I decided to give a try to getting the maximum mpg I could get on a tankful of gas. My usual driving method is to drive with the flow of traffic on roads with traffic lights and stop signs and 5 - 15 mph over the posted speed limit on highways (with the flow of traffic). I average 45mpg overall. I run my tires at 39/37. I live on Long Island, NY where we usually have heavy traffic wherever you drive. I managed to get 58 mpg out of the tank used to maximize mpg. I used all the methods discussed on this forum to achieve this. I have come to the conclusion that (given traffic conditions where I live) that you would be causing a traffic hazard by driving the way you need to drive in order to get constant high mpg in your Prius (or any other car for that matter). I know I caused angst in many other drivers in my pursuit of high mpg. If you live in an area that has no traffic it would be no problem but in any metropolitan area it would be. I have a NY state trooper friend who told me that he has given tickets on the state parkways to people who do what would be called pulse and glide in the Prius for reckless driving (impeding the flow of traffic) and that the tickets have been upheld. He does this for any vehicle that speeds up and slows down constantly (he said it is usually an older driver). He stated that it causes problems when this occurs at exits and entrances. If you constantly go from 45mph to 60mph and back down to 45mph you can be ticketed. You can also be ticketed (doesn't happen often but it can) for going at the minimum mph on a busy roadway (again for impeding the flow of traffic). I'm going back to my normal driving habits that get me 45mpg (vs my old suv mpg old 10-12 mpg). I always try to be courteous to other drivers on the road, letting them get in front of me to make lane changes and such. High mpg driving techniques are not conducive to courtesy for other drivers even if they are in a hurry.
<div class='quotetop'>QUOTE(wkramer @ Jul 16 2007, 07:54 AM) [snapback]479539[/snapback]</div> Sorry to throw cold water on your cold water throwing exercise, but traffic is not like that everywhere (although not uncommon in urban areas). One thing I do to reduce the speed variance is pulse up hills, then glide down hills.
It would not surprise me that some officers will ticket drivers who vary speeds in anything like a pulse and glide manner, just the same as they will ticket drivers who exceed the speed limit or are deemed guilty of any of a number of other infractions, real or perceived. It's in the nature of any individual official and the way he/she interprets the law and elects on any given day and at any given moment to enforce it. So what? Those who pulse and glide will continue to do so - perhaps until they themselves are ticketed. Those who get aggravated at the perception they are being impeded by slower drivers (whether pulse and glide aficionados or not) will continue to tailgate and curse, and the police will continue to apply often arbitrary interpretations of the law to charge motorists with whatever they feel is most appropriate to the circumstance - such circumstance often being whether it is easier to catch the slower driver than the faster.
I agree that continuous, aggressive P&G in the midst of heavy traffic is discourteous and possibly unsafe. If I'm constantly fluctuating between 20 and 35 in a 35 MPH speed zone with traffic all around and no chance to pass, I deserve what I get, whether it's a finger or a ticket. But I suggest that some elements of P&G can be applied to any drive. Do you ever accelerate? Of course. Use a moderate, fuel efficient pulsing speed. Do you ever decelerate? Of course. Learn how to do an arrows-off glide and watch far ahead for opportunities to use it. Slowing at a more gradual rate in rush hour traffic is considerably safer than the more typical last-minute braking, in addition to the potential effect of smoothing out traffic as suggested here. As Delta Flyer suggests, watch for hills and pulse up one side and glide down the other. With the right incline, that can done with speed changes imperceptible to those following.
Never P&G on a highway at speeds above 40MPH. Wait till it's crowded and the speed drops to below, say, 35MPH or less, then lot's of gliding. Above 40MPH get a ScanGauge and keep your RPM's low as can be and get those 70 MPG as long as traffic is constantly moving. When I was at the LIPOG meeting in April I had the pleasure to hit rush hour through New York City and onto Long Island, had mostly 60-80MPG in the traffic, brought my tank up from some make-up time on the Interstate. Also find some different routes, if you don't have to take the highway for all or part of your trip it helps. Wayne
<div class='quotetop'>QUOTE(wkramer @ Jul 16 2007, 08:54 AM) [snapback]479539[/snapback]</div> Why not just go the speed limit. I'm sure you won't get a ticket for obeying the law. This should raise your MPG to at least 50 on the highway.
You are correct but I never P&G on the highway. That's just suicidal. P&G happens on lower speed roads with light traffic. Anything more than light traffic and I'll stick to "normal" driving patterns. I don't think I need to fuel the fire for more Prius hate.
<div class='quotetop'>QUOTE(Tideland Prius @ Jul 16 2007, 11:26 AM) [snapback]479591[/snapback]</div> On my way to work the parkway is almost completely empty of other cars, today I glided from 50mph to 37mph for at least a mile and a half. The speed limit is 45mph. On my way back from work the flow of traffic is less predictable so I P&G only where I can. I don't know whether the cop has a right to pull you over for that. I guess he has to follow you and catch you doing so at least twice. Without any measurement to prove your P&G you could always say that you were going with the flow or your Prius showed an error which cleared later. How can the cop argue that catching me driving from impending the flow of traffic when he isn't doing anything about people speeding is beyond me. Anyway here in the city cops have more important things to do than bust Prius owners who P&G. It's up for us to be responsible, avoid accidents and not provoke others. I do however wonder what would traffic look like if everyone drove a Prius and P&G'd...
I agree that Prius drivers shouldn't unduly slow down traffic even though I've had my share of SUVs surge past me with an attack mode on their face. My hope is that we are starting a new driving style that will catch on with the rest of the planet at least until we have better and cleaner technology. Right now most car drivers have developed terrible driving habits, including some of us. For example, I've seen several people in this thread say you should accelerate up a hill and coast down. From my experience using the MFD, that's the wrong theory. I've found you should let your car slow slightly going up the hill, then accelerate slightly down the hill. I don't do this when people are behind me, but when the coast is clear, I've found it will save a ton of gas. Very similar to the way bicycle riders ride. My thoughts are that someday each driver should be encouraged to reduce their yearly carbon outputs by choosing a good combination of the right vehicle, good driving style, short commute, efficient roadways & city layouts. We'll probably need some type of positive incentive like a tax refund based on the percentage below average output. I'd also like to see cars in the future rated not by MPG alone, but by a combined carbon input/output figure.
Well, if you are P&Ging on the highway, then yea, you should get a ticket. That's just not a smart thing to do. However, if you are P&Ging on a regular street and like 30-40 MPH, then how in the world can they give you a ticket? I'm assuming that you aren't speeding or doing any other driving violation though. They make it sound like you have to a drive ONE speed and never change it. Well, I don't P&G. It's mainly because of all the hills we have around here. If I ever get a ticket for something like that, well....... we'll see what happens.
As far as I can tell that kind of P&G doesn't work on the highway. You slow down too quickly and the engine is always spinning so the fuel economy benefits just aren't there. My preferred method is to hold steady at the speed limit and only glide when I have a hill steep enough to sustain my speed. My current tank reads 61.3mpg on the MFD and my driving is a whole lot closer to legal than 97% of the speeding nutjobs I share the road with. And yes, the right-hand lane is my friend.
wkramer is right on. I frequently make trips to the city and once you get within 45 min of it the driving culture changes dramatically. There is no way you can survive driving to maximize fuel economy. You have to be a somewhat aggressive driver. I once tried to drive safely and economicly and I found it was much more dangerous because I had to look out for everyone else that was taking advantage of my slow/unaggressive driving
<div class='quotetop'>QUOTE(wkramer @ Jul 16 2007, 08:54 AM) [snapback]479539[/snapback]</div> Effective pulse and glide technique really doesn't occur in this speed range. Your best bet would be to exploit warp stealth on the down-hill runs and just generally feather your gas pedal at these speed ranges, maintaing a relatively constant highway speed that will keep everyone happy. Effective pulse and glide occurs below 41 MPH and is applicable to more back roads. Knowing how to stealth and glide is effective in stop and go traffic.
I am fortunate in that my daily commute is 10 mi of freeway at 66 mph and 20 mi of older, parallel highway at 46 mph. With warm weather I can apply all of the good fuel economy techniques shared here on Priuschat. I was able to earn 62 mpg with my 2005 (wrecked in October 2006). The 2007 is doing good, but only has 11k mi and has not yet reached a significant break-in point (for better fuel economy). The 2007 is just now earning 50+ mpg (cumulative for all tanks). I concur, in normal highway traffic, pulse and glide is plain stupid and dangerous. You must go with the flow and not impede traffic.
