gas mileage driving to LA

Day before yesterday, I started driving to LA with my sister, Jovan. We’re in SF now. Since gas is over $4, I decided to take it slow, keeping the cruise control at 60. Most, but not all of the others on the road were faster, but not flying by.I filled the tank whenever we stopped somewhere, first after about 250 miles, and then again after about 200. In both cases, I calculated about 31.5 mpg! The EPA mileage for my car is 20/25 here’s the gov site for that I was pretty stoked. Last time I drove down, I think I got about 27 and I think I was going 65. Let’s say we go 1000 miles. That would mean 37 vs 31.7 gallon. At $.25/gallon, or $157.4 vs $134.9. 16.7 hours vs 15.4