When you go to fill your car up at the fuel pumps, you obviously know that there are two types of fuel available. You have the option of filling up with Diesel or Petrol, depending on what your vehicle runs on. But, what happens if you fill up with the wrong type of fuel and end up putting diesel in a petrol car?Well, lets examine both types of fuel first. Petrol is a highly refined derivative of crude oil which contains a mixture of hydrocarbon chemicals. Most of the chemicals in petrol contain around 5-15 carbon atoms. Diesel fuel however is less refined and a more light weight crude oil product, and is in fact a fuel oil, containing 20 or more carbon atoms. Apart from the difference in chemistry, petrol and diesel behave differently in engines. Diesel is designed to self ignite, which is why you won’t find a spark plug in a car that runs on diesel as the diesel only requires the engine pressure and temperature to burn. Petrol on the other hand is blended to avoid self-ignition, thus relying on the spark plugs in the engine to ignite it. Now because these two fuels are so different, petrol engines are not supposed to be run on diesel fuel, so attempting to do so can cause quite a few problems. In most cases a petrol car filled with diesel fuel will not run at all and the diesel will likely clog the fuel filters, fuel lines and fuel injectors. If you do manage to get a petrol vehicle to run on diesel fuel, the performance will be sluggish and very poor. Also, the cylinders in a petrol engine do no produce the same sort of temperatures as its diesel counterpart, so the diesel fuel will not ignite correctly and can damage the cylinder linings and engine timing cycle. If you’ve put more than 5 litres of diesel in a petrol car engine by mistake, do not drive it. If you have driven it, pull over immediately. The longer the wrong type of fuel is in your engine, the more damage it will cause. You can have the car towed home and have the diesel fuel siphoned out and refilled with unleaded petrol. You’ll then be able to carry on driving the vehicle with no problems at all. You may get some smoke coming from the exhaust as the engine burns off the last drops of diesel that remain in the system, and also suffer lower fuel mileage. This shouldn’t last very long though. A much quicker and safer alternative is to contact a wrong fuel specialist as soon as you’ve realised that you’ve put the wrong type of fuel in. This involves a mechanic coming out to you and draining the diesel from your petrol car at the roadside. They will then refill your vehicle up with petrol and make sure that the car is running smoothly so you can carry on with your journey. With over 150,000 cases of people filling up their vehicles with the wrong type of fuel every single year, you are not alone. The main thing to worry about is how quick you can get the diesel fuel out of your petrol car, as it is possible that leaving it sit in your engine for too long can cause more damage. A mobile wrong fuel specialist is the best way to deal with the problem, both in terms of speed and cost.