Can hypermiling techniques burn more fuel?
 

One day, I was heading to Little Rock to see a concert, and I came up behind a lady on a moped. Speed limit on the road was 55 but she was doing 30. I had to hit my brakes (didn't see her until I crested a hill) then drive up a hill in 3rd instead of being able to go up it in 4th with a locked TC as i usually do. When I had opprotunity to pass, I did so, then started to ponder something.

If you're on a 2 lane road, and people cannot pass you without slowing down first, will you cause more fuel to be burnt by other drivers due to your actions than you are saving by going slowly? The lady on the moped was likely getting 100+mpg. So she was saving fuel. But I had to spend fuel in the form of lost momentum (had to hit the brakes) not being able to climb a hill in high gear, then using a bit more than usual in order to pass her. If I was the only person to pass her, it may not have mattered much. But how many other people passed her? And how much extra fuel did they burn in the process of moped lady saving fuel?

In the instance you described, I think that the woman on the moped was definately causing other drivers to burn more fuel by slowing and then accelerating rapidly. However, I don't think that hypermiling techniques performed on a mostly open stretch of road would cause other drivers to burn more fuel, provided that they have space to pass the hypermiling driver.
For instance, if I am driving on a road with no room to pass, I will drive at the speed limit to avoid stressing out other drivers. However, on the highway with few people around, I will work in some hypermiling techniques (P+G, etc) while driving in the right lane, so people have the option of passing me.
I do think that in some instances, hypermiling techniques can actually help save fuel for other drivers. For example, in heavy stop-and-go traffic, I try to maintain a 10 second following distance from the cars in front of me. This way, when people are alternating between 25 mph and a dead stop, I can maintain a constant 20 mph, thus smoothing out following traffic. By the time I close to a 5 second following distance, 9 times out of 10 the traffic will be moving by at least 20 mph again.

I search out routes with more than 2 lanes. If there is another lane available for passing, I drive how I want and they can go around.

When i can't do that, I'll go up to the speed limit out of courtesy for traffic.
I will not exceed the limit even if they want me to.

A little tip for climbing hills in situations like that - in most cars with a 4 speed auto that only locks the TC in 4th, most will lock up in 3rd at a somewhat lower speed if you turn OD off.

ShadeTreeMech -

In one-lane-only situations I will stay around the speed limit if someone is behind me. I wouldn't fault someone for going below the speed limit on a moped. That might be her only transportation. If she was on a motorcycle that is designed to travel at highway speeds, that's different.

That said, if I were her, I would be watching my side view mirrors and "cheating right" in anticipation of someone coming up behind and passing me.

Also, from a "drive the road ahead" POV, I think you have to anticipate an accident or a slow driving wide-load beyond the crest of almost every hill, so it's hard to fault her for not going 55.

Question: If you had been actively looking for slow-pokes, would you have been able to see her in advance, or was the topography (i.e. curves and forest and other visual interference) such that there was no way you could have seen her ahead of time?

CarloSW2

:confused:

does the sun hurt your eyes on a cloudy day?

does a car save fuel if the engine isn't running?

how can ya sleep while the beds are burning?

hey that came from a song..what was that song...

how do we sleep while the earth is turning...

no, you should have also been on a moped ;)

I suppose what I was trying to infer was not that I was picking on the lady on the moped; I realize they have a limited top speed. to be quite honest, there are also likely no other routes she could have taken. And it's not like I had to slam on my brakes, I saw her ahead of me about 10 seconds before I would have hit her. Its just that it got me to thinking.

When driving up to Lead Hill, I have to go down a 2 lane road for about 40 miles. Due to the constant turns and hills there are only a handful of passing zones and no 3 lane stretches. If I had a dollar everytime I got stuck behind someone going under the posted limit, I'd be well off. And despite my attempts at behaving myself, I get agitated. It happens quite a bit out here, as not everyone is accustomed to driving the speed limit around the twists and turns. Think of the Ozarks as a very large Gran Prix circuit and you'll catch my drift.

I suppose consideration for other drivers is the major concern here. If someone wants to go slow, fine, let them do it on their own time. Same with me. When I manage to behave myself, I'll drive under the limit, especially in my van. About 45-50 I can stay in top gear and cruise to town no problem. But I always keep an eye on my 6 for oncoming traffic.

BTW if you ever come to the Ozarks, if you're not going 5-10 over the limit, you'll be impeding traffic. So when I'm going 45 in a 55, I'm really going about 15 under what others on the road will likely be doing.

To comptiger5000, I think you may be right about the TC thing in third. I'll check into it. I know my tranny will stay in 4th locked down to about 38 mph before downshifting if I'm really nice to it. My Explorer I had a switch to manually lock it up once I got into 3rd, otherwise I'd have a hard time keeping it in high gear and locked while going around 40.

It is your job to look ahead (and make good decisions). If it wasn't a chick on a moped it would be some agricultural implement, or a deer, or kids on bikes, or??

I'd be surprised if you don't actually get better mpg in 3rd gear at 30 mph than in 4th gear at 55 mph. Slower is almost always better for mpg.