I don't know which city you are in, but Dallas has similar conditions. I drive agressively much of the time to stay with the flow too. A number of hybrid Civics get better than my 56.6mpg on my Honda Insight.
I have learned however, that it's possible to go with a fast flow of urban traffic (i.e. somewhat agressive), not get run over, and get 10-15% better fuel economy than when you got the Lexus:
- Anticipate what's ahead
- Try a fast cruise over a lot of stop-and-go
- Consider alternate routes if they are allow more cruising (less strss too)
- Do freeway ramps and approach stop lighta differently
- Above all, refrain from competitive driving. I get weak occasionally try to stay ahead of a particular car - my fuel economy takes the biggest hit. In other words, I'm guilty of this.
If your mpg is 75% of the EPA estimate just remember - if they updated their estimates to reflect today's driving, your driving would be 95% to 100% of their new estimates.
Hope that helps