750 miles Ma to PA round trip with AC @ 68 degrees

That's about right for those speeds.

 

hammy,

what follows is a comparison, not a criticism.

Last weekend we did a similar length trip from Marylad to Long Island, New
York and return. I took a slower speed approach; in 65 MPH PSL zones I did
62; in 60 and 55 I did the PSL. One way I "did it my way," on the other I
used the cruise control. In both cases, I got 59.4 MPG.

I had read here on PriusChat that speeds above 65 MPG would result in a big
MPG hit. So I resolved to drive only as fast as I had to not to be a "rolling"
obstruction to the traffic flow. In comparison with your trip, it's most
interesting to see how speeds above ~60 MPH affect MPGs.

Details on my trip in post #21, here:
http://priuschat.com/forums/fuel-economy/44627-50-mpg-newbies-quest-post663827.html#post663827

Edit: I know that there are many factors that contribute to MPGs including;
weight of occupants and luggage, fuel type, topography, tire pressures, etc.
Thats why I'm not hitting the difference in our MPGs hard. But its interesting to
me that you went about 10% faster, and MPGs were about 10% lower, at or
about 60 MPH.

Oh yeah, I've still got pipe insulation blocks in my upper grill openings.
I saw typical coolant temps ~194 deg F on my ScanGauge. No problemo.

 

hammy, you didn't by any chance go down for a military miniature convention did you?

 

Those MPG numbers sound normal to me, for those speeds, if you have tires at high PSI.

I usually drive faster on the highway, because anything below 72 MPH is dangerous on I-95 near northern VA. I've had some great mileage, 48-52 MPG, even at 75 MPH, on morning commutes. Cars are spaced 40-60 feet apart during rush hour, all while going 70-85 MPH. Thrilling.

I wonder if there is a significant drafting effect while going with the flow of dense traffic on the highway. Has anyone else thought this?

 

nice, About 2 months ago I traveled to MA from NJ a 250 mile trip one way and averaged 54.4 mpg. I was driving from speeds of 60 all the way to 80, I was using the P&G method (who knew it worked as well on the highway!) It was late at night so there were hardly any cars on the road. It was the best mileage I have gotten so far on the highway.

 

Just the other weekend drove from upstate NY to Queens, that's a 160 mile round trip. No ac on, going between 55-58mph, more 55. I stayed in the right lane as much as possible, and finding others in the same lane maintaining the same speed. I guess people are aware now more than ever in how a lower speed effects their mpg's. I averaged 58mpg, not bad considering that I have upgraded to wider tires, and installed mud guards which did decrease the mpg's by a 2-3.

 

Running that close and at times closer to each other and running at 75 mph can result to drafting. Definitely saves some gas on high speeds (just like NASCAR)...but be alert...if someone makes a mistake every car around the vicinity may be affected (just like NASCAR).

 

Great to know as to what I may expect in our upcoming vacation trip. We plan to take the Prius from PA. to Brewster, MA. taking the scenic route. I will try to stay within the speed limit and see what my mpg #'s will look like. If I am close to what you got, I am satisfied.