Petrol and Diesel Compared

How to Tell If Your Car Is Diesel or Petrol

Nidhi Nangia
By Nidhi Nangia. Updated: July 3, 2019
How to Tell If Your Car Is Diesel or Petrol

Filling a vehicle’s tank with the wrong type of fuel can damage your car severely. In the past, diesel vehicles could be easily identified by the tractor-like sound they produced while running. But these days, advanced technology has worked towards silencing them and therefore it has become a lot more difficult to identify whether a car is diesel or a petrol. If you have hired a car from a car rental company, and need to know whether it is a diesel or petrol run car, you have come to the right place. In this oneHOWTO article will tell you how to tell if your car is diesel or petrol.


  1. How to know if my car is diesel or petrol
  2. What is the right fuel for my car?
  3. What happens if you put the wrong kind of fuel in your car?

How to know if my car is diesel or petrol

Distinguishing a petrol and a diesel car is pretty easy. There are a lot of signs that can indicate whether a car runs on petrol or diesel. These methods of detection include:

  • Finding a sticker: Car rental companies place stickers on their cars to indicate which fuel the vehicle uses. They may put these stickers on different places of the car, commonly on the key and/or dashboard. If you can’t find any sticker, open the flap on the car’s fuel cap as there might be a sticker on the inside. The sticker will indicate if the car is ‘Diesel only’, ‘Petrol only’. There may be other similar text that indicates the kind of fuel used by the car. You may also look for a sticker on the fuel filler neck or instrument bundle around the fuel gauge.
  • Knowing by the model of the vehicle: Go to the back side of the car and check the exact model of the car. Often, cars with diesel engines have the letter ‘D’ in their model name. For instance, Hyundai/ Kia – CRDi, Toyota - D.4D, Land Rover - Td6/TDV6, Honda - i-DTEC, Mercedes-Benz - CDI, BlueTEC etc. The letter ‘D’ in these model names indicates that they have a diesel engine. However, this is not rule of thumb, and the ‘D’ in their model name may be indicative of another other feature. Therefore, we suggest making sure of this by considering some other clues.
  • Checking the instrument cluster: Check the instrument cluster (digital dash) of the car for any written proof of which type of gas the car runs on.
  • Reading the car’s documents: Take out your vehicle’s documents, i.e; car owner’s manual. Go to the section on fluids. The type and grade of fuel required for the vehicle will be clearly indicated.
  • Calling your car’s helpline: You should be able to find a helpline number on the front or back of the car. You can call this number, speak to an agent and ask them which fuel the vehicle takes. Sometimes, the agent may ask the make, model, year and VIN number of the car in order to reply accurately. Therefore, before calling, sure that you have this information handy. If you have hired the car from a car rental company, or if you have borrowed it from a friend, call them and ask for required guideline.
  • Looking at the rev meter: Taking a look at the car’s rev meter can sometimes help you identify the kind of fuel it runs on. In most cases, the red area begins at around 6000 on petrol cars, and 4500-5000 on diesel cars. However, this will depend on the car type and model.
  • Noticing the glowplug indicator: A a diesel car has a glowplug (heating device) indicator that is supposed to light up when you ignite a cold engine. When you step into the car, just turn the key in the ‘on’ position but don’t ignite it. You will see a number of indicators glowing up. If you also see a glowplug indicator, then it means that it is a diesel car. [1]
  • Checking if the pump nozzle fits in: If you have checked everything already mentioned and are still not sure whether the car is diesel or petrol then we suggest going to a diesel specific filling station and trying to fill up the car. The nozzle of a diesel pump is thicker than a petrol one, and if it is a petrol vehicle, the nozzle of a diesel pump won’t fit in it. Generally, you will not be able to put diesel in a car that has a petrol engine. If you have a tough time putting a fuel pump into the neck of a diesel car, it probably means that it needs a petrol nozzle. However, a petrol nozzle is easily inserted into a thick diesel fuel opening. In addition, it can actually damage a number of your vehicle’s mechanical components, especially the fuel pump. [2]

What is the right fuel for my car?

Once you know that your car is a petrol car, you need decide which grade of petrol your car requires. If it is a diesel car, you can go to the diesel filling station and get it filled. But if it turns out to be a petrol car, then you have three choices to make. These petrol choice include; premium, mid-grade and regular petrol. Some vehicles require premium unleaded petrol for the best operation and efficiency. A vehicle that needs premium grade petrol can also run on regular grade petrol, but it may not be as efficient . If a vehicle needs regular gasoline, you may fill any grade fuel in it. Take note of these tips;

  • If your vehicle has a supercharged or turbocharged engine, then you are required to fill it up with premium grade fuel.
  • High horsepower and high compression engines, like those in exotic sports cars also require premium fuel for best performance.
  • Economy cars, family sedans, pickup trucks and SUVs usually require regular grade petrol only.

What happens if you put the wrong kind of fuel in your car?

In order to power the car, diesel works as a lubricating oil to keep the car’s components running smoothly. On the other hand, petrol is a solvent and does the opposite. When you fill a diesel engine with petrol, it causes friction in between the auto parts, and causes damage to the pump and fuel lines. If you try to drive a diesel car with petrol in it, it will eventually stop after a few miles, causing extensive damage to the engine. On the other hand, filling diesel into a petrol vehicle is nearly impossible, as the pump nozzle won’t just fit in.

If you want to read similar articles to How to Tell If Your Car Is Diesel or Petrol, we recommend you visit our Cars category.

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How to Tell If Your Car Is Diesel or Petrol