Originally Posted by Slug

7 miles a day may be a problem. Your first couple of miles are usually using a lot of fuel. And if it'* 3 1/2 miles in the morning and 3 1/2 miles late afternoon, there'* no way you can expect to get much better mpg than what you stated (I think). It takes a mile or two for your car to warm up and become efficient.

Personally (and I may be at odds with the gurus), I wouldn't put a lot of money and effort into car repairs (other than tuning and general maintenence) until you can get some better test conditions for determining city and highway mpg. You can bet manufacturers are using far less extreme conditions for determining city mpg than you are!

Hang in there