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What Happens When You Put the Wrong Fuel in Your Car?

Statistics indicate that a motorist somewhere in the United Kingdom puts the wrong fuel in their car every three and a half minutes. In fact, one of the most common questions we get is – I’ve put the wrong fuel in my car, what should I do? Here’s an is an in-depth outline of the steps you should take if you happen to misfuel.

First, don’t start your car. You might be lucky to get some assistance from attendants if you’re at a petrol station. At the very least, they can help you push your vehicle away from the pumps into a parking lot.

Can You Drive Your Car?

Of course, the fact that you shouldn’t start your vehicle means you can’t drive it. See, when you run the engine, you’ll create a situation that allows the wrong fuel to penetrate deep into your car’s delivery system and related ancillaries.

Sure, you may get away with a couple of miles with a diesel-powered vehicle. However, the case is different with a petrol car – it is unlikely to run for more than a minute.

You Have Driven Your Vehicle With the Wrong Fuel, Have you Made it Worse?

Unfortunately, yes.  But then again, it depends on several factors. A modern diesel car, for instance, has robust ancillaries and an engine system that will respond swiftly to wrong fuelling, reducing the damage. Even then, it is essential to note that petrol may cause corroding if it comes into contact with some ancillaries in the drivetrain of a diesel-powered vehicle. It is crucial, therefore, that you act quickly to minimize the risk. The ancillaries likely to get damages in such a scenario include catalytic converters and the fuel pump.

Petrol cars will not start – if they do, they’re less likely to run for more than a few seconds. The thing is, diesel is relatively thicker than petrol. It is less combustible as well. Regarding damage, the same rule applies, even though you will have to deal with more complications if your vehicle is old and has higher mileage. More specifically, misfuelling is likely to affect the following elements of the drivetrain;

  • Catalytic converters
  • Fuel pump
  • Injectors
  • Valve seat and guides
  • Contamination of the fuel tank

What Should You Do If You Mis-fuel Your Car?

Petrol in Diesel

As stated, don’t start your vehicle. However, if you own an automatic car that doesn’t have a traditional key, you will have to start it to disengage the steering lock. The idea is to allow you to take it to a parking bay easily. The only thing you need to do here is to ensure that the engine doesn’t run for more than a few seconds.

Call an emergency fuel service to dispatch a technician who will then drain your vehicle immediately, and no further action is necessary. The same rule applies if you have driven your car. However, you should change the fuel filter a couple of days after removing the contaminated fuel and restarting your vehicle.

Diesel in Petrol

As a rule of thumb, you shouldn’t start your car. Get in touch with a reliable fuel drainage company to remove the contaminated oil from the tank. You can restart your vehicle from this point onwards. However, if you’d already started the engine, you should flush the fuel tank thoroughly after draining.  Note – it might take you up to two times longer to clean the tank than it would if you misfuel a petrol car. Also, you’ll experience a substantial amount of smoke as the diesel residue burns off.

What Type of Repairs Should you Expect?

You may have to replace the fuel tank altogether depending on the severity of contamination. On top of that, you will need new connecting pipes, fuel pump, injectors, and fuel lines. An excellent emergency fuel service will drain and flush and supply a new filer depending on availability. Some will even offer an additive to help clean, lubricate and get rid of any contaminated fuel that might be in your car’s system. Advanced additives can increase cetane levels and by extension boost combustion.

How Much Will it Cost You?

Well, there is no definite answer to this question. However, you can estimate the cost based on the following there options;

  • Recover to a main dealer if your vehicle is under warranty – Anywhere between £2,000 to £10,000
  • Recovery to local dealer plus fuel drain – Anywhere between £300 and £400
  • Mobile roadside fuel drain – Anywhere between £175 and £300

Option one offers a greater scope to deal with associated problems especially if you can won’t restart. On the flipside, however, the contaminated fuel will stay longer in your vehicle, potentially costing you more in repair and recover not to mention the extended car downtime.

Option two provides the peace of mind that all related ancillaries, the fuel storage, and delivery system will get replaced. Still, you’ll have to deal with longer vehicle downtime and higher cost.

Option three has the advantage of draining the contaminated fuel immediately, enabling you to continue with your journey. The only downside is that it may not address the damage caused to ancillaries if your automobile fails to restart. It offers a quick fix though, and one of the best choices if misfuel your car.

The Bottom Line

There’s a likelihood that you’re going to put petrol in your diesel tank and vice versa. At times, you’re in a rush, hungry or distracted. So, make sure that you remain focused every time you drive into a fuelling station. You can consider sticking a note on your car’s fuel cap to reduce the chances of misfuelling.

Or, you can buy a cap that covers the filler neck to prevent a petrol nozzle from fitting into it if you have a diesel car. Sadly, however, there isn’t an equivalent of such caps for petrol vehicles. Remember, be sure to call an emergency fuel service in the unfortunate event that you misfuel.