[SentraSE-R]

I did a real-world back-to-back 150 mile round-trip drive with and without 200 kg of additional (3 adult) passengers. The trip was from Bryce Canyon National Park (8000' elevation) to Hell's Backbone Grill in Boulder, UT (6700' elevation). The 1300' elevation drop doesn't give a good picture of the multiple uphills and downhills, including a couple of 12 and 14% grades that had me geared down to second gear. The trip takes you on a hogback with 1500' drops on both sides - one of those helicopter photo-ops for sports car advertisements.

The first trip was on a Monday afternoon and evening, driving four of us to dinner. I got about 50 mpg on the way to dinner, and 42.7 mpg for the round-trip. Conditions weren't ideal, as I had to run the AC occasionally on the drive out, and drove home with the lights on. I probably took a 5% hit on mileage that trip.

Two days later, I repeated the drive alone, under near-ideal conditions. I averaged 140 mpg for the first dozen miles, an amazing 71.9 mpg for the first 48 miles to Escalante, and 55 mpg to the restaurant. Overall, I averaged 47.5 mpg for the low weight round-trip. My mpg difference for the two trips is about 10%. Obviously, there's too much experimental error to come to any conclusions, but I got 170 people miles/gallon taking us to and from dinner, and had a gorgeous scenic drive on the repeat trip.