Personally for yourself, you mean? Getting as high as 55 MPG really depends on a lot of factors though. I have had my HCH for about 90 days, and this is the first tank where I have achieved 55+ and I am BARELY over 55 at 55.2 so far. Living in Phoenix, the requirement of using the A/C kills my MPG. This is the first tank I have not had to use the A/C at ALL, and the MPG after 530 miles is looking good. It does take time to learn to nuances of high MPG driving.

My commute is mostly city driving 35-45 mph, about 10 miles one way with two stops, once at the store and once to drop off kids. The PROBLEM is that stopping at the red lights KILLS the MPG in this way: you have to accellerate at a normal pace to get to cruising speed of 35-45 when you leave the red light, and then JUST when you get up to speed you have to start slowing down again if the next light is red. The negative effect of accellerating back to normal speed from a dead stop is greater than the positive effect of coasting/cruising at speed when the distance is only a mile or two.

And you cannot "time" these lights because they are mostly sensor-controlled.

I have noticed that the BEST WAY to get the high MPG numbers is to put the speed at about 36-40 and use the cruise and don't hit the red lights. Great ON PAPER but hard to accomplish. I usually see the realtime MPG meter hovering 60-80 MPG if I can keep the cruise on and speed at that level. But every time I miss a green light, BAM, I'm down in the 20 MPG range again while getting back to cruise speed.

My point is that it is not that easy all the time to achieve 55 MPG....