```
Cost of fuel = (Distance traveled in miles / Miles per gallon) * Cost of fuel per gallon
```
In this case, the distance traveled is 1650 miles, the miles per gallon is 23, and the cost of fuel per gallon is $4. Plugging these values into the formula, we get:
```
Cost of fuel = (1650 miles / 23 miles per gallon) * $4 per gallon
```
```
Cost of fuel = 71.74 gallons * $4 per gallon
```
```
Cost of fuel = $286.96
```
So, the cost of fuel to drive 1650 miles with fuel at $4 per gallon and a fuel efficiency of 23 miles per gallon would be approximately $286.96.