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-   -   To draft or slow down? (https://www.fuelly.com/forums/f33/to-draft-or-slow-down-8225.html)

GasSavers_RoadWarrior 05-07-2008 11:21 AM

Quote:

Originally Posted by theholycow (Post 98480)
This was just posted to golfmkv.com by another user:


So, too close meant less effective draft for him.

That's interesting, it always felt to me that there was more of a pressure wave further back that you could actually feel dragging you along.

1993CivicVX 05-07-2008 11:35 AM

Quote:

Originally Posted by diver1972 (Post 98443)
I still don't understand this. There are more than a few other vehicles on most any highway that don't regularly travel at least 65mph (e.g. RVs, some light trucks/vans pulling U-Haul or other cargo trailers). The "big rig" is presumably changing lanes to pass (i.e. go around) them, so why shouldn't he do this for you? Does the "big rig" driver get annoyed at them for driving at less than 65mph and not performing a right-to-left lane change to get out of his way? No? Then why should he be annoyed at a passenger car for the same behavior?

Those vehicles have an immediately clear reason why they are going slow. A truck sees a Uhaul trailer and an RV and his neural networks have a precedanet for such vehicles going slow, so he's not going to be startled by their reduced speed (just as he's not startled when he comes up on another big rig going 40mph up a hill on the highway) but most cars he sees are wizzing by, with the slowest of them (like I said) usually not going slower than 65. This argument aside, just the fact that they have a clear and obvious reason for going slow means the trucker has no right to get annoyed. We all get impatient when drivers are not meeting the status quo--when someone takes too long to make a right hand turn (just make the turn already!) or goes too slow down the highway. We have more patience when the reason for their behavior is immediately apparent to our senses--only fellow gassavers can guess someone is going 20mph below the speed limit because they're trying to save gas, not because they're trying to be a nuesance or aren't fit for driving on the highway because they're afraid of going faster than 55 or whatever the reason the trucker would have to guess at for the unusual driving pattern of the motorist.

Quote:

Originally Posted by diver1972 (Post 98443)
I certainly understand being courteous (in fact, I feel that I'm quite courteous on most days, but not to the point where I'm a doormat); however, this line of reasoning surrounding changing lanes to simply enable a "big rig" to not have to change lanes just doesn't make sense to me.

If the "big rig" is so heavily ladened and/or the "big rig" driver is so exhausted that a simple lane change is too much of an inconvenience, then I maintain that the "big rig" is traveling too fast based on those assumed conditions. It should slow down to add a margin of safety. That's one of the responsibilities of a "big rig" driver.

Or the big rig should take a break. Exercising this courtesy is in no way being a doormat for the big rig. It's merely a way of showing the big rig extra courtesy since he is a bigger, and thus more significant vehicle demanding more respect. Obviously the big rig can make the maneuver. But so can the motorist driving slower than he should. And it's easier for the car to change lanes than the truck. I think that might be the crux of the argument. It's easier for Monroe to change lanes, and Monroe is the one at "fault" for driving unreasonably slow. But even if you can't see it, surely there must be something to our argument if Monroe and I both feel exactly same way about it? Another thing to remember, originally we were not saying one *should* move over to the left in this situation--just that there is justification for doing so.

1993CivicVX 05-07-2008 11:47 AM

Quote:

Originally Posted by PaleMelanesian (Post 98463)
In Texas, most country highways (2-lane) have paved shoulders wide enough to be another lane. It's common, even expected, for slower traffic to pull over on the shoulder to let others pass. It's even written in the driver's handbook as a recommendation. I make use of this ALL the time.

And I thought that this was only the norm in New Zealand or other parts of the world, I didn't realize this was the case in places in the U.S.! I feel like the driving laws in the southwest are less rigid.

monroe74 05-07-2008 12:17 PM

"surely there must be something to our argument if Monroe and I both feel exactly same way about it"

Not necessarily. It could just mean that we're both doormats! jk.

usxpop 05-07-2008 02:27 PM

Draft or slow down
 
OK, I've read all the posts so far on this subject and must say I'm pleased that, so far, there's no flaming of anyone by anyone else.

Much discussion about moving over to let big rigs get by in right lane. No one seems to be a big rig driver and many are expressing opinions of what those drivers think.

I'm retired now, but I drove big rigs for two different OTR (over the road) companies. Among the many things drivers think about 4-wheelers (anyone driving a car of pickup) is that almost all of them are idiots and should not be allowed to driver on the hwys. That seems harsh, but you'd have to see the many stupid things cars and pickups do in front of, beside, and behind big rigs. If you travel the hwys with a CB radio, listen sometime to comments from one driver to another about car and pickup drivers who just nearly caused big problems. Happens all the time. Oh, BTW, if you do listen be prepared for the bad language. Sorry folks, truckers can be potty mouths.

Anyway, to the subject of lane changing, driving slow, etc. What drivers want from cars and trucks is consistnacy. If you are in a lane and a big rig is coming up on you, stay in the lane until the big rig is well in front of you and safely back in the lane in front of you. I know many of you want to use P&G and lesser speeds on the hwys. If you do, pick and choose where and when - hopefully not close to big rigs. Save it for more open areas.

As to drafting. Ever see the little plackard on the back of many trucks that reads, "If you can't see my mirrors, I can't see you." It doesn't take driving too close to get into that area behind a big rig to be invisible. If you want to draft, do so at least several vehicle lenghts back. Contrary to popular belief, big rigs can stop fast enough to sucker you right under the run-under bar on the back of the rig if you're drafting too close. If you are passing a slower rig, "get'er done." Drivers don't like a car or pickup taking too long getting around. We may not be as "fleet-o-foot" as a car or pickup, but when we need to maneuver, we can make a lane change or stop quickly.

I'm still lerning about the hypermilage tricks, but don't try using them full time. There is a time and place. Which would you rather have, 70mpg by going slower than all traffic including big rigs, or get your butt run over by someone not payinng attention and hitting you from behind? Most rig drivers hate to drive through Ohio because of the speed differential between big rigs and other vehicles. 55mph for rigs and 65-70 for others. Be willing to scarifice high mpg for safety. After all the ultimate way to save gas is to not drive. However, don't die just to boost milage.

If you drive in high traffic areas (much of the eat coast corridors) just live with less milage for increased safety. The big rig driver will appreciate your safe driving. Best way to be safe around big rigs is consistancy.

theholycow 05-07-2008 02:37 PM

Quote:

Originally Posted by usxpop (Post 98583)
As to drafting. Ever see the little plackard on the back of many trucks that reads, "If you can't see my mirrors, I can't see you." It doesn't take driving too close to get into that area behind a big rig to be invisible. If you want to draft, do so at least several vehicle lenghts back.

Agreed. Reports I've read (mainly in this thread) show that staying that far back is as good or better for MPG than getting discourteously close, anyway.

1993CivicVX 05-07-2008 06:23 PM

I've gotten big rigs upset on a numerous occasions from drafting and inconsistent driving in order to save fuel. For the drafting offenses, I was probably too close. One big rig used white lights at the back of the trailer to signal to me to back off. Another did a pretty heavy break-check that had the desired effect. Since then I don't draft, or if I do, I remain several car lengths.

@usxpop: Does drafting behind big rigs pull on them at all or does it have no effect on their fuel economy? Someone was telling me that drafting crates more drag on the trucks.

1cheap1 05-07-2008 06:49 PM

The speed here in California is the same as Ohio. Its just the Big rigs go 70 to 75. The only ones that go 55 all the time are the grocery chain trucks.

Snax 05-07-2008 07:11 PM

usxpop nailed the biggest issue though: Consistancy (and predictability).

I've done multiple cross country trips where it seemed like just me on the road with a load of truckers. Listening to them talk on the CB made it clear that they mostly just wanted to know what my next move was.

Of course, one guy blurted out: "Look out for that guy in the yellow sports car! He's probably doing well over 100!" I politely responded by thanking him for alerting every cop in the listening area. But I didn't blame him for doing it. (I was doing about 110 mph at the time.)

theholycow 05-08-2008 04:46 AM

Quote:

Originally Posted by 1993CivicVX (Post 98613)
Does drafting behind big rigs pull on them at all or does it have no effect on their fuel economy? Someone was telling me that drafting crates more drag on the trucks.

In group bicycling and auto racing, drafting helps both the puller and the drafter. I can't say for sure it works that way with hypermilers drafting trucks, but I don't know why it wouldn't.

I think people assume that it would create more drag on the truck because it's benefiting the car, and TANSTAAFL...but in this case, here's my guess as to how it helps the truck: Normally, the truck has to burn fuel to pull that vacuum behind it. The car fills part of the vacuum, and aerodynamically becomes part of the truck and is a sloping the rear piece instead of the truck being cut off flat. I'm no aerodynamics expert, so this is all conjecture.


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