Just drove from PA to FL, a little over 1000 miles. Kept the speed at +5 over the limit except where 70, then at the limit. Used A/C all the time since it was between 90 and 100. The back of the HiHy was loaded with "stuff". Two people. Got a over 27 MPG average (acceptable). It will be interesting to see what I get on the way back next month for a true average, since historically I get better going from FL to PA. Now for a few observations:

- Cruise control seems to be slightly less efficient than either my or my wife's foot. Both of us felt we could run more often with both ICE and battery than we saw the cruise doing. Of course cruise is MUCH more convenient.

- My HiHy doesn't seem to like 10% methanol fuel. The one tank with 10% methanol resulted in 24.7 MPG vs over 27 MPG without 10% methanol.

- A/C impact on MPG appears to be considerably affected by outside temperature (DUH). We left at 2AM (about 75 but used AC for humidty control) and got an over 31 MPG tank. By then it was about 8AM and subsequent tanks during the day (90+ temps) were about 27 MPG, until we got in FL about 10PM, where the last tank was about 28 MPG (80 temp).

- The HiHY was VERY comfortable for the trip. It rode smoothly, quietly, and easily; not a hard drive. We were able to drive straight through with no problem. We used to have to stop overnight when driving the Chrysler 300M. With the Volvo S80 we drive straight through (gotta admit the Volvos seats are more comfortable than the HiHy - but the two vehicles are designed for completely different tasks).

Anyone have any hints to improve the highway MPG? From what we can see there isn't much other than drive a lot slower (and the subsequent risk isn't acceptable).

 

DWL: Drive With Load. Let the car bleed off speed, when going uphill. Accelerate downhill, to get the speed back. When I'm on the highway, I set a minimum speed, say the speed limit, and try to hit that speed at the peak of a hill. I then gently accelerate down the hill to reach the highest speed I safely can.

The difference you saw, when using cruise control, was probably because you were unknowingly driving with load. Cruise control can't anticipate hills, so your MPG suffers in hilly conditions. Other than that, drive slower, carry less stuff, inflate your tires, bla bla, all the usual stuff.

 

hi

Of all things, we get the best mpg driving on the highway with cruise @ 63mph. We could average about 36mpg. If we bumped it up to 70mpg, we went down to the high twenties.

we live in florida and travel to orlando from palm bay (about 130miles round trip) and that has been our experience. We also crank the AC , then at soonest convience, we push the AC down to bare min power, which has negligible effect on the mpg.

cheers