Improving Gas Mileage (pt 2)

Over the past months, I’ve used a Linear Logic ScanGaugeII in review cars lacking a built-in real-time fuel economy gauge. While I’ve achieved some pretty good results, there’s no magic to what I do … it’s simply a matter of driving conscientiously.

There’s little doubt that you can save a remarkable amount of fuel if you just put your mind to the task. Like so many things in life, if you don’t pay attention to the details, it will cost you …

It took me a little while to figure out which ScanGaugeII functions were most beneficial for improving gas mileage results. As of this writing, my favorite combination is the RPM (revolutions per minute), real-time MPG, TPS (throttle position sensor), and GPH (gallons per hour) read outs. Seeing these four gauges in one glance gives me the handle on how much fuel is running through the engine at any given moment.

Last week, I had the opportunity to put the ScanGaugeII to the test in my wife’s 2003 Honda Pilot, on a highway run to the airport and back.

Shortly before heading out, I popped the ScanGauge’s plug into the Pilot’s OBDII port, snaked the cable around the steering wheel column, and found the perfect spot for the unit in a cubby hole underneath the HVAC controls in the center of the Pilot’s dash.

Our 8-seat Pilot has been ridden hard and put up wet for most of its life. But with over 130,000 miles on the clock, it’s paid off and owes us little. We ran the test just days after the Pilot received a fresh set of Yokohama Geolander tires, a four-wheel alignment, and an oil change (it’s first in quite some time). As the trip progressed, the numbers kept going up and up (and the air conditioning was on for a good part of the voyage).

We were absolutely blown away by the mileage results, with an average of 31.5 MPG on the highway, on both legs of the trip.

Thinking the numbers were a fluke, we kept the ScanGaugeII in the Pilot for our weekly beach trip days later. We were amazed to archive similar results. While our trip down to the shore averaged just under 30 MPG, the trip back home came in at just over 31 MPG, over rural highways.

These figures are remarkably better than the official estimates (17 city/22 highway) for a 2003 Pilot. Over the course of a year with 20000 highway miles and an average gas price of $4.00 per gallon, this technique could save more than a thousand dollars in fuel costs.

In the accompanying video, you’ll see a short evening sequence I shot that documents the technique used to improve gas mileage. It’s not hypermiling, by any means. It’s just a very measured application of throttle, when and where needed.

It’s worth noting that the real-time MPG data will vary. That is to be expected. You cannot and should not depend on the instantaneous display to be 100% accurate. Instead, you use the data to alter your driving techniques and improve your gas mileage. This will be shown by the average MPG, and more importantly, by the actual number of gallons pumped into the tank at each fill up.

In other words, you still need to do some math …

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6 thoughts on “Improving Gas Mileage (pt 2)”

  1. The RPMs displayed seem to be pretty inconsistent with the gauge in the dash. I really like the throttle position indicator. I bet this would pay for itself pretty quickly.

  2. Thanks for the demo. But, I’m wondering, how does the average MPG estimated by the ScanGauge compare with reality? What’s missing from your test is a validation step comparing how many gallons of gas you needed to refill your tank after your test.

  3. Fear not, the validation step for the 130K Pilot is on the list of things to do. There are a number of variables, most importantly “how full is full?” We try to use the same pump, whenever possible.

  4. Nice, but what about those of us who drive cars that were made before 1996? We have OBD I, but those engine computers don’t keep track of so many variables, so perhaps a vacuum gauge can be used?

  5. Although less sensitive, I just look at the rpm guage on my car to help gauge and use least amount on throttle needed for speed to get better mpg. Downhill on neutral, can see the revs drop below what it would be in gear.

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