Finally figured out P&G, what a boost!

[Danny Hamilton]

Originally Posted by F8L

. . . .Finding alternative routes helps a lot as well but one must consider actual distance traveled because adding miles to a trip just to increase mpg is not very eco-friendly.

Adding miles to a trip to increase MPG may or may not be eco-friendly. It depends on how many miles are added, and how much MPG is improved.

Example:

30 mile drive getting 46.5 MPG = 0.645 gal.

alternate route:
35 mile drive getting 60 MPG = 0.583 gal.

Alternate route adds 5 miles but saves 0.062 gal each way.

2 times per day 5 days per week 52 weeks per year:

0.062 X 2 X 5 X 52 = 32.24
5 X 2 X 5 X 52 = 2,600

Under these circumstances driving an extra 2,600 miles saves 32.24 gallons per year.

Also at $4.00/gal that's $128.96 saved.

Of course while the addition of 5 miles per day may be eco-friendly in this case, if it meant driving significantly slower you'd be giving up quite a bit of time to save that fuel and money.

30 miles @ 70 MPH = 00:25:42.857 per trip.
2 times per day 5 days per week for 52 weeks = 9 days 6 hrs. 51 min. 25 sec. total per year

35 miles @ 40 MPH = 00:52:30.000 per trip
2 times per day 5 days per week for 52 weeks = 18 days 23 hours. total per year

That's an increase of 00:26:47.123 per trip or 9 days 16 hrs. 8 min. 35 sec. per year

On a purely short term personal financial cost/benefit analysis, it wouldn't likely be worth it. On the other hand, if you enjoy the challenge or feel strongly about the environmental benefits, it could tip the scale.

[JimboK]

Originally Posted by F8L

I think that most city streets can utilize a form of this technique.

You are spot-on. I think some folks reject P&G out of hand because, at a minimum, they don't want to disrupt the flow of traffic or be discourteous to those behind them. Those are valid concerns, and many won't have the opportunity for sustained P&G on their typical routes without inciting road rage or being unsafe.

But we all accelerate and decelerate. Why not do both as efficiently as possible? When you accelerate (the pulse), avoid drawing from the battery or pushing ICE RPM into inefficiently high ranges. When you decelerate (the glide), preserve as much kinetic energy as possible instead of wasting it.

With anticipation of lights and other slowdowns and a little practice, I think folks (in any vehicle) would surprise themselves with fuel economy improvements just by being efficient during times they're speeding up or slowing down anyway. Then as the technique becomes more ingrained, it can be called up on demand for more driving segments as conditions and operator temperament allow. It might be just for a short segment as traffic volume behind temporarily drops. Or it could be something more sustained on lightly traveled streets. Finally, many can find alternative routes that provide more and longer P&G opportunities. Heck, they might even find the alternatives to be shorter overall for an even greater fuel savings.

[Prudence]

Originally Posted by a priori

Really, I just drive cautiously and always look ahead to try to keep room ahead of me for coasting/gliding. This isn't really P&G, though it is close.

I've found this out in the past few months. I thought I was doing okay by not tailgating and not stopping hard, but thinking ahead further than just the immediate area is starting to pay off. I'm looking at two or three stop lights ahead now and trying not stop (except at stop signs, I don't roll through). I may be going 10 mph when the light turns green, but that's better than getting the car up to speed from a dead stop. I drive like this coming home from work around eight in the evening, so traffic isn't a concern.
For me, watching the numbers and graphs was too much, I get better mileage when I'm not trying too hard. I keep an eye on things, but I'm not a slave to them.

[Codyroo]

Originally Posted by Danny Hamilton

That's an increase of 00:26:47.123 per trip or 9 days 16 hrs. 8 min. 35 sec. per year

On a purely short term personal financial cost/benefit analysis, it wouldn't likely be worth it. On the other hand, if you enjoy the challenge or feel strongly about the environmental benefits, it could tip the scale.

Danny,

One thing to consider is what you would do with the extra 27 minutes per trip. If it is an excuse to drool in front of a TV set, then I'd disagree.

[Ichiro]

I've found that slowing down on my commutes has the benefit of lowering my stress level. I spend about 10 extra minutes per day driving at a lower speed, but I'm far less wound-up or aggravated by the time I reach my destination.

[LOVL1TE]

I've had my 2008 for a month now, and love it for sure. My commute is 5 miles each way with speed limits varying from 25-35mph and I get a solid 49mpg. (It's very flat here). I drove 1.5 hours in mixed 45-55mph with stoplights and the car loaded with PA equipment and got 57mpg. The p&g with added inertia appears to have made a big difference with regeneration and the subsequent mileage. I’ll be working on my technique – especially when I get a chance to find an open road.

[darelldd]

Originally Posted by a priori

True, true. (And . . . You're writing that just because hobbit and darrell haven't yet read this thread! )

I've been paged?!

[darelldd]

Originally Posted by Danny Hamilton

Adding miles to a trip to increase MPG may or may not be eco-friendly. It depends on how many miles are added, and how much MPG is improved.

Quite true... however, I know from reading some of these threads that there are people who go out and drive the car extra for NO OTHER REASON than to increase that mileage number. The amount of gasoline burned is of no consequence in these cases - only that wonderful MPG number. It is enough to make me say bad words, so I'm gonna go ride my bike and think happy thoughts.

[a priori]

Originally Posted by darelldd

I've been paged?!

Yes, with an extra "r"! (Sorry!)

[darelldd]

Originally Posted by a priori

Yes, with an extra "r"! (Sorry!)

No worries, I've been called far worse.