How much gas would it take to drive 140 miles with 23 mpg?

```

Gas (in gallons) = Distance (in miles) / Fuel Efficiency (in mpg)

```

Plugging in the given values, we get:

```

Gas (in gallons) = 140 miles / 23 mpg

Gas (in gallons) ≈ 6.09 gallons

```

Therefore, it would take approximately 6.09 gallons of gas to drive 140 miles with a fuel efficiency of 23 mpg.