Why you should avoid an empty fuel tank

Date: Sat 4th March 2023   |   Author: Modeten

The potential consequences of driving with your tank on empty

We’ve all been there and for many the fuel light can be the bane of owning a car. But whether it's just before pay-day and money is tight or you simply forgot to fill up on your way past the petrol station, there are a number of reasons why you won’t want to run your car on empty.

According to the latest figures from the AA, around 300 cars a week have to be recovered with the tank on empty! In this blog we look at why you should always keep your car well topped up and what might happen if you don’t.

How to know when your tank is nearly empty

The easiest way to tell that you’re running your car with the tank on empty or nearly empty is from your car’s fuel light. But every car fuel light will illuminate at a different time so don’t use this as a steadfast guide. It’s not easy to define how many miles you have left in the tank from just looking at the fuel gauge, but you should think twice about driving if you have less than a quarter of a tank in the car.

Many newer cars now have smart fuel gauges that also let you know the range you have left before your engine dies. But even this may change depending on your speed and the kind of driving that you’re doing.

Why shouldn’t you run your car with a nearly empty fuel tank?

Running your car with a virtually empty fuel tank will sound ludicrous to many drivers, but unfortunately the amount of roadside recoveries occurring as a result of running dry shows that this is a real problem in the UK. Here are just a few reasons why you shouldn’t risk driving with low fuel:

Unreliable fuel light and gauge

If you’re relying on your fuel gauge being accurate, leaving fuel to run low may be playing a risky game. Obviously, the newer the car the more accurate your fuel gauge should be, but drivers with older cars should never leave refilling to chance. A number of factors can affect what the fuel gauge reads, including whether you’re just starting the car in the morning or if you’re on a particularly long drive. If you notice that your fuel gauge is acting inconsistent then it may need a mechanic to repair the issue.

Low fuel can damage the fuel pump

Consistently driving your car on low fuel can cause a number of internal issues for your vehicle over time. Petrol in an empty fuel tank can collect debris that has built up over time and when this is pumped through your vehicle it can clog up various components such as your fuel pump and filter. A low tank can also lead to the vehicle pumping air, which may also cause issues for your fuel pump and other components that require fuel to function.

A completely empty fuel tank can be dangerous

The consequences of running out of fuel are a sudden loss of power to your engine, potentially on a busy road. This in itself is dangerous. Now consider having to pull over without the use of your engine, if you’re on a hill or in the middle lane with no hard shoulder it’s impossible. Being stranded in your car is always a potentially dangerous situation to be in and not one worth risking.

When should you top up fuel?

If you follow these tips you should never have to be recovered from the side of the road as a result of an empty fuel tank – unless there’s an issue with your gauge of course. You know it’s time to top up fuel if:

• Your fuel light is illuminated
• If your fuel light is on, you should top up at the next petrol station that you reach. If you’re concerned about the price of a particular fuel station then just think about the price, embarrassment and inconvenience of running out of fuel by the side of the road!
• You have less than a quarter of a tank
• If you have less than a quarter of tank then you should top-up while you remember. Your fuel light will come on soon and there’s no point waiting any longer!
• You’re about to set off on a long drive
• This should go without saying, but if you’re about to set-off on a long drive then you shouldn’t do so without a full tank of petrol.
• You’re using the motorway and you have less than half a tank of petrol

Driving on motorways uses more fuel due to the amount of revs your engine will be doing by driving in excess of 60mph for long periods of time. Overtaking and acceleration are also bad for fuel consumption and if you get stuck for long periods in traffic your next top-up could be in the hard shoulder.

How can I tell my fuel tank is empty?

If your car’s fuel light has been illuminated for some time and your car cuts out of power completely then it’s probably caused by a completely empty fuel tank. However, leading up to a complete loss of power you may notice that the car is stalling easier than usual or not starting as quick as it should. If you park your car with low fuel, you should also be aware that it might not start the following day, in particular if it’s parked on a slope.

What to do if I have a completely empty fuel tank

If you have a completely empty fuel tank and your car cuts out whilst you’re driving, you should put your hazard lights on and leave the vehicle only if it is safe to do so. If it is not safe to do, such as in the outer lanes of the motorway, you may need to contact the police. If you subscribe to a roadside recovery service then you should contact them immediately to remove your car to minimise the disruption to traffic.

Depending on the terrain and how busy the road is it may be possible to push your car to the side of the road. You should only do this if there are at least two people to help and you should always remain behind the wheel to control the car. Never push a car on your own or in busy traffic.

If you’re by the side of the road and you’ve run out of fuel then you should walk to the nearest petrol station if there is a pavement to walk on and it is safe to do so. Here you’ll be able to purchase a petrol can to fill with fuel so that you can restart it again. If your car is completely empty, you may require two cans to start it again and this will only get you as far as the petrol station to refill properly. Ensure you lock the car and only leave it if it is parked in a legitimate position.