165/20 mpg = 8.25 gal
165/17 = 9.70 gal

9.70-8.25 = 1.45 gal

1.45 gal * 1.89 per gal = $2.75

165/50 mph = 3.3 hours

3.3 – 3.0 = 0.3 hours

60/10 = 6 minutes in 0.1 hours

18 minutes in 0.3 hours

So $2.74 or 2.75 more and 18 minutes longer .

but in real life, you dont think about this, it isnt worth it to have 5 dogs AND a wife howling