Understanding the Fuel Reserve
It’s important to understand that when your fuel gauge shows “E,” you’re not actually hitting the true bottom of your tank. Instead, “E” marks the point at which your main fuel supply has been depleted. Most modern vehicles are designed with a fuel reserve, an extra amount of fuel that remains available after your gauge indicates it’s empty. This reserve typically holds around 10% to 15% of the tank’s total capacity, depending on the vehicle’s make and model. On average, a car’s gas tank holds between 12 and 16 gallons of fuel — but larger models, such as trucks and SUVs, naturally hold more.
Manufacturers include this buffer for practical reasons. Most obviously, it helps prevent drivers from running completely dry, even once they’ve hit the empty mark. Running out of fuel will not only leave you stranded, it could also incur more serious repercussions such as a collision. In some cases, the reserve also helps to protect the vehicle’s fuel pump, which can rely on fuel for cooling and lubrication (and replacing a fuel pump can cost about $1,000 to $2,000). The reserve can also help with variations in fuel gauge accuracy and fuel movement while driving — fuel gauges are far from exact, but they do tend to err on the conservative side.
Overall, it’s the fuel reserve that primarily explains why some vehicles can travel surprisingly far after the gauge reads “empty,” while others, in comparison, seem to sputter out almost immediately.
Variables That Affect How Far You Can Drive Below “E”
Several key factors determine how far you can drive after hitting “E,” including vehicle type and tank size. Larger vehicles typically have larger fuel reserves. A full-size SUV might have 2 to 3 gallons in reserve, while a compact car might only have 1 to 1.5 gallons.
Then there are factors that affect fuel consumption in general — and when you’re running on empty, these can be even more consequential. For example, highway driving at steady speeds typically yields better fuel economy than stop-and-go city traffic. The same applies to your driving style: Aggressive acceleration, high speeds, and frequent braking reduce fuel efficiency, while gentle acceleration and maintaining steady speeds can extend your remaining range. Numerous additional factors can play a part, including the weight of your car, how well it’s maintained, the use of cruise control, and the presence (or not) of strong headwinds.
The Real-World Numbers
With all this information in mind, how far can you expect to travel once your gas tank hits empty? Thankfully, there’s plenty of real-world testing and automotive industry data available to answer this question. Tank on Empty, for example, is a crowdsourced database of how far cars can go after the gas warning light comes on. Looking at the data, you can get a sense of what to expect in some of the popular makes and models:
More Interesting Reads
In the United Kingdom, meanwhile, an analysis conducted by Compare the Market found similar results, with drivers having about 50 miles left in their tank on average once the fuel light came on. Of all the cars analyzed, the Toyota Prius had the best reserve range at around 99 miles — being a hybrid model, the combination of electric and fuel power meant the engine used less fuel than a traditional gas-powered car. The Range Rover also performed well, with 73 miles left in the reserve, which can be explained by the Range Rover having the largest fuel tank capacity — 22.7 gallons — of all the cars analyzed.
Interestingly, Compare the Market also found that drivers were surprised by how far they could travel after reaching empty. The distances traveled, in general, were about three times above drivers’ expectations. So once your gas tank hits “E,” you may well be shocked by how far you can still go. But real-world performance can vary significantly depending on a variety of factors, and it’s never recommended to intentionally test these limits. Your safest option is always to fill up as soon as possible once your fuel gauge says it’s empty — or before!