MPG is not so important

[actwithclarity]

Imagine you are going from point A to B with 2 routes to pick from. Route X is 50 miles and you can get 50 MPG. Route Y is 60 miles but you can get 57 MPG.

What route should you take?

Route X will cost 1.00 gallon of fuel.
Route Y will cost 1.05 gallons of fuel.

Even if you care about fuel efficiency above all else, MPG is just a vague number that should be taken with a grain of salt. It is only useful as an absolute statistic if you are driving on a set route.

Other than total fuel cost, factors that people may want to consider include: time, vehicle wear, mental health, scenery, etc. The best thing you can hope to do is weigh the factors and make an intuitive guess on the best route. MPG should not be the primary goal unless you're some sort of whacko.

Something I often have to face is driving through the city, or taking a highway that goes around the city. I know that MPG will probably be better on the highway, but straight through the city is a much shorter route, so total fuel cost will be cheaper that way. However the city also takes 20 min longer (if I'm going all the way across) and has some annoyances of city driving. In the end this decision however comes down to TIME. If I'm being paid by employer, I'll go through the city to save fuel cost (I don't get paid fuel) and maybe even to burn some extra time. If I'm on my own time I'll usually go on the highway because it saves time and gives me more peace of mind. Maybe there is more I should consider, I'm not entirely sure that was just my best guess so far.

[Frank Lee]

Originally Posted by actwithclarity

Even if you care about fuel efficiency above all else, MPG is just a vague number that should be taken with a grain of salt. It is only useful as an absolute statistic if you are driving on a set route.

Not so. It provides the driver with a benchmark to try to surpass, regardless of route. It also can provide the driver with an indicator of the vehicle's state of tune- if the gaslog shows a sudden variation that is otherwise unexplainable, it is prudent to go give the vehicle a check-up. And of course it provides a figure to compare one's own performance with that of others.

[actwithclarity]

I guess you're right about it being a benchmark. However it seems slightly ironic to use more fuel for the sake of improving your MPG. As long as people understand that making MPG a primary goal at some point makes it no longer related to fuel cost, I suppose it's fine to pursue for the sake of making driving more interesting.

[shovel]

There are tons of people playing with ecomodding and everyone has their own reasons. For a lot of us it's just something to tinker with, because we're not satisfied by tv. It's something to chat about with other people, innovations that work end up feeling rewarding, even if they don't otherwise mean much in the grand scheme of things.

And as a broader benefit, every once in a while someone stumbles on a new & functional innovation that spreads around and potentially creeps into the market, potentially creeps into new vehicles in some form - every feature of a modern car came from this sort of tomfoolery, whether on the clock or in someone's garage decades before it made its way into production.

So your initial post makes some valid points, but they don't invalidate the stuff we do here

[dcb]

Like it or not, most people are basically on a set route during commuting, and don't do a whole lot of research about which route uses the least gas (or which route enables the most gas saving technique even). Similarly, you do not see a lot of people seeking out the most efficient route to the store and back, or to piano lessons or whatever. So MPG is simply a measure of efficiency of the driver/vehicle overall, not a measure on how good a route planner they are.

You absolutely can use raw fuel consumed to locate the best route between two points with some trial and error. Keep in mind that the best route may change as your hypermiling skills change and equipment gets modded, but yes the bottom line is how much fuel did you use to get from point a to point b.

If any driving is jeopardizing your mental health, then you should chill. Don't be in such a rush that you go wacko over the slightest obstacle. Most times folks have to slam on the brakes is due to bad planning (and braking is not efficient). And as you learn what hypermiling actually is, don't be surprised if you find yourself saying the exact opposite of this "I know that MPG will probably be better on the highway". My cars have not been aeromodded enough where I do better on the hiway than in the city.

[Kodak]

AWC - I think you have some legitimate concepts. There are certainly other things to consider when choosing a route of travel.

And I definitely agree with you on your criticism of mpg as a measure of fuel consumption; it really measures fuel economy. Fuel consumption is more important from a financial standpoint, so what you really want is: total gallons route A versus total gallons route B. So, as long as you know the distances of both optional routes - and a good estimate of mpg for both routes - you can easily calculate which is the cheaper route.

But in the grand scheme of things, hypermiling does create somewhat of a different mindset on the road, which can carry over to most any driving situation. Basic stuff like anticipating red lights, not following too closely and following the speed limit all transfer to any commute.

[gasstingy]

AWC, I agree in some respects to MPG not being too important. We all make choices on our driving habits. I can look at my fuel log and see the results of tradeoffs I've made when driving.

If something important comes up and I'm pressed for time {or the wife is really anxious to get somewhere} my mileage suffers. Just about a week and a half ago, I found myself just ahead of a large tornado coming my way. When I realized how close it was, I can assure you, MPG became the last of my concerns.

FWIW, I do find the process of trying for the best MPG to be worth it or I wouldn't do it. I like the challenge of trying to beat my average as I try to improve. I can also say that my driving is far less stressful now that time travelled, or speed through a curve is no longer my top priority. I don't flinch and automatically hit the brakes any more when I meet a police cruiser. I hope you give it a fair try before you dismiss it as not worth your time. But if you choose to disregard this driving style, you are free to do that too.

[Ryland]

Can't the scan gauge give you a trip cost, or fuel used per trip?
I agree that we should not only be looking at more miles per gallon but also fewer miles, after all that is the first suggestion that alot of people are given if they are driving 200 miles per day is to change jobs or move, if you are driving short distances where your car never warms up then bike or walk! I don't like buying gas more then once per month, sure I like getting more miles per gallon but if I go over a month without buying gas then I'm just as happy.

[PaleMelanesian]

I agree that lower total fuel consumption is the end goal.

I keep detailed records of my drives with the route, distance, mpg and calculated fuel consumed. I know that my chosen route, while being slightly longer, uses less fuel than the shorter route. It also gives me a double-bonus for mpg - higher miles for lower gallons. That's nice, but lower gallons is the real benefit to my wallet, the environment, the political world, etc.

[Doofus McFancypants]

i have this situation with my commute. I can take surface streets (( aren't almost all streets really surface streets)) travel 12 miles and consume 0.38 gallons of fuel at about 31.5 MPG (about 25 min commute time). or i can take the highway and travel 14 miles with consumption of 0.4 gallons resulting in about 35 MPG (about 18 min commute time).

Unless time is an issue - i avoid the highway. Granted 0.02 gallons is really tiny but those are $$ i am spending to travel between the same points. (0.04 Gal / day * 5 days / week * 50 weeks / year * $4 / gal = $40 / year )

As a secondary consideration - Atlanta traffic can go really bad really fast - so I stay away from highway.

So i have taken both aspects (total fuel used and best MPG).

Steve