Petrol in a Diesel Mazda CX-5? Leave It Switched Off
We'd urge you to keep the motor off if you've put petrol in a diesel Mazda CX-5 and not run it yet, and that goes for moving it off the forecourt as well. The petrol cannot get out of the tank as long as the motor is off, so your CX-5 can usually be set right with a fuel drain.
Petrol in Diesel empties wrongly fuelled vehicles where they are, so the Mazda CX-5 can be left on the forecourt or wherever it ended up. Phone us first then let us walk you through it, rather than attempting anything on your own.
Your first steps with petrol in a diesel CX-5
- Motorists frequently drive away without noticing anything is amiss, because a diesel CX-5 will normally start and run on petrol and can seem normal for the first few miles. So keep the motor off.
- The ignition has to remain off as well, as switching it on sets the fuel pump priming on a lot of diesels, and your pump then draws fuel from your tank.
- Filling up with diesel to dilute it is a mistake, even with super unleaded, which is petrol too. The tank in your CX-5 holds up to 58 litres, and each litre of diesel put in is more contaminated fuel for us to drain.
- When your vehicle is blocking a pump, pop it in neutral then roll the vehicle clear. Forecourt attendants are normally glad to lend a hand.
- If the badging gives the exact version, for example the CX-5 2.2 D AWD, give it when you ring 0333 366 0103. Tell us as well which CX-5 you have and where it is parked, about how much petrol was put in and whether the motor has run.
Wrong fuel in your Mazda CX-5 after your motor has been run
Starting your motor is what draws the wrong fuel in your Mazda CX-5 out of the tank, and only then does it begin to affect your engine. The high-pressure fuel pump and the fuel injectors in a diesel engine are lubricated by your fuel flowing through them. That lubrication is taken away as soon as petrol dilutes the diesel, so the harm, where there's any, comes from driving on the mix.
Pull over in a safe place and switch off when the CX-5 has already been driven. All the same, we can take all the contaminated fuel out, by draining the tank and then rinsing the fuel lines and the filter. Very few cars that are caught soon and cleaned out properly end up with lasting harm.
Your Mazda CX-5 fuel tank capacity, by version
If you filled up while the tank was almost empty, the same few litres make up more of your fuel in it, and the risk rests on that proportion, so the capacity of the tank counts.
It does not matter which version you own, because each diesel Mazda CX-5 in our figures uses the same tank, taking 58 litres.
Finding your diesel CX-5 variant
Check the badge on your boot lid, which normally shows the variant, then tell us what it says when you call.
There is one engine size throughout our list, 2.2 litres.
There are AWD versions on the list too.
Put AdBlue in a diesel Mazda CX-5?
Some diesel cars hold a mix of water and urea, known as AdBlue, in a tank of its own with a dedicated filler, and rely on it to clean up their exhaust. The key should stay out of your ignition if you've got AdBlue in a diesel Mazda CX-5 through the incorrect filler, and that includes shifting your vehicle.
The fuel pump gets no lubrication at all from AdBlue, which is mostly water and won't burn. It will not blend with diesel either, and drops to the base of the tank, the very location your pump pulls from, so a tank holding up to 58 litres won't dilute it.
No matter how modest the quantity, some of that is sucked into the line. Crystals of urea form in the fuel filter, the injectors and the remainder of your fuel system once the water dries off, and they corrode the metalwork they touch.
Look under the fuel flap where your CX-5 has an AdBlue filler, as on a lot of motors it is right alongside the diesel filler. The nozzle for AdBlue is far smaller than the diesel one, and the cap is typically blue.
The fuel drain on your Mazda CX-5, in order
Every fuel drain on your Mazda CX-5 is done at the vehicle, so it never needs to go to a garage. Before we fire up your motor, your system is primed and the tank filled up with fresh diesel. First comes finding out what was put in and whether it's run, emptying a tank that holds up to 58 litres on the CX-5, and flushing the lines and fuel filter.
Once we've finished, the CX-5 is running on fresh diesel and you can drive the car away.
AdBlue removal from a diesel Mazda CX-5
Like emptying petrol, AdBlue removal from a diesel Mazda CX-5 runs through the same stages. We flush deposits out of the pipes too if the CX-5 has been run, and replace your fuel filter where needed, because AdBlue gathers in the bottom of your tank rather than blending in and may leave them behind.
AdBlue removal here means getting AdBlue out of the diesel tank once it has been put in the wrong filler. It does not mean taking out or switching off the AdBlue system on your car.
What decides the cost of a fuel drain on the Mazda CX-5
The work changes from one task to the next, so we do not publish a fixed quote. The main factors that shape it are these:
- starting or driving the CX-5, which makes more difference than anything else
- a tank's size next to the volume that was put in
- whether it was petrol or AdBlue
- where the CX-5 is, and whether we can bring our van to it safely
Call with those answers and we'll be able to say what's likely to be involved.
Questions about petrol in a diesel Mazda CX-5
How many litres is the Mazda CX-5 fuel tank capacity?
58 litres. The tank is the same size whichever version you drive.
Is it OK to add diesel after just a little petrol in my CX-5?
We would advise against it. The petrol remains in the fuel system when you drive, as adding diesel only reduces its share and removes none of that. Your CX-5 generally requires nothing more than a drain if just a modest amount went in, and that gets the petrol out completely.
Is a trip to the Mazda dealer necessary for my CX-5?
There's no reason to take it elsewhere. We empty and clean your CX-5 where it is parked, and we are independent, with no link to Mazda or its dealers.
Does my policy cover wrong fuel in my Mazda CX-5?
It is worth checking your policy, as misfuelling cover is included in some and not others. Whichever way it reads, we come out and empty the car.
The diesel went into the AdBlue filler on my CX-5. What now?
In that case, too, leave your key out of your ignition. The AdBlue system will need emptying, and when your vehicle is driven that way, it will most likely display an alert and go into limp mode. Please say which tank took the diesel when you ring.
I drove my CX-5 before I realised. What should I do?
Till we get to you, your engine needs to remain off, so stop where it's safe then switch it off. Long-term damage is very uncommon if it's caught early like this, and we empty the system and clean it where you have pulled over.