The purpose of this test is to see what kind of mileage my 06 HCH will get on my ~27 mile commute (95% freeway) without any input from me; i. e., simply using cruise control. I'm curious to establish a baseline for comparison with hypermiling techniques (pulse & glide) that I'll try next and to see what the car is capable of for the average driver who doesn't use these techniques. I'm also curious about what effect speed has on mileage (with all other factors equal).

The plan is to set the cruise control to 60 on day 1, 70 on day 2, and 80 on day 3. I'll use the same set speed for both the trip to work and home each day.

The particulars of my commute are as follows:

- 27 miles
- Home is 220 feet elevation, work is sea level
- The freeway (CA-85) was constructed to minimize noise to the surrounding neighborhoods, so it's in a sort of trench. It dips down when going under an overpass and rises back up on the otherside (overpass is flat to those crossing it). In other words, lots of ups and downs.

The car had 250 total miles before this test began. Tires are at 32PSI (I'll pump them up to ~40 after this test is complete).

Here are the results for today (60 miles per hour):

Home -> Work

Trip Mileage: 51.4 MPG
Set Speed: 60 miles per hour
Temp: 56 (start), 55 (end)
SoC: 63% (start), 100% (end)
Time: 43 minutes
Notes: At least one bar of regen was showing for the first 6 miles, except when climbing. There was a 5 mile stretch of stop-n-go traffic.

Work -> Home

Trip Mileage: 52.0 MPG
Set Speed: 60 miles per hour
Temp: 64 (start), 55 (end)
SoC: 75% (start), 88% (end)
Time: 34 minutes
Notes: Full speed the whole time (light traffic). At least one bar of regen was showing for the first 20 miles, and the car went into fuel cutoff mode much less than my ride in, although this didn't seem to adversly affect my mileage. I also saw the instant MPG gauge hovering just below 100 MPG for extended (20-30 sec) periods, with the next to last block switching on and off. I've never seen this condition before; normally the guage is very dynamic between 65 and 100, meaning that when it's in this range it's usually on the way up or down rapidly. When it's on the way up, it usually pegs and goes into ICE-off mode.

BTW, now that I am more tuned to the car, I can actually feel the slight vibration difference when the ICE comes back on after being in fuel cutoff mode. It often happens when I'm not looking at the instant MPG gauge and the vibration change alerts me that something has changed. It always causes me to glance at the instant gauge, and sure enough, it's falling off after being pegged. This gives me more confidence that the valves really are sealed when the gauge is pegged. I don't feel it going INTO fuel cutoff mode, however.

Tomorrow, 70 miles per hour.