Okay, I just got back after my first drive cross country of the year
(Washington DC, to Tacoma, Washington. This was in my Westy Syncro with
a stock 2.1 liter engine, 15" wheels and 215/75R15 tires.

Some observations. The grades in Wyoming were the ones that bogged me
down the most (once I had to drop down into 2nd gear)...mostly I had to
shift down to 3rd gear...rarely could I stay in 4th...on the grades. On
level ground I usually was driving at around 78 mph (75 indicated on
the speedo, but the larger tires bump it up a bit as indicated on the
GPS.)

The road grades going up might be LONGER than West Virginia roads, but
they aren't steeper.

I got about 15 mpg on the first 2 days (Kentucky and Missouri)...until
I realized my air filter was cruddy. Cleaned it out (K&N) thoroughly in
Kansas...In Kansas I could only maintain about 65 mph due to the very
gradual incline (you climb 3500 feet from central Kansas to Denver).
After cleaning I was back up around 17 mpg.

Saw a couple of Vanagons in Colorado. Saw a LOT more in the state of
Washington (especially in the Tacoma/Seattle corridor).

Tetons were more impressive than I realized from photos. Yellowstone
sucks when it rains (as it did for me on this trip. Red Rock Wildlife
Preserve was an unexpected surprise (lots of bird wildlife, if you are
in to birding.) Camping at Lake Kachese (Washingont) was great.
Crescent Lake in Olympic National Park was awesome.

In general, Washington roads are horrible (not pot-holed or anything,
but extremely rough and noisy.) I also managed to be in Washington
during a record setting heat wave (90+ degrees). Felt pretty normal to
me, except for lower humidity.

My return trip will be in about 4 weeks...and it will be a Subaru
Powered Westy then.