P&G or Hypermilers waste gas in traffic - true?

Perhaps you might ask the same question over at CleanMPG.

I'm no fan of P&G driving but I do use "N" during warm-up or times when I'm approaching a likely stop. Otherwise, I have no commuting use for this technique compared to: (1) route planning, (2) attention to warm-up, and (3) vehicle maintenance.

During the annual hybridfest driving challenge, I've long felt the best approach would be to rent a track and have the contestants 'do laps.' This would equalize the route and allow extreme driving techniques while keeps the contestants away from non-contest traffic.

Bob Wilson

 

In heavy stop and go traffic you can't help but pulse and glide in a prius. It just happens unless you like to ride people's nice person. Other than the situation described above, I don't know anyone who would use p&g in high traffic situations. I think you are making an issue where there is none. I live in a region with a very high density of hybrids and I've never witnessed the situation you described.

 

Forcing the guy behind you to glide and coast into a red light is fun... saves gas too...

Giora.

 

+1 to Tideland's reply.

Some days on my commute to work there's more traffic than others. I know the route so well I can easily modify my P&G so its less pronounced and I stay with the flow of traffic. I often get better mpg on those days since my overall speed is lower. I actually had fun one day following another Prius. He seemed to have the same P&G pattern as I did.

The theoretical driver the OP describes would aggravate me too. I've seen that type of bad behavior before, but it was a Buick not a Prius on the road and I don't think hypermiling came into the equation.

 

P&G, hypermiling, whatever you call it -- If you pay close attention to your MFD and how you're driving, your mileage will be significantly better.

My point is, in any traffic scenario, if you want mileage badly, you can get it.

 

Sorry, it is more specific to the 2001-03, 1.5L Prius that does not have the advanced warm-up logic of the 2010-current, 1.8L Prius. Our 1.8L Prius works best if we just drive it but there are occasions when approaching a light or stop sign where coasting in "N" is more efficient.

Bob Wilson

 

I see what you mean. But you can't do anything about the things you can't control. So if you drive the best you can, I'd say that's good enough.

 

I waste gas by driving slightly faster than the posted limit on most surface streets. It isn't so much the fuel that I could be saving by driving more slowly, but it is the huge amount of fuel wasted by the neanderthals who must pass me in their lifted 4 door single passenger pickup trucks, apparently because they cannot bear to have a Prius beat them to the next red light. :madgrin:

 

Hi jhinsc,

I wont address your suggestion that other drivers cannot learn.

There is a professional report that show pulse and glide saves gas (Argonne National Lab and Virginia Tech). This report indicates an even a greater savings in a Otto engine car than in an Atkison (as the Prius is) engine car. And of course, this is how Wayne Gerdes gets 50 mpg out of a stock Honda Accord.

So if traditional cars behind a P and G Prius are pulsing and gliding, they save lots of gas, and if these same cars then come throught the light while its green, they save even more.

 

Hi Jhinsc,

Do a check of your average trip speed, and peak speed during the trip. If your timing lights, these two get closer together, and that saves gas.

How does it screw everybody else up when you come into a light just after it goes green, and the cars stopped there just have enough time to get going before you reach them? That is what you should be aiming to do.

What is screwing everybody up is red light racing, where peopel have to do the speed limit, or greater, to get to a light that day after day they know they are going to get caught at, and slow down the traffic that comes along when it turns green.

I had an interesting thing happen to me. I go slow down this long hill. I had an impatient lady in a Cadillac behind me. But, when we got to the wider section of the road, around me she goes, and blocks the right turn lane. I horn her, and she moves enough to get out of the way, so I can proceed. Her face was beat read with shame at that point. My timing was perfect so that I could make the right turn just as the left turn arrows come on. And I can get ahead of the oncomming left turners, after a stop at the light. She knew she was doing the very thing that she thought I was doing. And you think hypermilers do.

A stopped car in front of you, is worse for orderly progression along the road than anything else. The goal with hypermiling is to never stop - Wayne calls this DWB (Driving Without Brakes). Even if that means going slowly to time into a light. Its one of the wierd things about my pulse and glide route. I actually get the best mileage from it, when the average speed is the fastest, which means I timed many of the lights.

Another approach to this is what I like to call driving in the anti-traffic. With everybody having much greater peak speeds than average speeds, there are vast amounts of sparsely populated asphalt. The trick is to time into the cycle when these roads are empty. That right turn is such a situation. As there are few oncomming left turners, I can Pulse and Glide to the next light on an empty road 3/4s of a mile long. Then just as I get to a light going from red to green, the cars from the next green back at where I made the right turn reach me. And off we go accelerating again in the PandG. Of course we are have to wait for the left turning rabbits go speed up and get out of the way.