Is there a google map type service for calculating gas usage?

July 2, 2008 11:24 AM

By using Google maps, I can figure out not just how to get from point A to point B, but also the number of miles and approximate time it would take to get from A to B. Is there a map that will also let me approximate gallons of gas?

Of course, while I can figure out a very rough approximate myself by dividing miles by my car's mpg, the mpg varies by road condition. So driving 50 miles instead of 40 miles doesn't automatically mean that I'm using more gas choosing the 50 mile route.
I'm assuming that when Google Maps (or Mapquest, etc.) gives me an approximate time, there is a database of various posted speed limits on the roads along the route that it is using to calculate estimated arrival time. So is there something that uses posted speed limits, density of cars, number of traffic lights/stop signs, etc., to approximate gallons of gas if I entered my make and year of car?

posted by jujube to computers & internet (9 comments total)

It's not quite as detailed as what you are looking for, but AAA has a fuel cost calculator that takes into account the estimated mpg your car should get, and the average cost of gas in your part of the country.
posted by donajo at 11:41 AM on July 2, 2008

Google does not currently have this feature.

I think offering something like this would be more complicated than we think. Yes, I'm sure Google knows speed limits and has a statistics database of traffic conditions. But there's also the issue of uphill/downhill, and perhaps some other road factors that we can't think of at the moment.

Google would also have to work in the hundreds and hundreds of the most popular vehicles into an MPG database, since different vehicles have largely varying MPGs. (E.g., I think Hummers get ~10 MPG, while Priuses can get around ~50 MPG.) Different people also drive differently - some like to floor the gas pedal once the light turns green, only to slam on the brakes at the red light shortly ahead; others, like me, barely accelerate if they see the red light ahead (which, by the way, saves you both gas and brakes).

In short, even if Google comes up with a service like this, its accuracy, and thus its usefulness, would probably be very limited. With this in mind, I doubt Google will be implementing this anytime soon. Would indeed be a nice feature, though!
posted by ssnickerer at 11:42 AM on July 2, 2008

IME, Google (and everyone else's) predictions of traffic level, approximate time, etc, are unreliable enough that I wouldn't remotely trust them to calculate something as variable as mpg.
posted by Tomorrowful at 11:42 AM on July 2, 2008

Via Google Maps Mania, there's this tool, which gives you directions and expected gasoline cost at the same time. It doesn't take into account the varying conditions along the way, but you can plug in the mpg you expect on that kind of trip.
posted by beagle at 12:17 PM on July 2, 2008

I think if you worked very hard at this you could make a tool to make mileage predictions accurate to ten or fifteen percent --- the estimate is that the 300 mile trip will take ten gallons of gas but it takes nine or eleven. That isn't much different from a typical time estimate ("four-and-a-half or five hours depending on how long lunch takes"), and it's probably about the same uncertainty as your tank-to-tank estimates of your gas mileage. So doing it carefully would be hard and wouldn't gain you much.

The two links already posted are as much sophistication as I would expect to see.
posted by fantabulous timewaster at 1:14 PM on July 2, 2008

beagle - that site is really cool, except it seems to calculate a gallon of gas at $3.20 in it's trip cost calculator...unless I'm missing something.
posted by SampleSize at 1:31 PM on July 2, 2008

Microsoft Streets & Trips has (or had as of 05?) a similar feature. It took into account the type of road (surface street, highway, interstate), a user set speed variable (below speed limit, near speed limit, or above), price of gas, and MPG of your car.

I used the program to print out cycling cue sheets so I don't know how accurate it was. You can probably pick up a prior year's version for cheap somewhere though.
posted by asterisk at 3:23 PM on July 2, 2008

Site is currently down, but Lifehacker just put up this post on DrivePricing which looks pretty awesome.
posted by genial at 1:52 PM on July 9, 2008

DrivePricing
posted by WizKid at 12:35 PM on July 11, 2008