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A definition of what "Drafting" is would help. I consider myself to be drafting when I am 2 seconds back from a truck and at that distance I gain as much as 10mpg. BUT according to the insurance companies, that is a safe distance and they would not call it drafting. BUT technically it IS drafting as it reduces your wind resistance. I have found that even 3 seconds back is a really good for mileage if it is an irregular load, like a big Caterpillar on a flatbed.

Jim,

For your benefit I will summarize.

It was not only politics in 2008 that got smeared, although interestingly tire gages were thrown in. ;) The way drafting was publicized was the extreme version that VWs did as early as the 1960's behind semis...Mythbusters did an episode on it in 2007. As far as the general public is concerned - drafting is tailgating within a car length of a large vehicle such as a 18-wheeler.

Nearly two years ago, the first hypermiling article came out. As gas reached $4.00 a gallon, hypermiling articles were common - it became Word of the Year. Unfortunately, much of the media distorted what hypermiling really is. These days, so many stories in general just copy the first few articles and don't do serious research, but the lack of effort could be maddening as many articles did not even bother to contact hypermilers. Then there is the reality that a nation that 90% or so of the drivers routinely go over the speed limit is going to be biased against it. Don't know how it fit into their self-interest, but the AAA made a major press release against hypermiling....they seem to have toned it down somewhat as it's just one more issue they oppose the green position.

Im not green, just very very cheap.

I'll rephrase green position on my last post to say the AAA has had a long history of going along with Detroit (http://en.wikipedia.org/wiki/American_Automobile_Association#AAA_and_the_environment), promoting gas guzzeling and going light on safety issues....many of these issues are not exactly partisan or wedge issues.

All too often, hypermiling articles seemed to focus less on what it, but more of an alarmist OP/ED by either the uninformed or opponents...if one were to Google the articles, a clueless reader would believe the typical hypermiler recklessly tailgates semis and rolls thru every intersection he gets.

HTH

You dont have to draft semi's to get good mileage. I once drafted a Corvette at 85 mph for 50 miles getting 73mpg. I prefer to draft SUVs or pickups. The results are the same as semi's but the visibility is better.

CleanMPG does not endorse drafting anything.

You never know the guy in front of you may be distracted and suddenly throw their brakes, etc.

The media and haters have fixated on drafting so much I don't even want to give the appearance of doing it.

If you are following so close that you cant stop when the other driver hits the brakes suddenly, you are NOT DRAFTING, you are TAILGATING! There is a difference that neophytes dont understand.

The most effective draft is between 3 and 4 car lengths back...sometimes further...you have to feel for it.

When I was drafting the Corvette I was on an outing with the Corvette club and there were 30 Corvettes in the group and one Insight...right behind the lead car, three car lengths back.

This is a PR issue, therefore CleanMPG is distancing themselves from anything construed as drafting.

Two years ago when hypermiling was in the media, most articles injected drafting and rolling stops even if the reporter never mentioned it when interviewing any of us. (you can find many of them here if you search) A Channel 5 Seattle reporter interviewed Wayne then gave as much time to a Washington State trooper condemning hypermiling, even though he just heard of it, much less knew what it was.

The point is, why do something that will repulse the masses to the point of not trying anything to save more fuel?

There are not many circumstances I can benefit from drafting, anyway.

I just dont agree with that sentiment. Proper drafting is not recognizable from the roadside. AAA even suggests 3 car lengths as a following distance. Following at that distance is not even a bother to the driver in front. You are just a fellow traveler. If you want to see the effectiveness of drafting, just note how your mileage goes up when you get on a freeway that is reasonably populated. Because all that traffic has causes a general wind pattern in the direction you are traveling.

Promoting drafting is to hypermiling as Tony Hayward is to BP's image.

Most, if not all of us get unintentional drafting - I don't deny that.

The problem is detractors made it seem hypermiling amounts to drafting, rolling stops, and other such recklessness....that's NOT HYPERMILING.

The AAA had a big press release condemning hypermiling based on the misinformation - did you see our rebuttal to the AAA on our main page?

It seems obvious you have not read up on the history hypermiling coverage.

That's why we avoid the "D-word."

If you are following so close that you cant stop when the other driver hits the brakes suddenly, you are NOT DRAFTING, you are TAILGATING! There is a difference that neophytes dont understand.

The most effective draft is between 3 and 4 car lengths back...sometimes further....

Out here, 3 or 4 car lengths is still tailgating. Not that it is enforced any better than the speed limit.

Minimum legal spacing at 60 mph is 8 of my car lengths. The Two Second Rule means 12 lengths.

AAA even suggests 3 car lengths as a following distance. :eek::eek::eek:
Do you have documentation? If so, this exposes more hypocrisy on their part.

AAA even suggests 3 car lengths as a following distance.
Uh, no. Three seconds maybe, or even more (http://www.aaaexchange.com/main/Default.asp?CategoryID=3&SubCategoryID=4&ContentID=313&SearchString=following+distance), but not three car lengths.

It seems obvious you have not read up on the history hypermiling coverage.

That's why we avoid the "D-word."

You are wrong. I do know the history.

I also know that Jews died in Germany because people wanted to be politically correct. This country is going down the tubes fast because people want to be politically correct. And good mileage goes down the tubes because people want to be politically correct.

I dont chose to contribute to the fall of mankind by being politically correct.

I speak the truth not pablum. I chose a clear mind over opium. I chose to open my eyes rather than wear blinders.

There's a "throw the baby out with the bathwater" issue here. If people hear the word Drafting, they tune out the rest of what we have to say as crazy and dangerous. Better to not mention that word, and have an audience, than to say it and lose them.

So lets see...

Back in the summer of 2008 dozens of hypermiling articles appeared with a mention of "drafting semis and rolling thru stops". It was not unlike the Dust-to-Dust "survey with the later refuted assertion an H2 Hummer is greener than a Prius, or earlier this year the hysteria that made it seem millions of Toyotas will uncontrolably go full throttle. The articles are here - you refuse to read them.

On the main forum page is CleanMPG to AAA:
• Hypermiling Rebuttal • (http://www.cleanmpg.com/cmps_index.php?page=AAA)

Couple of years ago the AAA put this press statement of self-serving purposes that "hypermiling" is semi-drafting, rolling stops, impeding traffic, etc. That press statement I just linked cost myself and other members $1000....and you don't even bother to read it? :mad:

Instead of at least reading that link and making an honest effort to get up to speed on the hypermiling bashing, you chose to ignore it and inject opinion with no facts....typical when someone insists on arguing regardless if their point is correct.

What does your reference to the Holocaust have to do with hypermiling? I'd say a weak arguement (http://en.wikipedia.org/wiki/Godwin's_law).

So after all the time and money spent to keep distractors painting us as reckless idiots, you feel it's alright to pick this thread and essentially say: "They're right - hypermilers draft?"

A laudable position, however... you do need to consider that capable communication is efficient and precise transmission of your concepts to a likewise understanding in your listener. The simple fact of the matter is that "drafting" has a popular understanding (which is quite narrowly focused on something like 2" of vehicle separation and heavily influenced by Nascar anecdotes) with many negative connotations and associated "knee jerk" conclusions. While it is true that in the strictest sense of definition your words may be correct, they are not conveying your meaning.

This is why we have eschewed any mention of drafting in connection with hypermiling. The general public does not make any distinction between tailgating and drafting (and in fact I suspect most people would tell you that drafting is tailgating in the effort to save gas) and will simply "shut down" as soon as they hear that word... lapsing into preconceived notions and aggressive rejection of conversation.

Please consider this when speaking of hypermiling -- we all suffer when our intentions are misconstrued by the people we describe our activities to.

You are wrong. I do know the history.

If you have an open mind, why, WHY did you intentionally ignore our press release responding to the AAA's attack (http://www.cleanmpg.com/cmps_index.php?page=AAA) and not bother to read some of the hypermiling articles back from 2008? So far you are proving you either don't know the history or in serious denial.

I also know that Jews died in Germany because people wanted to be politically correct. The Holocaust political correct?! This discussion has nothing to do with anything the Nazis did, yet you toss this emotional rubbish known as Godwin's Law (http://en.wikipedia.org/wiki/Godwin's_law)...it's generally acknowledged an argument is lost when this is done.




This country is going down the tubes fast because people want to be politically correct. And good mileage goes down the tubes because people want to be politically correct.

I dont chose to contribute to the fall of mankind by being politically correct.

I speak the truth not pablum. I chose a clear mind over opium. I chose to open my eyes rather than wear blinders.

You can't handle the truth
Without bothering to get familiar with CleanMPG, you are TELLING us what hypermiling is. We work hard and keeping hypermiling from being demonized, yet you are insisting to promote fringe techniques to do just that.

Hi Jim:
... for 50 miles getting 73mpg.
I had ONE TANK that bad while driving an all-highway commute for an entire week in below 0 temperatures and it certainly did not have anything to do with close-in drafting.

Insight's in particular are leanburn animals and love to be between the limits at over 100 mpg. Begin the drafting game and your fuel economy plummets as you have posted here the past two days.

Leave the drafting up to 98% of the rest of the world that does it but they will deny it until their last breath. Anyone out on the Interstate can name 98 out of 100 vehicles that are pulling this stunt yet not a single hypermiler is amongst them... Look at the pic in the AAA rebuttal for an idea as to what these clueless slobs have in store… In addition, look up the write-up on the Prius w/ the Tech Package including the Radar Cruise. At its maximum it was 2-seconds with the short and intermediate positions at 1.0 and 1.5 seconds behind. Way to close and this is from the manufacturer!

You want the big numbers and high lmpg, it will not come from drafting on the highway but from driving between the limits in the far right lane while RR. Don’t believe me though, I only had the Insight for 2-years and 36,000 miles with a lifetime mpg of just 92.8 :rolleyes:

Good Luck

Wayne

...

Without bothering to get familiar with CleanMPG, you are TELLING us what hypermiling is. We work hard and keeping hypermiling from being demonized, yet you are insisting to promote fringe techniques to do just that.


Totally agree. :thumbs_up:

Time and time again, we get to fight off allegations that drafting is a sanctioned Hypermiling technique when in fact it is not.

As Wayne and other often say, there are plenty of techniques in the hypermiling toolkit that that not only enhance one's lawful compliance on the roads but also do not compromise safety at the expense of reckless driving behavior.


Cheers;

MSantos

Jim,

All the safety and political issues with drafting aside, I think you are confusing turbulence with draft. Behind almost any vehicle there will be a pocket of air that moves with the vehicle. That's the draft. Further back will be whorls of air that detached from the airflow around the vehicle, generally moving in the same direction as the vehicle, only at a lower velocity. That's turbulence.

Your statements that you think that irregularly shaped vehicles give you better results than box trailers makes me think you are relying on turbulence.

Can turbulence help mpg? Possibly, particularly in headwind conditions where it may help to bust up the headwind. The downside is that driving in turbulence forces one to move at the speed of the target vehicle, and slowing down to a more efficient speed usually nets better results.

Much as I hate to say it, Mythbusters proved that getting stupid dangerously close in the draft increases mpg more than driving further back in the turbulence. IOW, there is no "sweet spot" 2-4 seconds back. Their mpg increased until they were so close that the driver had to keep adjusting speed to avoid hitting the trailer, and that hurt mpg. They could rely on their test semi to go at an exactly steady speed; one could never get that close on the highway.

Consider also that NASCAR drivers draft as close as they can, even to the point of blocking airflow to the radiator and overheating the engine. If driving further back reduced drag more, wouldn't they have figured that out??

This is "Clean MPG", after all, so you shouldn't be surprised if people are unimpressed that you got 75mpg at 85mph. Simply slowing down would net you 20-25mpg in the Insight-I. That's roughly 30% improvement, an increase most people around here would be delighted to get.

Why make an issue of something which has been proved not to work, which is dangerous, and which closes others' minds to anything else we might say here???

AAA even suggests 3 car lengths as a following distance.

3 car lengths works out to about 45 ft. At 60 MPH that would be about a half second following distance. I don't know of anyone that actually recommends half a second of following distance. Human reaction time is an average of about .3 seconds meaning you would have .2 seconds to avoid that car to braking/swerving/run over debris.

If you are following so close that you cant stop when the other driver hits the brakes suddenly, you are NOT DRAFTING, you are TAILGATING! There is a difference that neophytes dont understand.

The most effective draft is between 3 and 4 car lengths back...sometimes further...you have to feel for it.

When I was drafting the Corvette I was on an outing with the Corvette club and there were 30 Corvettes in the group and one Insight...right behind the lead car, three car lengths back.
What is the reputation 'hypermiler' is earning? Is it a relaxed, calm, smooth driver or has it become associated with "ICE (http://www.cleanmpg.com/forums/glossary.php?do=viewglossary&term=28) vests," "turning off engines," "drafting (http://www.cleanmpg.com/forums/glossary.php?do=viewglossary&term=133) trucks," and "pushing cars in the heat on the street?"

The reputation of 'hypermiler' is enough that I prefer the term, efficient driver, since it is not burdened with the bad-boy reputation of extreme driving. Boring, old-man, efficient driver, that is me.

A bunch of Corvettes get together and you guys decide to drive at 85mph drafting each other on public roads??? You know...they say accidents are generally not planned...but please tell me I'm missing something here.

I'm sad that my favorite website now has references to Hitler and the Holocaust.

Hi Southerncannuck:

Hitler was removed... The Holocaust stuff was Jim's so I am giving him fair shake... Not deserved but fair.

Good Luck

Wayne

Hi Southerncannuck:

Hitler was removed... The Holocaust stuff was Jim's so I am giving him fair shake... Not deserved but fair.

Good Luck

Wayne

I think Godwin's law still applies though.

My take on close drafting is that it requires too much focus for me to want to do it for very long. One of my personal highway safety guidelines is that I don't look away from the vehicle I'm following for a longer period than the time gap between us. If I'm drafting closely this means that I can't adjust the radio, check a map, look at the scenery etc...

It's boring and tiring if done "safely", so I don't do it much.

What is the reputation 'hypermiler' is earning? Is it a relaxed, calm, smooth driver or has it become associated with "ICE (http://www.cleanmpg.com/forums/glossary.php?do=viewglossary&term=28) vests," "turning off engines," "drafting (http://www.cleanmpg.com/forums/glossary.php?do=viewglossary&term=133) trucks," and "pushing cars in the heat on the street?"

The reputation of 'hypermiler' is enough that I prefer the term, efficient driver, since it is not burdened with the bad-boy reputation of extreme driving. Boring, old-man, efficient driver, that is me.

Wow, a quick cut and paste of your post from a year ago. :rolleyes: Brilliant again.

I've experimented a bit with distant drafting at the 2 second mark, and except in strong headwinds haven't found it to be of any benefit. It's fatiguing to stay that close behind a truck for any long distance, and honestly it probably reduces my mileage because it prevents me from DWLing, P&Ging or otherwise traveling at optimal speeds for fuel economy.

Professional drivers are taught to observe a 4 second following distance -- beyond even any beneficial distant drafting window. And most of the time that's about what I observe.

I do not draft, nor can I advocate it. My advice to most folks who want to get better highway fuel economy is simple: AIR UP and SLOW DOWN. There are other things you can do, but those are the two big takeaways for mass consumption.

This was part of the thread/sticky: CleanMPG and Drafting, but this discourse was defeating the purpose of the sticky (i.e. drafting is an illegitimate hypermiling technique), so it's split off now.

Some speakers are referred to as demagogues because they are not appealing to reason, but emotions, self-interest, prejudice while ignoring some reasoning - not unlike the drafting advocate on this thread was doing, although demagogy is overstating it. I only point out that some speakers engage bad practices that make them undeserving of the name speaker, some professions take away licences for behaviors deemed inappropriate, and drafting is an inappropriate hypermiling technique.

Hypermiling is about saving fuel. I might go with Carl Edwards doing some hypermiling on a race track going 150, but going 85 on a public road drafting Corvettes? That's speeding on any public road in the US benefiting from guzzlers.

Unlike legit hypermiling techniques, drafting is something you can't control. It could save fuel and be safe one moment and not be the next.

As a few have noted, drafting benefits diminish as the car is more aerodynamic.

I've seen a substantial impg benefit from following a semi at two to three trailer-lengths. I'm sure it won't be perceived as tailgating, because other cars cut in to fill the gap all the time. The limiations of this technique include that it doesn't work in a crosswind, it's hard to see around a semi to maintain awareness of the traffic ahead, that a ridge will force you to choose between following the trailer and ridge riding, and that you may be tempted to go as fast as semis do. But if you find a bread truck going your speed, it may present an opportunity.

Anyway, it seems like a technique worth discussing, as long as you mention the safety considerations, and never tailgate.

Talking about safety considerations, tractor trailers take longer to come to a stop than cars. So as long as you keep a safe distance to allow for reaction time, just as with following any other vehicle, I don't see an issue.

It's all about keeping a safe distance. You could be a hundred feet behind a semi at 60 mph and you would be drafting, yet that would be completely safe for a diligent driver.

I personally feel safer a hundred feet behind a tractor trailer than 50 feet behind another car, even though most people would percieve being safer behind the car.

Regarding the association between hypermiling and "extreme" fuel economy techniques, well the problem here is the hyper prefix. Although it was meant to mean over, above or beyond in this context, the media took it as meaning excessive, denaturating the word and associating it with danger, which appeal to emotions and make good headlines. The europeans had it right with ecodriving imho.

You could be a hundred feet behind a semi at 60 mph and you would be drafting, yet that would be completely safe for a diligent driver.
This has all been discussed in the posts above. At 60mph you travel 88 feet per second, so 100 feet would be 1.13 seconds, which is unsafe. Human reaction times are around 0.3 seconds. That's just the reaction time, in a car you then have to decide on a course of action (swerve, brake, whatever), execute it, and have it take effect. Following at 2 seconds (180 feet at 60 mph) is the minimum usually given, with 4 seconds (350 feet) preferred.

When Mythbusters tested drafting they got the following results:

"Full-scale test
Freightliner lent the MythBusters one of their new Cascadia big rigs, which they are billing as the most aerodynamic big rig on the market.

Mike Ryan, Hollywood stunt driver, was there to educate Grant on the ins and outs of drafting. Also on-hand was Andrew Smith, test engineer, who helped them hook up a computer to the fuel injection system to accurately measure the fuel consumption.

55mph control: 32mpg
100ft: 35.5mpg, 11% improvement
50ft: 38.5mpg, 20%
20ft: 40.5mpg, 27%
10ft: 44.5mpg, 39%
2ft: 41mpg, 29%
The fuel economy actually dropped at 2ft. Andrew Smith's theory was that at 2ft, Grant got nervous with the throttle as it was difficult to maintain that 2ft gap."

So 180 feet back back one might expect a few percent better mpg; at 350 feet almost nothing.

As stated above, driving at 50mph without a draft and using true hypermiling techniques, will improve mpg far more than drafting at 55mph or the even higher speeds that trucks usually go. Partly because going faster burns more gas, drafting or not, and partly because drafting makes it impossible to use many of the most effective hypermiling techniques.

Robert,

I don't deny that windbreaks from drafting happen to us all simply to traffic.

Just saying we can't control other drivers or the weather.

I think your aeromod project is better because unlike traffic, you can control that.

And that 0.3 second reaction time is only valid under situations of intense concentration. Traffic engineers generally assume a minimum of 1 second reaction time under normal urban driving conditions.

On a long highway drive when it's easy to get lulled into a slightly less elevated state of attention, 2 seconds is the absolute minimum safe distance unless you happen to be high on crack.

Age also plays a role: I probably felt "comfortable" with a 1-2 second following distance when I was a young driver, but I can tell my reaction time has slowed considerably as I have aged. I don't have the lightning reflexes that I did in my 20s.

And then there's toxoplasmosis (http://www.biomedcentral.com/1471-2334/2/11&y=027AE927B95A80DA&i=487&c=9103&q=02%255ESSHPM%255BL7vq%257Cmz~lz%257B%253Fhz%257D%253Flvkz%253Fkm~yyv%257C6&e=utf-8&r=4&d=wownrm-en-us&n=EB7K5H7O4HLK2FOS&s=1&t=&m=416B25A7&x=0125F05297E2A14E). Widely prevalent in the population, this infection has recently been demonstrated to dramatically increase reaction times and is associated with a 2.5x higher rate of auto crashes, potentially responsible for as many as a million accidental deaths a year worldwide. If you have cats, you should probably leave even more room! ;)

And human reaction time is only 0.3s under situations of intense concentration.

Behind a semi, something could go wrong nearly this quick.

http://www.youtube.com/v/sWPDIp9GoEw&hl=en_US&fs=1

...unintentional fire show at a Rammstein event after pilots were too close to have any safety margin. :eek:

And then there's toxoplasmosis (http://www.biomedcentral.com/1471-2334/2/11&y=027AE927B95A80DA&i=487&c=9103&q=02%255ESSHPM%255BL7vq%257Cmz~lz%257B%253Fhz%257D%253Flvkz%253Fkm~yyv%257C6&e=utf-8&r=4&d=wownrm-en-us&n=EB7K5H7O4HLK2FOS&s=1&t=&m=416B25A7&x=0125F05297E2A14E). Widely prevalent in the population, this infection has recently been demonstrated to dramatically increase reaction times and is associated with a 2.5x higher rate of auto crashes, potentially responsible for as many as a million accidental deaths a year worldwide. If you have cats, you should probably leave even more room! ;)

Following the rabbit trail...

I do. I've got a nighttime halo around oncoming headlights, from an infection in my right eye. Could have blinded me if it was on the right piece of my retina. Also I have little floating junk that swirls around when I move my eyes. Most likely I picked it up when living overseas.

Toxoplasmosis is nothing to trifle with.

Andrew - don't know if "floaters" is necessarily toxoplasmosis caused - it's common to many older people (and me :( )

True, chuck. In my case it's clearly related - none before, then they were there immediately after the infection.

I guess I should plan around slow reaction times. I know I've never had fast reactions anyway.

If you are following so close that you cant stop when the other driver hits the brakes suddenly, you are NOT DRAFTING, you are TAILGATING! There is a difference that neophytes dont understand.This is the lastest in hundreds of articles that STATE we draft semis: Electric Cars 101: How Far Will They Go? (http://www.cleanmpg.com/forums/showthread.php?t=33396) (2nd para)

Do you know how it feels to be TOLD countless times you do or your are something you clearly are not? I'd think you would resent it.

My only question on the article linked is if it was an honest mistake, just being lazy, or a malicious lie?

This has all been discussed in the posts above. At 60mph you travel 88 feet per second, so 100 feet would be 1.13 seconds, which is unsafe. Human reaction times are around 0.3 seconds. That's just the reaction time, in a car you then have to decide on a course of action (swerve, brake, whatever), execute it, and have it take effect. Following at 2 seconds (180 feet at 60 mph) is the minimum usually given, with 4 seconds (350 feet) preferred.

Semis stop dead in their tracks off course. After that 1.13 seconds where would the semi be?

Semis stop dead in their tracks off course. After that 1.13 seconds where would the semi be?
I don't want to find out, thanks!! Personally, I'm not interested in testing whether I can outbrake a semi. Especially when I can get better mpg improvement in other ways.

Also, it isn't just a question of who can stop faster; it's also a question of avoiding road debris that you can't see because the semi trailer blocks your view. That debris isn't moving at all so you can't outbrake it.

This falls into the category of "I haven't had an accident yet so it must be OK to do."

One day I saw a guy in a car stopped in the median with a long 2x4 sticking out of his windshield. He was just sitting there staring straight ahead, from shock I guess.

As lightfood said, it's not just the truck itself that you need to be able to react quickly to.

Items falling off/out of trucks. I know someone who years ago narrowly missed hitting a two foot cube of glass that slipped off the back of a truck, and probably wouldn't have survived if she'd been only 2sec behind. Maybe less of an issue with closed semis, but flatbeds and dump trucks can throw stuff at you. I've heard of several instances of drivers being killed by rocks coming off uncovered dump trucks.
Road debris. A semi can safely drive over rocks, dimension lumber and other common road debris that you cannot drive over. Or they can throw debris at you: I once caught a 4x4' sheet of plywood that got lifted by a bus in front of me, damaging my car.
Tires. As we all know, semis often throw off "alligators" which can either hit you or obstruct your path. On mountain passes, semis' tire chains are an even greater danger than the tires themselves.
Other vehicles. As you pointed out, an 80,000 pound semi that collides with a car might maintain its momentum for quite some time. But the car it hits might come at you a lot faster.

Also remember that although YOU may be leaving an adequate following distance, the vehicle BEHIND you may not. And you have NO idea what their reaction time is. For all you know, they could be drunk, texting, reading a map, reaching to the back seat to slap their kid, digging out the last french fry from the bag, or nodding off to sleep. Leaving more room in front of you gives you the option to brake less dramatically and avoid getting clobbered from behind.

We can agree that drafting is a bad idea, but what is the effect of being drafted on MPG? Drafters seem to be very common in most areas. (Probably why AAA seems to talk so much about it!)

There is a very small MPG benefit to being drafted.

The people behind is what the yuppie button (http://techno-fandom.org/~hobbit/cars/yb/) is for.
.
Not all dropped objects off trucks are avoidable no matter how
careful you are, of course -- if they're going the *other way*,
for example. Like what happened to my windshield (http://techno-fandom.org/~hobbit/cars/wshf/) recently.
I now keep a spare one of the fix-kits in the car.
.
_H*