I would not consider a Honda Insight as a real car its more like a 3 wheeled car with an extra wheel. Thats about as practical as a Citroen 2CV or a 2 cylinder 650 honda micro car and you see about as many as those on the roads these days.
The fantastic almost seemingly impossible mileage I am getting on my car comes with lots of attention to many factors of driving/habits and much focus on efficiency on my part. I never stated that I will definitely reach 1,200 miles on this tank, rather that is is possible, and what it would require to make it a reality. Based on what I know so far I would have to say about 50% of it is driving slow, slower than speed limit whenever possible/safe to do so. 10% = how well maintained vehicle is, filters clean, best fuel quality, right type of oil and 40+ lbs. tire inflation. 10% = never accelerating more than very lightly and upshifting at points like 1-2@ 10 mph, 2-3@ 18 mph, 3-4@ 25-30 mph & 4-5@ 36-42 mph, 10% = coasting to stop lights very early as to maintain as much momentum as possible to minimize downshifts and always using cruise control whenever practical. 10% = warmer temperatures as I clearly see a 20-30% loss in colder temperatures evidenced by very longer warm ups when around 10-20 degrees vs 50-60 degree days, no question effciency is greater on those days. 10% = less clutch slippage and minimization of short trips that do not allow engine to reach operating temp.
I am now at 500 miles on this tank, the needle is at 5/8 left and computer reads 575 to empty & 78 mpg (calculated at about 62-64 mpg) & still climbing, so I expect about 1,000 to 1050 miles this tank and possibly more depending on how may miles past zero to empty I am comfortable driving to. I know I could do 1,200 at least once in the life of this car I'm sure of it.