Most of my driving is on rural roads, but last weekend I took a trip to Philly which involved 95% highway driving. With A/C blasting I averaged 72 mpg in my MT Insight. I know this is not much for the hypermilers, but I am really happy
Experience is showing me that these Insights do indeed "shine" on the highway runs; i.e., somewhere about ten to twenty miles or better. Yesterday, after a bit more than a twenty five mile run, the MPG was 65.1 for the day.
As for those rural dirt roads, which we have a lot of here in the resort areas, experience is showing me that the only way to come close to keeping the MPG up, is to slow the car down; twenty to thirty MPH or so.