I'm not an owner yet but I've been surfing to figure out if I want to take the plunge.

One of the things I keep hearing is that mileage gets better with time. Some have said that the friction in the engine gets less and it is more efficient. I decided to do a simple test.

I took the Prius and the Lexus 400h data for all inputs that had one or more tanks of fuel used. I plotted the mpg versus the mileage, ran linear and power trend lines to see if the the mpg was correlated with the mileage.

R2 measures were no better than 0.15, which is very poor.

My theory is that is is driver dependent. Some pick up the tricks easier than others. Some can't realize that hybrids (at least now) are not just more efficient gas engine cars. I you drive them efficiently, you can get good mileage. If you had bad habits that drove you old car down, you'll find it will do the same in a hybrid.

Since you guys (ladies) are the experts actually having an RX400H, what do you think? How hard was it to change your habits? I drive 30 miles RT in stop and go LA FWY traffic; what do you think I should expect from a Lexus RX400H?