Do left turns lower mpg?

[GasSavers_jkandell]

Is it a good rule-of-thumb to eliminate left turns if you can? I'm trying to think of my typical routes, and am not sure whether driving around the block (turning right) would use less gas than waiting and then turning left... What do you all think?

[SVOboy]

They do suck! I would try to limit any part of your commute that includes forced stops.

Nice scoot in the avatar, by the way.

[MetroMPG]

If you shut the engine down while waiting for an opening, I'd say that would be most efficient.

Even if you left it running, I doubt you'd save fuel going around the block doing right turns.

[Silveredwings]

UPS thinks so: http://multichannelmerchant.com/opsa...fuel_conserve/

[GasSavers_DaX]

I don't avoid left turns. I judge each turn individually, and as early as possible. If I see a possible opening coming up, I keep the engine running and time the gap. If it looks like I won't be able to make the turn without stopping, I turn the car off as early as possible (enough momentum to get to the stopping point), then either clutch start the car if I'm still rolling by the time I get there or crank the car if I have come to a rest.

[ELF]

Originally Posted by DaX

I don't avoid left turns. I judge each turn individually, and as early as possible. If I see a possible opening coming up, I keep the engine running and time the gap. If it looks like I won't be able to make the turn without stopping, I turn the car off as early as possible (enough momentum to get to the stopping point), then either clutch start the car if I'm still rolling by the time I get there or crank the car if I have come to a rest.

Pretty much exactly what I do.

[GasSavers_jkandell]

Originally Posted by SVOboy

Nice scoot in the avatar, by the way.

Alas, this very scoot (an orange Stella) is sitting in my garage damaged after being hit from the rear at a stop light. I'm lucky to be alive, so, my scooter days are over. I'm now riding a Honda Fit--six airbags. In fact, I joinsted this site somewhat from guilt at having to own an auto. I want to at least beat the epa! The stellas are great though--they're modern replicas made in India at a plant that used to make 80s vespas. (Very hypermiler: why pay for a prestigious badge just to be cool?) And they're manuals, so you can coast like crazy.

[GasSavers_jkandell]

Originally Posted by Silveredwings

UPS thinks so: http://multichannelmerchant.com/opsa...fuel_conserve/

I wonder what the actual formula is, since there is a "break even" point in distance where turning right uses more gas than "idling" while waiting to turn left.

[SVOboy]

The Stella is made by Buddy? I think I saw one for sale at a forum I'm on the other day.

You should be able to do well with the Fit, I'll be looking forward to seeing your progress!

[brettds]

Originally Posted by jkandell

I wonder what the actual formula is, since there is a "break even" point in distance where turning right uses more gas than "idling" while waiting to turn left.

I think it's a little different for UPS than for someone commuting to work. The UPS drivers make multiple stops, so the software essentially tries to make the route into as much of a circle as possible, and it tries to plan it such that you can make right turns as much as possible.

While it is possible to optimize a route between two locations to use right turns wherever possible, it's a lot less flexible than when you have to make 50 or 100 stops.

I highly doubt the software would tell you to go around a block making three right hand turns instead of a single left, and I would imagine that there are very few situations where that would be more effecient.

Brett