AUTONEWS

What will happen to the car engine if you run out of gas while driving?

It happens, it's not uncommon...Forget about your worries at work or in your family and you run out of fuel while driving. Can something happen to your car, or can there be major breakdowns?

Car manufacturers claim that their new models are designed so that there will be no problems if you run out of fuel. That is, there should be no engine failures. Despite this, do not wait for the tank to empty, because in that case impurities from the bottom of the tank will also be injected into the system. The fuel filter should take care of them, or prevent them from entering the engine, but it's better not to push your luck.

In older cars, if you run out of fuel, injectors and diesel fuel pumps may fail. In general, always react in time and drive to the nearest gas station.

Who hasn't experienced being behind the wheel and anxiously glancing at the fuel gauge as the needle hovers over empty? Whether it's due to forgetfulness or an effort to squeeze as many miles out of the tank as possible, running out of fuel doesn't do your engine any favors, and it can be detrimental to you as well. A while back, it was reported that a man was found dead after running out of gas in Death Valley. Even if you happen to be in a populated area with services nearby, when your vehicle becomes starved for fuel, it's hard on certain parts.

Gasoline isn't only instrumental in the combustion process, but it also serves to cool certain fuel system components. For instance, the fuel pump (which is responsible for moving gas from the tank to the engine) can start to heat up as you near empty. To function properly, the pump needs a consistent supply of gas. If that supply drops too low, the pump will start moving air instead, which can result in substantial damage.

Why you don’t want to run out of fuel...If you drive a vehicle that runs on petrol, draining your tank dry is bad news for a variety of reasons. Your car’s fuel pump uses fuel as a means of lubrication or cooling, so it can be damaged when there’s no fuel in the system. Your fuel pump will also suck up the last dregs from the very bottom of the tank, which is exactly where any sediment or debris (including, on older cars with metal tanks, rust particles) settle. If you’re lucky you might just end up with a clogged fuel filter, but you could damage the fuel pump.

If you drive a diesel, the dry-tank scenario is even more perilous. While the high-pressure direct-injection set-ups in today’s diesels help them deliver impressive performance and economy, they will not tolerate air getting into the system.

In addition to the risk of damaging your car’s diesel injection pump and fuel injectors – just the latter can cost hundreds of dollars or more each, and your engine has several of them – the whole system will need to be primed to remove all traces of air. That’s means more time (meaning money) in the workshop.

Your car has everything you need to avoid this elemental mistake. At the very least, you have a fuel gauge with a low-fuel warning light, and often a trip computer with a distance-to-empty function, too.

What to do if you run out of fuel...If you have missed all the warning signs and are running really low or out of fuel, there are a few things you should do.

If you drive a diesel, don’t squeeze the last drops out of the tank. If there’s no service station in sight, accept defeat and stop your car while the engine’s still going. Whatever inconvenience you suffer will be insignificant compared with the cost and hassle of letting it run totally dry.

If you have some warning of impending shutdown (such as a spluttering engine), try to move your vehicle to a safe position, well away from traffic. Switch on your hazard lights and, if your car has a warning triangle or some other reflective safety device, place it about 50 metres behind to give fellow motorists plenty of warning.

If you drive a petrol vehicle and have stopped in a familiar or busy area with known fuel supplies nearby, you can walk to a service station and purchase a jerry can that complies with Australian standards.

You will find safety instructions on how to correctly fill a jerry can near the service station bowser. It’s important to place the jerry can on the ground and keep one hand on it while filling to avoid generating static electricity. Also be careful to keep well away from any potential ignition sources and not overfill the can.

Then it’s just a matter of returning to your vehicle and filling your tank – or getting someone to fetch the fuel for you – and you should be on your way. That’s assuming you haven’t ended up with a clogged fuel filter or some other mechanical malady.

Otherwise – and especially if you drive a diesel or are anywhere unfamiliar or remote – you should stay with your vehicle and seek roadside assistance.

This scenario can become even worse if you're driving an older vehicle with many years of debris on the bottom of the fuel tank. As you may imagine, once the pump is desperate to suck up any fuel with a nearly empty tank, that bottom-dwelling sludge can get pulled up into the system and create a clog. According to Kelly Blue Book, to have the fuel pump replaced, you're looking at between $390 and $900, which is certainly not worth delaying a trip to the gas station.

Running out of gas causes the engine to stall immediately due to fuel starvation, but it can also cause severe damage to the fuel pump, which relies on gasoline for cooling and lubrication. The pump may overheat and fail, while the engine can suffer from running "lean," damaging components, and potentially clogging the fuel filter with sediment. 

Key consequences of running out of gas(below):

Fuel pump damage: Modern fuel pumps are inside the tank and cooled by fuel. Running dry can cause them to overheat, suck in air (cavitation), and burn out prematurely.

Engine stalling: The vehicle will stutter and lose power, leading to a complete shutdown.

Catalytic converter damage: If the engine struggles and misfires before stopping, unburned fuel can enter the exhaust, causing the catalytic converter to overheat.

Sediment clogging: Fuel pumps may pull sediment from the bottom of the tank, clogging the fuel filter and injectors.

Loss of power steering/braking: While the car can still stop, the steering wheel will become very stiff and braking will require more effort. 

Tips for prevention(below):

-Avoid letting the fuel level drop below a quarter tank.

-If the car dies, immediately turn off the ignition to prevent further damage to the electric fuel pump.