Skip to content

The Dangers of Adding Petrol to a Diesel Car: Why Professional Assistance Is Essential

Every year, thousands of motorists accidentally fill up their diesel vehicles with petrol instead of diesel fuel. While it might seem like a harmless mistake, putting petrol in a diesel engine can result in serious problems that require immediate attention from a professional mechanic. In this article, we explain why you should always seek help from call professionals when faced with this common error and how they can mitigate any potential damage.

What Happens When You Put Petrol in a Diesel Engine?

Diesel engines operate differently than petrol engines; they require higher compression ratios and much thicker fuels due to their design. Using petrol in a diesel engine can lead to severe consequences, including:

  1. Ignition Issues – Unlike gasoline engines which ignite via spark plugs, diesel engines combust fuel through high pressure and heat generated from the injector pump. The lower octane rating of petrol causes it to burn too quickly and unevenly leading to misfires, backfiring, and rough idling issues.
  2. Clogged Filters & Injectors – Due to the difference in viscosity between petrol and diesel fuel, petrol has a tendency to clog filters and injectors. The added moisture content in petrol results in corrosion of sensitive components within the system causing permanent damage if left untreated.
  3. Damaged Fuel System – The lubricant properties present in diesel fuel aid in protecting internal engine parts from wear and tear whereas petrol lacks similar characteristics that could potentially strip away vital sealing rings and gaskets resulting in further complications down the line.

Why Seek Help From Call Professionals?

While some people believe flushing the tank with diesel fuel immediately after realizing their error is sufficient, doing so can still inflict irreparable damage. Here are three reasons why it’s essential to contact call professionals when dealing with petrol in diesel errors:

  1. Correct Diagnosis – After mistakenly filling up your vehicle with the wrong type of fuel, the first step is determining the extent of contamination. Some diesel tanks might only contain trace amounts of petrol, requiring simple draining procedures whereas others may contain enough to cause catastrophic damages necessitating expensive repairs. Only trained professionals can accurately diagnose the severity of the issue and recommend suitable solutions based on the specific circumstances surrounding each case.
  2. Specialized Equipment – Professionally certified technicians utilize specialized equipment designed specifically for removing excess petrol from diesel fuel systems. Their tools include powerful suction pumps capable of extracting impurities from deep within the tank, injectors, and filter systems. Utilizing improvised DIY fixes could worsen existing issues and create new ones.
  3. Expert Advice – Experienced mechanics understand the nuances of each fuel type’s chemical composition and how they interact with one another. They are better placed to advise owners on best practices regarding future refuelling habits and maintenance routines to prevent recurrence of petrol in diesel mishaps.

Preventive Measures Against Accidentally Fuelling Your Vehicle With The Wrong Type Of Fuel

To avoid unwanted incidents, it is advisable to implement certain precautions beforehand. Below are practical tips that can significantly decrease the likelihood of erroneously adding petrol into your diesel fuel tank:

  1. Pay Attention To Labels And Colours – Most modern automobiles feature distinct labels and colours signifying either diesel or petrol fuel caps. Make sure you double check the label colour to confirm that the right cap is being attached correctly.
  2. Use A Funnel – Even when being cautious, it’s easy to lose concentration whilst filling up your tank especially in busy stations or unfamiliar locations. Inserting a funnel into your vehicle’s fuel neck helps guide fuel precisely where it’s supposed to go preventing accidental spills onto the incorrect side.
  3. Keep A Record – It’s recommended to maintain a logbook documenting all fuel purchases made over time. Regular inspections comparing notes can highlight discrepancies that indicate previous petrol in diesel mishaps, allowing quick rectification actions.


Filling up your diesel car with petrol is a widespread problem affecting countless unsuspecting motorists worldwide. Although the initial reaction might be to ignore the incident and hope for the best outcome, this strategy often leads to aggravated predicaments that compound in additional repair costs. Instead, it’s crucial to contact call professionals who hold expertise in handling such situations professionally and efficiently. Follow our recommendations above to safeguard against these types of scenarios from occurring as well.