How far can I drive with my fuel light on?

This is a commonly pondered motoring query and having a basic knowledge of fuel consumption can give you a better sense of security throughout your driving life. So, how far can you drive once your fuel light comes on? Let’s take a look at a rough guideline.

Generally speaking, people like to go as far as they can on a tank of fuel. Whether it be to stretch your fuel fill-up until payday, or you might’ve forgotten to fill up the night before, and if you stop now, you’ll be late. Or you might just be an adrenalin nut who likes to live on the edge.

When you haven’t got very much fuel left in your tank, the ‘low fuel’ light will illuminate. It’s either a light shaped like a petrol pump or a message on your instrument cluster display. In some cases, it’s simply an amber light that lights up, along with a chime. 

In many vehicles, the problem is that it doesn’t tell you exactly how far you can still travel before you run out of fuel.

The point at which the fuel light comes on could be triggered either by an onboard distance-to-empty calculator, or by the fuel level sensor. You might have 6% of a tank left, or it could be anywhere from four to eight litres of fuel*.

But that still doesn’t tell you how far you can travel.

Remember, it isn't always Accurate

Your fuel gauge tells you only how much fuel you have remaining. And unfortunately, you can’t always trust it to be accurate.

Between mechanical problems and inconsistencies in manufacturing, your fuel light could come on earlier than other similar vehicles, or it could come on right before running out of petrol or diesel.

How Far Can I Go when My Fuel Light is On?

Once your fuel light has illuminated, you’re risking the expense of a tow truck or being stranded on the roadside, looking for a servo with a jerry can to fill (and who carries one of those around with them these days?).

On some vehicles like the Mazda 3, you could squeeze out another 60-80kms. On a Holden Captiva, you’d be doing well to reach half that distance*.

If your fuel light has come on, don’t push your luck; the farthest distance you should attempt to drive is to the nearest service station!

What Could Happen if I Drive with the Fuel Light On?

Besides running out of fuel, there are other issues when you drive with the fuel light on:

• Your fuel pump could overheat. Petrol acts to cool your fuel pump as it continuously operates to feed fuel to your engine. If there isn’t sufficient fuel in the tank, your fuel pump could fry itself.
• Your diesel-powered engine may not restart. When you run out of diesel, air is introduced into the fuel system. The air bubble blocks the fuel from being injected into the cylinders, causing your engine not to start. The air needs to be bled out and the fuel system primed. It’s a headache with which to contend and can be costly when added to towing fees.

The best practice is to keep your fuel level at a quarter of tank or higher at all times. That way, if you forget to fill up, you’ll have enough in reserve to carry you to the next servo without need for concern.

One of the best ways to improve your car’s fuel efficiency is to regularly maintain your vehicle. So next time you need a service, repair or inspection, visit AutoGuru.com.au. We let you search, compare and book from over 1600 qualified mechanics. Happy days.

* Distances are calculated based on average consumption rates provided by manufacturers and may vary depending on driving conditions, driving style and operating condition of the vehicle.

Service station image by Shell