- Quality grade SN, fully synthetic
- 5W-30 viscosity when ambient temperature is minus 30 degrees or higher
- 0W-30 viscosity for colder conditions
If you buy to ACEA standards:
- C2 5W-30 fully synthetic above minus 30 degrees
- C2 0W-30 fully synthetic below that
For most owners in temperate and hot climates, that means a fully synthetic 5W-30. The 0W-30 option exists for genuine alpine conditions, not for a cold morning.
Oil quality is not a place to economise. Insufficient or deteriorated oil causes poor lubrication of rotating parts, which leads to sintering and engine damage.
Capacity and fluid table
| Attribute | Oil and filter change | Oil-only change | Front differential | Rear differential | Transfer case |
|---|---|---|---|---|---|
| Fluid type | Fully synthetic engine oil | Fully synthetic engine oil | DUAL 9 FE 75W-90 | DUAL 9 FE 75W-90 | Dexron III |
| Measurement (capacity in litres) | 5.5 plus or minus 0.1 | 5.0 plus or minus 0.1 | 1.05 plus or minus 0.05 | 2.4 plus or minus 0.1 | 1.5 plus or minus 0.05 |
| Owner-checkable | Yes, by dipstick | Yes, by dipstick | No | No | No |
| Typical service item | Every service | Every service | Scheduled interval | Scheduled interval | Scheduled interval |
These are reference values. Always fill to the dipstick reading rather than to a number.
How to check the level properly
Getting this wrong is why people either overfill or top up an engine that was already fine.
- Park on flat ground. A slope skews the reading in both directions.
- Warm the engine to normal water temperature.
- Switch the power supply to OFF mode.
- Wait 10 minutes before pulling the dipstick. This is the step most people skip.
- Read the level. It should sit between the minimum and maximum marks.
- If it is close to or below the minimum, add oil until it sits between the two marks.
The dipstick shape varies depending on the engine, so read the marks on your own stick rather than assuming a familiar pattern.
The one-third rule before a steep climb
This is the detail almost nobody outside the manual knows.
Before the vehicle climbs an extreme slope, the oil level must not be less than one third of the dipstick scale between the upper and lower limits. If it is, add oil before you attempt the climb.
The reason is straightforward. On a steep angle, oil pools away from the pickup. A level that is perfectly acceptable on flat ground can leave the pump drawing air on a long, steep ascent.
If you spend weekends in low range, check the dipstick before the trip, not after.
Filling without causing damage
- Open the filler cap and pour slowly to avoid spillage
- Remove any overflow immediately, because spilled oil can damage components in the engine compartment
- Do not overfill. Excessive oil is a problem in its own right, not a safety margin
Oil additives are not needed
The manual is direct on this: the vehicle does not require any oil additives, and additives cannot improve engine performance or durability.
If a workshop offers a bottle of something to pour in at the end of a service, it is not doing anything the oil is not already meant to do.
Why the level drops even with normal driving
A falling oil level is not automatically a leak.
Engine oil lubricates and cools. A certain amount of the oil lubricating the pistons and valves ends up in the combustion chamber and is burned. The level goes down over time even when everything is working correctly, and how fast depends on driving conditions.
This is exactly why regular checks matter more than an annual glance. If the low oil pressure warning light appears, our warning lights guide covers the correct response, which starts with stopping.
Safety before you open the bonnet
Three straightforward rules.
- Keep clear of rotating parts. With the engine running, belts and fans can catch hands, clothing and tools.
- Expect heat. Take care to prevent burns when checking or adding oil.
- Store oil responsibly. Oil that leaks into the ground or reaches waterways causes environmental pollution.
Questions owners actually ask
"Can I use 5W-40 instead of 5W-30?" The specified viscosity grades are 5W-30 and 0W-30 depending on temperature. Straying from a specification that the engine was designed around is a risk taken for no benefit.
"Do I need to change the oil more often for off-road use?" Off-road work counts as severe duty, and several service items shorten under those conditions. Our break-in and service guide covers the standard intervals and where severe duty changes them.
"The level reads high right after a drive. Should I drain some?" Check it again properly: flat ground, power off, 10 minutes of settling. Draining based on a hot, immediate reading is how correct levels become low ones.