As a general rule of thumb, you can expect to need around 20 gallons of gas for a fourteen-hour drive in a passenger car. However, if you are driving a larger vehicle, such as an SUV or a truck, you may need more gas. And if you are driving in hilly or mountainous terrain, you will also need more gas.
To calculate the exact amount of gas you will need, you can use the following formula:
```
Gas required (gallons) = Distance (miles) / MPG (miles per gallon)
```
For example, if you are driving a car that gets 30 MPG and you are planning to drive 420 miles, you will need approximately 14 gallons of gas.
Of course, this is just a rough estimate. The actual amount of gas you need may vary depending on a number of factors. However, this formula can give you a good starting point for planning your trip.
Here are some additional tips for saving gas on a long drive:
* Drive at a steady speed.
* Avoid idling.
* Use cruise control.
* Keep your tires properly inflated.
* Remove unnecessary weight from your vehicle.
* Travel light.
* Carpool or take public transportation if possible.
By following these tips, you can save gas and money on your next long drive.
