Filled-up with the wrong fuel? Here's what SA motorists should do

<B>PETROL VS. DIESEL:</B> Filling up with the wrong fuel can lead to serious engine damage. <I>Image: iStock</I>
<B>PETROL VS. DIESEL:</B> Filling up with the wrong fuel can lead to serious engine damage. <I>Image: iStock</I>

Cape Town - You arrive at a fuel station, instruct the attendant which type of fuel (and how much), fill-up, and leave - it's a scenario you will repeat throughout your time behind the wheel and one that's played out a million times a day in SA.

Often when refilling a vehicle's fuel tank, motorists trust that the attendant will add the right fuel to the vehicle.

A lack of communication or not checking up on your vehicle's fuel requirements can cause serious damage to the engine.

Here's what you should do

Whether you've added diesel instead of petrol, or vice versa, to your car, there's still time to avoid a huge repair bill.

To find out more, BP South Africa shares advice on what to do if you've accidentally filled-up with the incorrect fuel for your vehicle:

1 Adding petrol to a diesel tank or vice-versa - Which will cause more damage?

BP: It is a bigger risk to have petrol contamination in a diesel vehicle because petrol has a higher calorific value and diesel has a higher compression ratio.
2 Which vehicle components are harmed by driving with the incorrect type of fuel for your vehicle?

Depending on the contamination ratio, you can receive different levels of damage:

Typically if you have a diesel contamination in a petrol vehicle:
  • No permanent damage to major components.
  • You will need to drain and flush the whole fuel system.
  • Replace fuel filter.
  • In extreme cases, drain engine oil and replace oil and oil filter.
  • In extreme cases, the lambda censor might have to be replaced.

READ: BP launches its best ever range of dirt-busting fuels

Typically if you have petrol contamination in a diesel vehicle:
  • In minor cases it will be similar to petrol-diesel scenario.
  • Typically we look at the fuel pump and fuel injectors, plus the above list.
  • In extreme cases it would damage the pistons and result in the diesel engine needing to be rebuilt.
3 What are the warning signs drivers should be aware of?

BP: In extreme contamination levels the vehicle will not start. If you have diesel in a petrol vehicle, in a moderate level of contamination, the diesel vehicle will begin to smoke. Typically a dark smoke and the vehicle will be sluggish and will not be able to to rev up to a higher rpm.

In the case of a adding petrol in a diesel vehicle, the symptoms are dependent on the contamination ratio of petrol and diesel. Typically, the diesel “clatter” sound will be noisy than normal. 

 Image: iStock

4 What should motorists do?

The best thing is to switch the vehicle off and have it towed to a workshop. The longer the vehicle is driven, the higher the level of damage. You should avoid driving the vehicle.

5 Are there any specific or additional risks to having the vehicle privately towed to the nearest service station?

In the event that your car is towed to the nearest service station, the best thing would be to alert the service station management that it is parked there and that arrangements to having it towed are being made. This is to just ensure the security of the vehicle.

READ: How SA drivers can save fuel with good road manners

6 How long is the repair process?

The repair time will depend on:

  • The type/make of the vehicle.
  • After sales support from the OEM 9 (Spare availability).
  • Expertise of the workshop (typically from a day to a week).
8 What should motorists do to avoid using the incorrect fuel for their vehicle?

BP: You should get out of your vehicle when refueling and ensure that the correct fuel is being dispensed into your vehicle.

If you notice a mistake at the time of refueling, do not start the vehicle, push it the side of the forecourt and drain the fuel tank. This way if the vehicle has not being started, the fuel would not have being pumped from the tank into the vehicles fuel system.

This will result in a much faster and cheaper repair.

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