Wednesday, July 17, 2019

Save 35% in Fifteen Minutes!

People will spend 15 minutes to save 15% on car insurance.  Why not do the same to save even more on gas?

The new truck is a technological tour-de-force.   And for the most part it works well.  The passenger side camera seems to have fixed itself, and the left rear tire seems to have stopped leaking, mysteriously.   The car has a number of cameras and sensors.  I moved it the other day, and all the foil window covers were in place.   Not wanting to bother taking those out, I drove it "Birdbox style" by using the external camera view.  It is quite disconcerting.

So far, the truck has averaged about 20 miles per gallon, driving 70-75 miles per hour, going up and down hills in West Virginia, and passing cars (which often means accelerating and decelerating).   Yesterday, in Michigan, we had only 150 miles to go, so we kicked back and set the cruise control at 65 (the truck speed limit) and let the adaptive cruise control "lock on" to a big-rig ahead of us.   By the way, the adaptive cruise control is an interesting beast.   It has some downsides, but for the most part is a big improvement over old systems.   And if the car ahead of you slows down suddenly, well, it throws out the anchor - downshifting to the point where it feels you are going to be flung through the windshield.  Unlike the hamster and the Nissan, it maintains speed going down the hill, as well as up - it does not "run away" like plain old cruise controls.

Anyway, kicking back resulted in an average (for that day) fuel economy of an astounding 27.3 mpg, which frankly, I thought was in error.  That's a 35% improvement in fuel economy.   That's almost as good mileage as the hamster gets.  The Nissan never broke 22 mpg the whole time I had it - and it was a much smaller truck, albeit with a larger (4.0 liter) engine.   But the Nissan was a blunt instrument, relying on displacement to generate horsepower, instead of turbocharging, direct injection, variable valve timing, and whatnot.   Even with only 3.5 liters displacement, the Ford generates 100 more horsepower (365) - and better mileage.

Going slower meant it took longer, of course.   But over our 150 mile journey, the time difference between going 65 miles and hour and 70 miles an hour works out to a little over 15 minutes difference in arrival times.   Factor in your rest stops and whatnot, and chances are, your arrival times may be the same.   But it begs the question, wouldn't you spend 15 minutes to save about 35% ?  We're talking $22.50 of gas at $3 a gallon versus $16.50 at the lower speeds - a savings of over six bucks.   And that's just one days' driving.

I mentioned before in this blog how I drove to Florida in the BMW going 80 mph (which is stupid) and getting mileage in the teens.   On the way back, I slowed down, and mileage shot up to nearly 30.   It isn't hard to do.   At highway speeds, the biggest source of drag is wind resistance, which increases exponentially with speed.   Yes, hills and acceleration use gas, too, but for the most part, they cannot be avoided.   Wind resistance can be reduced, dramatically, by slowing down, just a little bit.   Of course, it helped we were following a truck with the adaptive cruise control, as the wind resistance was reduced in the shadow of that big-rig.

Towing a trailer, of course, we never go very fast.   You're getting crappy mileage as it is with a trailer, and you're more likely to wipe out the whole lashup by speeding and trying to pass, as we learned the hard way.   But maybe from now on, I won't be trying to play beat-the-clock.

And it is hard to do - as so many people get "caught up" in traffic as if it was some kind of race or another, and that beating the guy ahead of you to the stoplight is the most important thing in the world.   But it is funnier to pull up next to the guy who just "had to pass" you earlier, at the next stoplight - arriving at the same effective time, with an extra gallon in your tank.

UPDATE:  Our mileage was not a fluke.   Yesterday we averaged over 25 MPG and today over 24 (no trucks to follow!).  Five MPH slower means five MPG more!