Petrol in a Diesel Audi A8, and You've Driven It
If you have travelled on petrol in a diesel Audi A8, stop as soon as it is safe, switch the engine off then leave it off. Where you've pulled up, we can still put it right, and damage that lasts is very uncommon once it's spotted soon.
Your Audi A8 can stay where it has stopped, as Petrol in Diesel comes out to it, drains its fuel tank there and cleans its fuel system of petrol. We go once it's running again on fresh diesel.
When petrol in a diesel A8 shows itself
It is often a few miles before the signs appear, because with petrol in the fuel tank a diesel A8 will often run as usual at first. With petrol or AdBlue inside your fuel tank, these are the ones motorists tend to spot:
- the motor is short of power, particularly whenever it has to pull
- it runs rough, or the idle becomes uneven
- more smoke than normal comes from the tailpipe
- the dash displays warning lamps
- the motor cuts out and may not restart
Check your receipt if any of these began after you filled up, because it will show which fuel was put in.
Wrong fuel in your Audi A8 and the result of travelling on it
Wrong fuel in your Audi A8 sits in the fuel tank until the engine pulls it out, and driving is what pulls it through your filter, your high-pressure pump then your injectors. Diesel protects your fuel pump and the injectors as it passes through them while petrol thins it, and so the farther the A8 is taken, the more of the fuel system the mixture reaches.
That is the reason to stop the moment you can and not finish the journey. Travelling a long way on tainted fuel is what can cause harm, and if a motor is stopped soon, a drain and a clean are normally all it requires.
Another version of the A8 is no different from the A8 3.0 TDI here, and so which one is yours makes no difference.
Where you have pulled up
Taking the A8 anywhere isn't needed. We come to it at the side of the road or outside your house, so there's no need to restart the vehicle or organise a recovery truck.
A safe place, clear of the traffic, is the place to wait if you are beside a main road, with your hazard lights on.
Phone 0333 366 0103 and tell us where you are, what A8 it is and roughly how far it has been driven. If the badge shows the version, such as the A8 4.0 TDI quattro, that helps as well.
After it's been driven: fuel drain on your Audi A8
There is a step more to a fuel drain on your Audi A8 after it was driven than to one on the forecourt. We empty your fuel tank first, then open up the fuel lines and then flush them through with your filter, so no petrol is remaining between your fuel tank and the engine. The system is primed once fresh diesel is in, and the motor is started to make sure it runs properly.
After it's run: AdBlue in a diesel Audi A8
Watch for smoke, rough running and warning lamps when AdBlue in a diesel Audi A8 has been driven on, as your car might also stall. Settling to the bottom of the fuel tank, where your fuel pump picks up fuel, AdBlue reaches your fuel line quickly, and it doesn't burn or lubricate. The urea forms crystals in your fuel filter and the fuel lines as its water dries.
AdBlue removal from a diesel Audi A8: what it involves
AdBlue removal from a diesel Audi A8 that has been run means draining the tank then clearing the crystals from the lines and your fuel filter, and we'll change the fuel filter if it needs it.
Nothing here involves turning off or removing the AdBlue system. It deals with fluid in the diesel tank, and a dedicated AdBlue tank your A8 has is left alone.
Engine sizes and Audi A8 fuel tank capacity
Each version of the Audi A8 in our data comes with a diesel fuel tank of 90 litres.
You will find TDI badging on diesel A8 versions.
The A8 L 4.2 TDI quattro has the biggest engine at 4.2 litres, and the A8 2.5 TDI quattro has the smallest, at 2.5 litres.
The list includes Quattro versions.
| Version | Fuel tank |
|---|---|
| Audi A8 2.5 TDI | 90 litres |
| Audi A8 2.5 TDI quattro | 90 litres |
| Audi A8 3.0 TDI | 90 litres |
| Audi A8 3.0 TDI quattro | 90 litres |
| Audi A8 3.3 TDI quattro | 90 litres |
| Audi A8 4.0 TDI quattro | 90 litres |
| Audi A8 4.2 TDI quattro | 90 litres |
| Audi A8 L 3.0 TDI quattro | 90 litres |
| Audi A8 L 4.0 TDI quattro | 90 litres |
| Audi A8 L 4.2 TDI quattro | 90 litres |
Costing a fuel drain on the Audi A8 after a drive
Whether it was petrol or AdBlue affects what a fuel drain on the Audi A8 costs after driving on it, though it hinges mainly on how far it went and where it has ended up. We can explain what the job will need once you phone with those details.
Questions after driving with petrol in a diesel Audi A8
Will my A8 be ruined?
Very probably not. With the vehicle stopped soon and your fuel system emptied and cleaned wherever you've pulled up, which is what we do, permanent damage is uncommon.
Can I drive it home first?
It is better not to. Every mile on tainted fuel carries it further through your fuel system, and we're able to drain the A8 where it stands, which means there's no reason to shift the vehicle.
Stalled, and it will not restart: what should I do next?
Leaving it alone is wiser than having another go, since each try pulls that blend further through. With it emptied and flushed and clean diesel in, we prime the system and get it started for you.
Does it matter which A8 I own?
There are 10 diesel versions of the A8, and the badge on the tailgate says which one you have. Knowing that helps us when you call.
Will my insurance cover wrong fuel in my Audi A8?
When your car is sorted, it is worth looking at your policy, because some offer misfuelling cover. We come out whether it does or not.