Fuel Economy

[swng]

Originally Posted by Silver Streak S

My Yaris has 715 miles on it. I just fueled up today for the 2nd time. I calculated my fuel mileage to be 40.33 mpg around town (no highway driving at all). I drive 21 miles each way to work with avg. speed probably around 45 mph. I have approx 15 stops for traffic lights. I'm not hypermiling but I try to be conservative (no jackrabbit starts, etc.). I'm very pleased so far. Will my fuel mileage increase as my engine gets broken in?

Good numbers!
Hopefully, you will get even better numbers as your car breaks in.
Although you are not hypermiling, you are paying attention not to waste fuel unnecessarily, if this is what you meant in your post. I think that is the main reason why you get reasonably good numbers. As I have been saying, anybody paying attention to F.E and fuel saving techniques will benefit to a degree.
Also, although you said you did not drive on highways, you did say that your average speed was around 45 mph, which I consider faster than the usual speeds we use in city traffic. So, it appears that you have not always been bothered by busy traffic. Also, you said that you drove about 21 miles each way to work, which should be considered a long but quite smooth, albeit non-highway trip. Although you mentioned that there were about 15 traffic light stops each way, you could have been using anticipatory techniques to avoid some traffic light stops some of the time, consciously or otherwise. I think all these contribute to the fact that your Yaris has returned more or less highway fuel economy.
Short trips and bumper to bumper traffic are very damaging to F.E.
I recommend this site to you. It is very practical:http://www.vehicleservice.co.za/calc/fuel.html. Unfortunately it appears that it uses Imperial gallons in its fuel calculator. However, the fuel saving tips in there are good. If you use them, you will not have to rely solely on the car's breaking in to bring you even better F.E.
Warm regards and safe and happy motoring!