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Thinking of getting a prius - Page 12

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Posted by Bob & Holly Wilson on November 3, 2007, 2:56 am

As originally posted, I follow trucks up climb lanes, usually around 55
mph although I've  seen them as low as 45 on I-75 between Knoxville TN
and Lexington KY.

Regardless, Google Earth clearly shows you have confused I-68 in WV with
the significantly higher sections in Maryland. You've been caught again.

Bob Wilson

Posted by Bob & Holly Wilson on November 3, 2007, 3:38 am

I've been wondering about your fixation on I-68 versus Rt. 68, what
you'd originally posted. After a little Google clicking, I discovered
that your fixation is probably on "Sideling Hill Cut," a Maryland, not
West Virgina feature and marvel of engineering. It is the man-made
equivalent of the Grand Canyon in the Appalacians:


One of the earliest photos from this web site shows the three lanes
climbing the grade to "Sideling Hill Cut." The best Prius was to
approach Sideling Hill would be in the right most lane at 55 mph or
behind the slowest truck ascend in the climb lane.

What this does is put the ICE in as efficient of a high power mode as
possible so you are getting excellent conversion of gasoline into
potential energy, altitude. Literally, just keep on truckin' up the

In 1974 after returning from Okinawa, I drove a 66 VW MicroBus from
Coffeyville KS to Headquarters Marine Corps in Washington DC. It is very
likely that I would have taken parts of I-68  and the "National Freeway"
to avoid having to drive the Pennsylvania Turnpike. I vagley remember a
lot of construction but that was a long, long time ago and another
vehicle. I came into the DC area from I-70 and had to figure out the
Pentagon maze.

Fortunately, the same practices that worked with the VW MicroBus work
even better with the Prius. Curiously, the VW also had a 1500 cc engine
and had about as much power as my Prius ICE.

Bob Wilson

Posted by Elmo P. Shagnasty on November 3, 2007, 11:20 am
  bwilson4use@hotmail.com (Bob & Holly Wilson) wrote:

been a dipwad all your life.

We know, Bob/Holly.  We know.

Posted by Elmo P. Shagnasty on November 3, 2007, 11:21 am
  bwilson4use@hotmail.com (Bob & Holly Wilson) wrote:

Nope.  Not at all.

See, there's a VERY big hill--mountain--on I-68 in WV.  The road is a
few miles long.  Trucks go up it very slowly.

And you insist that the trucks go up it at 55mph.

You're a dipwad.  You've never been there, you've never been on a
mountain, yet you continue to make these claims.

Posted by Bob & Holly Wilson on November 3, 2007, 2:30 pm

The slower the better when going up a hill. An efficient Prius driver
simply follows the slow traffic of choice. Interesting, it appears that
some trucks, probably the empties, handle hills rapidly while moving
vans appear to be the slowest. In fact, I look for moving vans, which
makes a lot of sense that they would be relatively slower.

The ride in a truck trailer is fairly rough between the stiff springs
and 90-100+ psi tires. I've had equipment ripped from the rails in a
rack during shipping. Given household moving companies have to pay for
breakage, it makes sense for them to moderate their speeds and minimize
vibration leading to efficient Prius climb speeds.

When trip plannning for a Prius, knowing the heigths along a route
allows making choices between different routes. For example, Google
Earth has a feature that allows you to move the cursor along a route and
read out the heigth:

I-68 in WV highest point on highway: 683 m
39 39' 19.41" N
79 46' 19.47" W

I-68 in MD has a highest point: 853 m
39 41' 23.46" N
79 14' 59.38" W

These are lattitude and longitude in degrees, minutes and seconds. Both
Google and Google Earth allow you to put these coordinates in to read
out the altitude. Topozone works well too. Just use -79 for the
longitude degress for western hemisphere.

When I drove to NC to pickup a spare Prius battery, I drove to Knoxville
and I-40 at a higher Prius speed to get detailed engineering data.
Speeds of 70 mph on the flats with climbs of 55-60 mph on the mountains
gave 50 MPG. On the way back, I took the Interstates to Altanta, doing
an 'end run' around the Smokies at a speeds of 65-68 mph with a fuel
economy of 54 MPG.

BTW, here is some hill climb data that shows the relationship between
climbing speed and efficiency on a 6% grade:

As a general rule, stay below 65 mph on Interstate climbs since they are
typically grade limited to 6%. A 6% grade can be handled all day long
without draining down the battery.

As speeds increase over 65 mph, more and more power is drawn from the
battery and the battery capacity is limited. Once the traction battery
is too low, the Prius will automaticly slow down the car and there are
reports of speeds even lower than 55 mph.

Bob Wilson

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