Why Do I Get Less MPGs on the Way to Work?

One of the most important steps in MPG enlightenment* is measuring your efficiency over routes you travel most frequently while keeping a running record. You don’t have to go all out and pencil every segment into a notebook (or your smartphone). All it takes to get started is a mental note to your self that says, “hey, I just scored 35.3 MPG on the way to work.” When you travel that same route the next day, try to improve your results. If you do better, you reset the bar. If you fall short, the bar remains in place.

In order to keep track of your mileage by segment, your vehicle must be equipped with an Average Mile Per Gallon (MPG) gauge. You’ll want to reset (zero out) the gauge at the exact same point in your voyage, in order to maintain consistency. To do this most effectively, you should reset just after (or immediately before) your vehicle has left your driveway or parking spot, in order to eliminate the effect of excess idling on the results. The goal of this specific exercise is not to alleviate idling, but to help you become a more efficient driver over the road.

Ideally, you’ll measure your vehicle’s average MPG score from parking space to parking space.

The commute to and from your place of employment may be the most obvious choice for measurement, as you’ll learn the ins-and-outs of that trip like the back of your hand. It’s a good idea to measure each exact route, as there will be differences between the short cut, the easiest route, and the scenic route. The differences in stop lights, stop signs, speed limits, traffic congestion, and elevation changes will have a pronounced effect on the results between specific routes. (Okay, so maybe you should have a notebook or scratch pad.)
If you travel the same route to and from work every day, you will likely see differences between the “to” and the “from” segments.

It should come as no surprise that elevation changes have significant impact. If much of your run is uphill one way and downhill the other, the effect will be clearly demonstrable. When I head into town, a good portion of my route can be uphill … this consumes fuel at an accelerated rate. When I head home, I reap the benefits of gravity, and use inertia as the poor man’s hybrid system … coasting like a bicycle.

You’ll never be able to fully measure these effects without using an Average MPG gauge (of some sort) and resetting before each segment.

The level of traffic congestion is a huge factor and it’s often a wild card over which we may have little control. The primary means is to avoid peak traffic hours. Generally speaking, the more stop-and-go traffic you endure, the lower your mileage results. Most folks need to be at work by a set time, and that impacts traffic levels. You may have more flexibility at the end of the working day. Leaving earlier in the morning and later in the evening can help you to avoid the worst of the traffic, but that’s often easier said than done. They call it Rush Hour for a reason.

That said, one of the primary reasons that your “to” work mileage is poorer than your “from” work mileage is that you’re rushing to work to beat the time clock. A hurried driver is always more inefficient than a relaxed driver. If you leave a wee bit early and take a moment to reset your composure level before you turn the key, you’ll get there safely and efficiently, with less stress to boot.

(*MPG Enlightenment = learning how to use a light foot.)

– by Daniel Gray