Chipped mileage?

[Mike Del Tergo]

It is interesting to see that cars running virtually identical chip sets 
getting quite varied mileage.
Having had 2 x 200 20V wagons at once, pre chipping one got ~24mpg hwy, 
while the other got ~28 under indentical conditions.  The better mile was 
experinced by the car with 150K while the lower miler ~100K got the lower 
mileage (both kept in good tune).  Overall, it seems that even with a chip 
and a moderate foot, mid 20's hwy is a reasonable target.