Petrol in a Diesel Mercedes ML? Start With the Tank
Once you have put petrol in a diesel Mercedes ML, the size of its fuel tank is among the first things to know, since it determines how much of what is in there is now petrol. We give the tank on every version of the Mercedes ML that we have figures for on this page, together with the motors it came with.
The guidance does not change with the figure once it has happened. Ring Petrol in Diesel with the engine kept off. We will come to you to drain it right where it is.
Version by version: Mercedes ML fuel tank capacity
Versions of the Mercedes ML differ, so the diesel tank takes anything from 70 to 95 litres according to yours.
Our figures place the largest tank on the ML 420 CDI and the smallest on the ML 400 CDI.
By comparison, the tank on the ML 350 BlueTEC 4-MATIC is 95 litres.
For the ML 320 CDI, the figure is 95 litres.
| Version | Fuel tank |
|---|---|
| Mercedes ML 250 Bluetec 4Matic | 70 litres |
| Mercedes ML 270 CDI | 70 litres |
| Mercedes ML 280 CDI | 95 litres |
| Mercedes ML 300 CDI 4-MATIC | 95 litres |
| Mercedes ML 320 CDI | 95 litres |
| Mercedes ML 350 BlueTEC 4-MATIC | 95 litres |
| Mercedes ML 350 Bluetec 4Matic | 70 litres |
| Mercedes ML 350 CDI 4-MATIC | 95 litres |
| Mercedes ML 400 CDI | 70 litres |
| Mercedes ML 420 CDI | 95 litres |
| Mercedes ML 450 CDI 4-MATIC | 95 litres |
A few litres of wrong fuel in your Mercedes ML, and what they mean
The proportion of petrol rests on how full your tank was before you refuelled. That's because wrong fuel in your Mercedes ML blends with whatever diesel was still in it. When a couple of litres of unleaded are put into a tank running near empty, they form a far larger share of what your engine would draw. Added to a nearly full tank of up to 95 litres, the same amount is only a minor share of the whole.
People commonly wonder how much petrol is too much. The more useful thing to find out is whether your engine has been run, as starting it is what carries the blend from your tank and through your pump and the fuel injectors.
Having it drained is the right option no matter what the share is. If the amount is small, your ML generally needs nothing more than that.
Engines used in the diesel ML
Your engine in your ML is given in the version name on the badge. Check it before you call.
The badges on all diesel versions of the ML within our data are CDI and BlueTEC.
The ML 350 Bluetec 4Matic wears the BlueTEC badge, while the badge seen on more versions than any other is CDI.
When you are not sure which version you drive, ring all the same and we'll work it out with you.
Tank size and AdBlue in a diesel Mercedes ML
Fuel tank size plays out differently with AdBlue. The fuel pump draws its fuel from the bottom of the tank, and that's where AdBlue settles, and so even a tiny amount gets into your fuel line. If you have AdBlue in a diesel Mercedes ML, your diesel surrounding it does not dilute it, as AdBlue is mostly water and doesn't mix with diesel.
As the water in AdBlue dries out, the urea left behind forms crystals in your lines and the filter and corrodes the metalwork around it, and AdBlue doesn't burn or give your pump any lubrication either.
The filler for AdBlue, on diesel cars that have it, commonly shares a flap with the diesel one and leads to a separate tank. Where your ML has an AdBlue filler, its cap is normally blue and takes a slimmer pump nozzle than the diesel one.
What a fuel drain on your Mercedes ML involves
Done where the car is standing, a fuel drain on your Mercedes ML empties the entire tank, whatever size the tank is on your version. We draw the contaminated fuel out, flush the lines and the fuel filter, and refill with fresh diesel before re-priming the system and firing up your engine.
It doesn't matter whether your ML is sitting on the forecourt or left on your driveway. You can take it away when the drain is done, and it'll be running on fresh diesel.
AdBlue removal from a diesel Mercedes ML, explained
AdBlue collects at the bottom of the tank instead of mixing in, so draining it completely is the opening step in AdBlue removal from a diesel Mercedes ML. An engine that has been run means flushing the fuel filter and lines through too, plus replacing the filter if it needs it.
What this covers is AdBlue that ended up in your diesel tank, not taking out or disabling the AdBlue system on the car.
What a fuel drain on the Mercedes ML will cost
The same model can make for quite different jobs, which is why we do not list a fixed price. How much was put in compared with the size of the tank, petrol or AdBlue, and the car's location all matter, but whether the ML has been driven or only started changes it most.
We can explain what is involved in the job if you ring with those details.
Queries on the tank and petrol in a diesel Mercedes ML
What does the Mercedes ML fuel tank capacity come to?
From 70 to 95 litres according to the version, and each version is listed in the table above.
Is petrol less of a problem in a larger tank?
That petrol is still there in a bigger tank, and still gets to your pump once the motor runs, even though a few litres make up less of the whole. All of it comes out with a fuel drain, as long as your ML is turned off.
Do you cover more than one diesel ML?
Our figures cover 11 diesel versions of the ML, all set out in the table above, so you can find yours there by the name printed on its badge.
Is it wrong fuel in my Mercedes ML if it is not diesel?
Only diesel belongs in the diesel tank. Petrol of any grade, super unleaded too, is wrong fuel, and so is AdBlue, which goes in a tank of its own.
Will you drain the Mercedes ML where it stands?
Yes. We travel to the vehicle, whether it's still on the forecourt or parked at home, and so it does not need to be moved or started.