Image: Rohane Hamilton Image: Rohane Hamilton Bing! The gas warning light illuminates and your thirsty car is demanding refreshment. "Time to fill up," it says, forcing you to find the nearest gas station and lay down some cash for a refill. But what if you could tell exactly how much further you could go? You might be able to finish up your commute or complete your errands without having to visit the pump. Or perhaps you're on a road trip; can you make the next rest stop? A Personalized Approach 2025 MINI Cooper S 4 Door: All the Details how far can you drive on empty A rough estimate isn't too hard to come by, but it will need some calculating, so get ready to do some grade six-level math. First, take a look at your vehicle's technical specifications. This can usually be found in the owner's manual. Usually listed near the size of the gas tank is specifications for reserve fuel. In most vehicles, when the fuel level reaches the reserve fuel level, the gas warning light pops up. There's no standard for how big the fuel tank reserve is, but most of the time it's about 10-15 percent of the overall size of the tank. You can then use that information, as well as your car's average fuel consumption information, to see how far you have to go. In most cars, the low-fuel light generally comes on when you have less than 50 miles of fuel range left. Image: Consumer Reports Image: Consumer Reports Let's look at the case of the 2026 Honda Civic Sedan. Its fuel tank capacity is 12.4 gallons for non-hybrid models and 10.6 gallons for the hybrid versions-so 10 percent of that is about 1.2 gallons. If you multiply that by the car's 36 mpg rating in combined driving conditions, you get 43.2, so you can likely get an additional 43 miles from your car after the warning comes on. Luckily, most modern cars offer a distance to empty function, which uses the vehicle's observed fuel economy to calculate the distance available in real time so you won't have to do the mental math while hurtling down the freeway. A careful note of caution, constantly running your car off its reserve fuel tank may cause damage to your vehicle's fuel pump. Armed with this information, those with range anxiety should be put at ease. Take into consideration driving habits which can greatly affect your fuel economy and you shouldn't be caught off-guard by that fuel-warning light again. This means that if your fuel warning light comes on, you should be able to finish up your errands or commute home, and refuel when it's convenient. 2026 Chevrolet Silverado EV Trail Boss: All the Details