2012 smart Fortwo, Hwy vs City street commute?

[zinzarin]

Hi, I'm new to this forum; please be gentle if I break any unwritten rules here.

I have an unmodded 2012 Smart Fortwo, and I've been pondering the question of my commute in regards to fuel efficiency, but I'm not coming to an answer on my own, so I thought I'd ask it here.

I typically drive 65-70 on the highway; I have a OBDII device that alerts me when I exceed 70 or when I accelerate fast or brake hard.

I have three choices of route for my commute to work:
1 (Hwy): 9.5 miles, 7.6 are highway miles
2 (Mix): 8.2 miles, 2.9 are highway miles
3 (City): 8.3 miles, no highway miles

My question seems simple: which route consumes the least fuel?

My thoughts: Route 1 is the longest, but also has the most constant speed. I drive efficiently on the highway (constant speed and not *too* fast). Route 2 is what I think will be best, as it's the shortest but has some efficient highway driving in it. Route 3 is my dark horse, because it's almost as short as 2, and I never exceed ~45 (but it's a lot of stop-and-go, as well).

Thanks for your thoughts!
Rob

[MetroMPG]

Hi Rob -

The Smarts can get decent MPG when driven carefully.

I'd guess that option 1 would return your highest MPG, owing to less stop & go. But the question of whether it consumes the least fuel overall compared to #2 or #3 is another question (longer trip length).

Have you considered getting an OBD gauge (ScanGauge, UltraGauge, etc) that will give you real time mileage feedback? That way you could answer your question through trial and error, PLUS you would have an instrument that helps you fine-tune your driving all the time. Turn your commute into a fun game.

Welcome to the forum!

Darin

[Daox]

Welcome to the site Rob! What kind of mileage are you currently getting with the Fortwo?

Other than that, I'd just be echoing MetroMPG. His advise is spot on.

[vskid3]

How long does each route take? I personally like having my commute as quick as possible.

[oldtamiyaphile]

In my experience, with a small car with poor CD and a small engine with low gearing the City route will win out. Anything above 30mph, and you're burning more than you 'need' to.

If you look at my sig, my first two cars are city only and easily beat EPA, they average ~17mph. The little Fiat does more highway (perhaps 50/50) miles at an average of 30mph, and it doesn't get close.

[Cobb]

Which route has lights vs stop signs? Does a route not have either? Can you make all right turns on a route? Is her ea route that takes you by another destination?

My best route for work takes me past an inconvenience store on my right and I make a right turn to exit it and continue on my way.

Another route takes me by the post office on the right and I make a right turn on my way out.

Another route takes me past walmart and walgreens on the right and has a right turn to continue on my way.

[awcook]

I would guess that #1 would be most efficient if you get over 1.3 MPG better on that trip, then that means that you are saving fuel.

For instance:

Drive 3 miles all city and get 25 MPG vs driving 10 miles highway getting 35 MPG. The highway will use less gas even though it seems like it would use more. If the 3 miles returned 29 MPG, then you will be using less gas driving through the city.

Correct me if I am wrong, but I believe this is how it should work and is how I've been calculating my drives.