What the Tank Holds: Petrol in a Diesel Audi A5
The capacity of the fuel tank is one of the first things to know once you have put petrol in a diesel Audi A5, as the proportion of the fuel that is now petrol rests on it. Our guide sets out the tank on every version of the Audi A5 we hold data for, along with the motors it was sold with.
Regardless of how big the number is, there's one piece of advice after the event. With the engine kept off, ring Petrol in Diesel and the car will be drained where it is.
The Audi A5 fuel tank capacity for each version
Versions of the Audi A5 vary, and so the diesel tank holds anything from 61 to 65 litres depending on yours.
In our figures, the A5 Sportback 2.0 TDI quattro carries the smallest tank and the A5 Cabriolet 2.7 TDI the biggest.
As a comparison, 63 litres is the figure for the A5 Sportback 3.0 TDI.
The tank takes 63 litres in the A5 Coupe 3.0 TDI.
| Version | Fuel tank |
|---|---|
| Audi A5 Cabriolet 2.0 TDI | 65 litres |
| Audi A5 Cabriolet 2.0 TDI quattro | 64 litres |
| Audi A5 Cabriolet 2.7 TDI | 65 litres |
| Audi A5 Cabriolet 3.0 TDI | 64 litres |
| Audi A5 Cabriolet 3.0 TDI quattro | 64 litres |
| Audi A5 Coupe 2.0 TDI | 65 litres |
| Audi A5 Coupe 2.0 TDI quattro | 64 litres |
| Audi A5 Coupe 2.7 TDI | 65 litres |
| Audi A5 Coupe 3.0 TDI | 63 litres |
| Audi A5 Coupe 3.0 TDI quattro | 64 litres |
| Audi A5 Sportback 2.0 TDI | 65 litres |
| Audi A5 Sportback 2.0 TDI quattro | 61 litres |
| Audi A5 Sportback 2.7 TDI | 65 litres |
| Audi A5 Sportback 3.0 TDI | 63 litres |
| Audi A5 Sportback 3.0 TDI quattro | 64 litres |
Wrong fuel in your Audi A5: what a few litres means
How full your tank was when you filled up determines the share of petrol, as wrong fuel in your Audi A5 blends with whatever diesel was already there. Up to 65 litres go into your tank. Filling an almost full one with a couple of litres of petrol leaves only a minor share of petrol in the total, whereas the same quantity in a nearly empty tank is far more of what your engine would draw.
Often, people ask at what point that petrol gets to be too much. It is more helpful to find out if the motor has been run, as a running engine is what moves that mixture out of the tank and through the pump and the injectors.
A fuel drain is the safe option no matter what the proportion, and with a modest quantity it's generally all your A5 needs.
Which engines your diesel A5 came with
The engine in your A5 shows in the version name on the badge. Note it before you phone.
The badges on the diesel versions of the A5 within our data are TDI.
At the lower end of the range sits the A5 Coupe 2.0 TDI quattro at 2.0 litres, and at the top is the A5 Cabriolet 3.0 TDI quattro at 3.0 litres.
Within the A5 versions in the figures are Cabriolet, Sportback, Coupe and Quattro ones.
Call anyway if you're not certain which version you own, and we'll figure it out with you.
Tank size and AdBlue in a diesel Audi A5
Tank size plays out differently with AdBlue. With AdBlue in a diesel Audi A5, the diesel already inside your tank doesn't weaken it. Being mostly water, AdBlue stays separate from your diesel and settles to the base, which is where your pump draws from. Even a tiny amount gets into your fuel line.
As the water in AdBlue evaporates, the urea left behind forms crystals in your lines and the fuel filter and eats into the metal next to it, and AdBlue doesn't combust or give your pump any lubrication either.
A separate tank with a dedicated filler carries the AdBlue on some diesel cars, frequently beside the filler for diesel under the same flap. If your A5 has an AdBlue filler, the diesel nozzle is the larger of the two, and the AdBlue cap is usually blue.
Fuel drain on your Audi A5
A fuel drain on your Audi A5 empties the entire tank, whatever its size in your version, and it is done where the vehicle is sitting. Clean diesel goes in after the tainted fuel is pumped out and the fuel lines and the fuel filter are purged, and then the fuel system is primed and your engine started.
Parked at home or still at the pump, your A5 gets the same drain. Once we finish this drain, the car is running on clean diesel and free to drive away.
AdBlue removal from a diesel Audi A5
Clearing the tank fully is how AdBlue removal from a diesel Audi A5 starts, because AdBlue doesn't blend in and collects at the bottom instead. If the engine has run, we flush the lines and the filter through as well and change the fuel filter if it needs it.
This is about AdBlue that has got into your diesel tank. It's not removing or turning off the AdBlue system on your car.
The price of a fuel drain on the Audi A5
We do not publish a fixed price, since two jobs on the same model can be quite different. The biggest factor is whether anybody has started or driven the A5. Then comes the amount that went in against how big the tank is, which liquid it was, and where the vehicle is now.
With those details, we can explain what the job will need when you phone.
Tank questions about petrol in a diesel Audi A5
What is the fuel tank capacity of the Audi A5?
Between 61 and 65 litres, depending on the version. You can see each one in the table above.
Does petrol matter less with a bigger tank?
In a larger tank, petrol makes up a smaller part of the total, yet it hasn't gone anywhere, and it reaches the pump once the engine runs. Keep your A5 turned off and emptying it gets every bit of the petrol out.
How many versions of the diesel A5 are in your data?
There are 15 diesel A5 versions in our figures, and the name on your badge tells you which row of the table above is yours.
What counts as wrong fuel in my Audi A5?
Everything apart from diesel in your diesel tank, which means petrol of any grade, super unleaded as well, or AdBlue intended for its own dedicated tank.
Will you drain the Audi A5 where it stands?
Yes, wherever it is. Parked at home or still at the pumps, your car stays put and is not started, because we travel to it.