Is It Bad To Run Your Vehicle When It’s Low On Fuel?

There's nothing worse than jumping in your car when you’re running late for work and seeing the dreaded fuel light come on. Cursing your past self who said, ‘I'll fill up tomorrow morning on the way to work’ but then proceeded to stay up into the early hours binge-watching ‘The Office’ for the 15th time, you wonder if you can risk driving without stopping.

Running out of fuel is one of the worst experiences you can have as a vehicle owner, but it’s almost a rite of passage for it to happen at least once in your motoring lifetime. But can it cause damage to your vehicle or just your ego? This blog post dives into the potential risks of running your vehicle low on fuel, especially for eco-conscious drivers looking to maintain their vehicle’s longevity and efficiency.

Understanding Your Fuel System

First, we need to look at the fuel system and understand how it works. On modern fuel-injected vehicles, both petrol and diesel, the main fuel pump is located inside the fuel tank. It is situated almost at the bottom point of the tank, usually in a swirl pot or fitted inside a Modular Reserve Assembly (MRA) unit. These units are designed to keep the fuel pump submerged at all times as the fuel acts as a cooling and lubricating system to keep the pump operational.

The Risk of Running Dry

When the tank is dry, the pump runs without lubrication or cooling, which can cause damage over time. While it may not cause the pump to fail if it happens once, running the pump dry multiple times will cause it to overheat and fail, and replacement is the only option. This is particularly concerning for eco-conscious drivers who want to avoid unnecessary repairs and replacements.

Older Vehicles and Sediment Issues

On older vehicles, the fuel tank was made from pressed metal. Constant contact with petrol and other contaminants would cause the inside of the tank to rust away with sediment settling down near the fuel pump. When the fuel tank is near empty, this sediment tends to be picked up by the fuel pump and can damage the internals of the pump and clog the fuel filter. When this happens, replacement of the fuel pump and filter, as well as cleaning out or replacing the fuel tank, are the only options to get you back on the road.

Modern Fuel Tanks – A Mixed Blessing

Thankfully, most fuel tanks these days are made from plastic, which has greatly reduced the issue of rust and sediment. However, sediment can still be present from contaminated fuel, poorly sealed fuel caps, and various other sources. It’s best to keep an eye on the fuel level and refill before the fuel light comes on to avoid these potential problems.

Diesel Engines – A Special Case

If you have a diesel vehicle, running low or out of fuel can be a much more troublesome experience. Due to the high pressures associated with diesel fuel injection, running the fuel pump and lines dry can cause expensive damage to both the diesel injection pump and the diesel injectors. Once the fuel tank has been filled again, the whole fuel system must be primed to remove all traces of air; otherwise, poor running, stalling, and other issues can arise.

Manufacturer Recommendations

Most manufacturers recommend refuelling the vehicle once the needle goes below ¼ on the fuel gauge. This is a good practice to prevent the potential issues mentioned earlier and to ensure your vehicle runs smoothly and efficiently.

Think about those times you’ve noticed the fuel gauge reading near empty but you’re already pulling into your driveway for the night. It might be tempting to leave it for the morning, but getting up early enough to leave yourself time to carry out this essential chore can save you from a lot of trouble.

Staying up till the early hours watching The Office may be fun, but it isn’t a laughing matter when you’re not only late for work but conked out on the side of the highway. The costs of running out of fuel are not just about inconvenience; they can also lead to expensive repairs and replacements.

Tips for Eco-Conscious Drivers

For eco-conscious drivers, maintaining your vehicle’s fuel system is crucial. Here are some tips to help you:

• Refuel Early – Don’t wait for the fuel light to come on. Try to keep your tank at least ¼ full at all times.

• Use Quality Fuel – Use well-known fuel brands to avoid contaminants that can cause sediment build-up.

• Regular Maintenance – Regularly check and replace your fuel filters to keep your system clean.

Simple practices like maintaining steady speeds, reducing unnecessary weight, and regular servicing can significantly improve your fuel efficiency.

When you do go to fuel up, make sure you've got one of these apps that helps you find the right fuel price in your area, saving you money in the long run.

Running your vehicle low on fuel can be bad, especially if you run it completely dry. It’s not just about avoiding the inconvenience of running out of fuel; it’s about protecting your vehicle from potential damage and maintaining its efficiency. This is especially important to ensure that your vehicle remains in top condition while minimising your environmental impact.

Next time you notice the fuel gauge is low, think about heading back out to the service station. Alternatively, plan ahead and make sure you have enough time to refuel before starting your day. It’s a small effort that can make a big difference in the long run.

For more tips and advice on maintaining your vehicle and improving fuel efficiency explore our blog and stay informed. Happy driving!