Route conundrum...
 

I'm new to eco driving... I hope someone can advise me. I drive pretty much the same route every day. There are many ways I can take to bypass traffic but only 2 ways I can get home from the freeway. One route is longer but doesn't have any traffic lights or hills. The other route is shorter has 4 extra lights (which are horridly timed!), a slight uphill grade and a rather large hill.

It might be an easy question but the shorter route is actually 3.5 miles shorter...If I get stuck at every light (which happens about 50% of the time) both routes take about the same time to complete. I'm hoping there is a way to take this in to account. I don't have anything to tell me instant MPG.


My question is how can I figure out if taking the long way is actually worth it or not?

I just did both routes and calculated FE at the end of each tank. I wish for me it was better to go to the highway, but the lower FE i get in city driving compared to Highway does not offset the difference of the actual miles.
The 2 ways for you would be to do it this way or hook up an MPGuino to your car to get the trip mpgs

Thanks for the reply :)

I was hoping to avoid driving the route for a full tank because of the error factor. I would have to drive the new route for several tanks to get the average which could take a long time and potentially waste fuel if it isn't "worth it" :(

I've read some of the MPGuino information and it seems like a cool gadget. However I have made a strict rule (to myself) that any eco mods I do would need to be justified by a ROI. For example currently if my vacuum gauge (driver mod) continues to net me +3 MPG it would take about 7 fill ups (about 2 months) to pay for itself. I know nothing ventured nothing gained but being broke sucks.

I paid $70 for my ultragauge and have already seen a full ROI. The problem with a vacuum gauge is its instant feedback. what we do with the gauges scangauge, ultragauge, mpguino is play a game where your avg fuel economy is your score and always trying to get the high score by keeping your foot off the pedal. It gets quite fun trying to beat your previous tanks. Scangauge and ultragauge are obdII though

I see what you are saying.

I have an app on my phone that tells me average speed... you think there would be a way to calculate which route is more efficient by that?

i say no for the reason being to get good mileage you want to be as slow as possible in the highest gear. Ie. i can already tell you city is going to be slower, but for most people highway gives better mileage. Now some people on here can get better mileage in the city versus highway as for the techniques used.

I have no doubt I would get better fuel economy going the long way but that also means about 35 miles extra per tank...

I figure if I used the exact same fuel going either route and I get 25MPG going the shorter route does that mean I have to get greater than 28MPG in order to actually save money?

does that sound right?

I nearly always choose the longer, but non-stop, routing.

Whether in my pickup or at work in the Peterbilt. FE is really just a way of showing lower fuel burn for the same work accomplished. In this instance -- routing -- the stop'n'go is detrimental to the rest of the vehicle (non-steady fluid temps, tire temps, etc) and requires more inputs from the driver.

Thus, while I travel a bit farther (there is a trade-off of miles versus savings at some point) I feel assured that the fewer stops/accelerations is the best course to take for longest vehicle life. And for the driver to retain as much energy as possible (this is not discussed, but vital to more than FE, it is central to safety).

That is the larger metric over FE -- vehicle longevity -- and the one that really counts. Once the vehicle is broken-in, we do not want any degradation from that point onwards. Longest life in tires, brakes, etc, is directly to that end as well.

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I see what you are saying. I was hoping there would be some formula or rule of thumb... I think I will try taking the other route for a few weeks and see what sort of improvement there is. 17.5 extra miles per week isn't huge but could actually cost me in the end.

I also vote for the low-stress longer path. No hills? Fun.

Can you describe the paths a bit more? You say it's 3.5miles shorter, over what distance? What speeds? Just accelerating from a couple lights would negate any MPG gains from the shorter commute, IMO.