I've now got 3,500 miles in 2.5 months of driving my HCHII. I love the car, but the inconsistencies are frustrating me! Seems there are times I can do no wrong... accelerating up a gentle slope at 65 mph, look down and I'm getting 55+ mpg on the instant gauge (for MANY miles)!

Other times, I employ every trick in the hypermiling book... and I look down to see a disappointing 40. My overall average has improved significantly since the first tank, and I'm much better at gauging when things will be "good" or "bad"... but there are still mysterious things occurring!

This weekend our family took a trip to San Diego (120 mi. each way). Mileage coming home was awful (for this car, at least!). Got mid 40's. Never went over 60 mph, drove with load over hills, even drafted a truck or two. Just never seemed to find that HMG (HyperMiling Groove)!

Do others find it to be the same way? Sometimes it's easy to get good mileage, other times impossible?

(NOTE: the inconsistencies I refer to are not wind, terrain, load or A/C specific!)