>Here's something that surprised me but probably was well known to you quants:
>I bought a 2018 Camry Hybrid several months ago.
>This past weekend, to escape from snow and get some golf in, I drove to Santee, South Carolina - about 700 miles each way from here.
>I was also anxious to see what kind of mileage I'd get from the Camry with that kind of driving.
>The Camry has a sensitive meter that tells you what your MPG has been since your last fueling.
>With local driving around here it gets about 35MPG.
>I live about 10 minutes off I95 and my destination is even closer, so this was a straight line drive on the interstate
>The tank has a capacity of about 12 gallons.
>Same fuel - MOBIL regular, all the way.
>On the way down with below average traffic on I95, I averaged about 45 MPG. OK, but not great.
>Coming back though, I learned a bit more.
>I left with a full tank before dawn. Police in South Carolina ignore speeders, so you have to do almost 80MPH to keep up with traffic.
>I noticed almost immediately that my MPG was about 37.
>As I got into NC and VA where police issue summonses at speeds much over 70 MPH, traffic slowed down a bit and my MPG improved a but the overall tank MPG was a disappointing 42.
>I fueled below Richmond, VA and started with a fresh tank and the MPG was about 45 till I reached DC.
>At DC as things slowed down more and the MPG started approaching 48, I decided to try to find an optimal speed.
>
>At between 55 and 60, it got up to 50.8 MPG, while averaging in those earlier higher speeds. Just accelerating a few MPH dropped the MPG almost immediately, but dropping the speed didn't seem to help as much.
>
>When it got up that high, I also noticed that things like elevation changes start to come in to play.
>
>I suspect that with a fresh tank at 55 to 60 on relatively flat roads it would get up to 52 or 53 MPG
>
>Bottom line, speeds over 60 MPH are expensive and speeds over 70 MPH are VERY expensive.
>
>PS - my golf game needs a lot more work.

Probably a combination of wind resistance and gearing. The gearing in most cars seems to be designed to provide best MPG at around 55mph to 60mph. ...and of course the faster you go the more air you have to push out of the way.
I'm on the list to get one of these things www.eliomotors.com -- 84mpg and cost $7450 hehehe. ...I've been on the list for a few years (I was one of the first people) -- we'll see if this darn thing ever makes it to production. They do have ownership of the largest car plant in the USA though -- not to mention 65,000+ reservation holders that have put money down on one. Not easy to put out a new car in the USA these days (Imagine all the regulations and such) -- hopefully they'll pull it off.