Drafting a Transport Truck ... Am I Doing It Right?
 

http://ecomodder.com/forum/attachmen...1&d=1505429190

Am I too close?

Swerve now! Lol.

Depends on your speed. I feel 2 ways about drafting trucks. Either be 2 seconds or more behind so you can react to obstacles in the road, or be very close to the truck and accept that you probably won't avoid most debris in the road. I almost never follow close, and most would argue not to do it, and for some reason truckers get upset when they can't see you.

If you cannot see his mirror(s), he cannot see you.

Sometimes at night I'll follow closer just so my headlights aren't in his mirrors.

I don't draft because I don't want the stone chips.

I find reverse not all that good for fuel consumption!
I travel about 2 seconds behind trucks, sometimes a bit more, depending on the conditions. We don't seem to have a lot of debris thrown up on our roads. All trucks must have mudguards and most of the newer trucks have those anti-spray mudguards, so that helps a lot.
https://www.industrialbrushware.com....ressant_03.jpg

I try to keep a sight line ahead so I'm not surprised if the truck's gotta jam on the brakes. I also found that the benefits extend back from the truck a pretty good distance - maybe about 3 seconds?

On the flip side, as a trucker myself I don't mind someone drafting me all that much, more worried about their reaction time if I have to slow, or damage when a tire has tread separation, etc. unless it's at night when the headlights would be in my mirror, I find it a courtesy when my follower sticks to the side of the lane so I can see the car instead of just the shadow.

I found that too. And the bigger and faster the truck the further back you still feel the benefit.

Yup. The one time I logged 50mpg was chasing a truck about 5-7mph above my normal speed, right about at the back of the drafting envelope for a good long while. I can't remember the exact distance, but it was further backthan I'd have thought before.

Best I found was behind a low-loader with a huge, wide, bulldozer on the back, doing 65 mph. He really pulled me along.
The big, interurban coaches Stagecoach run here also give a good tow. You have to do 70 mph to keep up with them. Uphill and down dale.

http://www.stevenknightmedia.com/upl...ach_1_orig.jpg

Busses over here drive like lunatics, its hard to follow them.

https://goo.gl/images/y4NTbQ

https://goo.gl/images/y4NTbQ

https://goo.gl/images/YXqB7x

https://goo.gl/images/YXqB7x

https://goo.gl/images/9DLY3C

https://goo.gl/images/9DLY3C

Not uncommon sights.

My brother told me about a coach trip he made into Marmaris from the airport. Said it was the scariest bus journey he has ever made.

That's a good point, especially while riding a motorcycle. But anyway, I don't feel so comfortable drafting trucks mostly due to the visibility. Let's say I'm not a big fan of surprises :D

And another thing to consider, those diesel trucks are not always up to spec, I have seen some spew out black smoke for miles. Would not want to breathe that.

https://www.bellperformance.com/blog...moke-explained

That sounds like they are not being maintained properly.

You don't need to use the internet to know they are not being properly maintained. Possibly not even maintained at all.

If I were driving in a car with the air-conditioner turned on and recirculating instead of drawing fresh air from the outside, that would be not so likely to bother. OTOH that soot may eventually clog the cabin air filter anyway...

"Fresh air from the outside". :)

:D
Oh, come on, you know what I meant (or at least tried to mean :p)

:thumbup:

The air con on my Volvo only worked when drawing air from outside. If you pressed the recirc button the air con was interlocked out.

I once drove a '97 Volvo S40 with the 1.8L engine, and its air-conditioner did worked normally with the recirculation engaged.

I have a Class A CDL and I drive the big rigs 5 to 6 days a week. I have been doing it over ten years. I had a line driver I work with tell me a scary story. He said he seen a car follow a truck for thirty miles on a hot day and one of the rear tires blew on the rear of the trailer the semi was pulling. The tire decapitated the driver of the car following the truck. This story shocked me because I am a driver and it is a true story from someone I personally know who has been driving over 25 years.

My wife was driving with me in the passengers seat of our car one day and she was driving by the side on a big rig for awhile. I asked her to get away from the truck and she said "You are a driver". I said, "Yes I am and that is why I am asking you to get away from the truck".

Not all Class A CDL driver are good drivers. Some of these drivers weave out of their lane, tailgate cars like nobody business while hauling 80,000 LBS and pull triple trailers with the heaviest trailer on the rear of a set which causes it to weave like a snake while going down the road.

Many trucking companies do not maintain their trucks very well and they are running OLD equipment with BAD TIRES on the truck or trailer. Everyone has seen truck tires that blew all over the roadway. It happens. My neighbor was passing a truck two summers ago while a truck tire blew and it dented their car. They got lucky that's all that happened.

I stay away from the big rigs. I do not pass a semi in the lane right next to them. I do not follow them either. You do not know what can fall off of these trucks and hit your car. I stay away from the big rigs in my personal car.

If you were to ask me how to draft a truck with some degree of safety I would say do not pick a truck hauling a long box trailer with the tires adjusted all the way to the rear of the trailer. Find one where the tires are adjusted 25% forward of the rear. Long box trailers can have the tires adjusted forward or all the way to the rear so they can pass over weight scales and be legal. Following a big bus would be even safer because of the way the rear tires are mounted on the bus.

I never heard of something that extreme, but I wouldn't be willing to try it...


I'm well aware that some commercial drivers are not any good. Search for "quebra de asa" on YouTube and you'll see what some irresponsible truck drivers do in my country.


I have already seen many pieces of tread that detached from tyres. Even when they're laying on the road for a while, it may still be dangerous.


The fenders are also usually bigger on buses, so it may retain the tread of a damaged tyre more effectively.

I'd imagine the likelihood of a bus shedding a tread is much lower as if that happens with passengers on board it wouldn't be good for the reputation of the bus company.

If you're NOT ending up with the trailer as a hood ornament at each stop sign, you're doing something right.

I once had one of the duellies blow on my bus. I did not have passengers and it was anticlimactic. I once clipped a curb in a parking lot with passengers and they demanded to know if I was trying to kill them.

I have driven passenger busses also. The bus company I worked for ran older buses, but the tires on the busses had very nice tires in great condition on all of the busses. My experience is bus companies transporting people are far more concerned with tire quality that your typical business running semi trucks are.

Yes I would say the percentages of busses having tires completely blow up and rip apart are far less than the semi tucks mostly due to the busses not running worn out tires in the first place. A good percentage of tires on semi trucks are not in the condition I would want to be driving on.

I delivered a load of new tires this summer to a gas station that also services trucks broken down on the highway. The guy who received the tires said you would be suprised how bad the tires are on some trucks.

Of course. Setting lawsuits after an accident with passengers is far more complicated than dealing with insurance for cargo.

Drafting is for the stupid. Have a look in the mirror if you draft. Thats the face of supremely stupid.

Most states in the US have strict requirements on bus tires that freight doesn't have.

Thats when you shake the leg of a sleeping passanger wille hitting the brakes and screaming..... LOL
I have found that drafting influences start about 1300' (1/4mi) to 2/3mi behind the large rig(RV , semi, bus) edpendent on how dirty the aero is on the lead rig. I showed Aerohead some videosof trucks,cars, and pickups w/ w/o trailers , that diminstrated how far back the draft works .
With my 1/3 -1/4 mile interval I find that I get sucked into the pack, when a truck travling at a slightly faster than the leader replaces me as rear gard.

I haven’t tested for it, but it sounds interesting.

I’ve found that NOT passing (no lane changes; thus no related accel/decel events plus steering corrections) pays best.

On a known road (all conditions; familiarity) it is choice of a cruise control set speed just far enough below truck traffic that on a 700-mile day I may not pass more than one or two other vehicles. This is at about 62-mph. In the Kenworth.

When in the Dodge, whether or not I’m pulling the 35’ travel trailer, 59-mph is best “fast” speed for economy.

58-62/mph pretty well covers FE, and staying out of traffic. About all I need to do to get a 65-mph governed truck around me is to cancel cruise once he’s in the passing lane. Drop back off to about 52. That gets him well out ahead of me in short order.

Manage the problems first by avoidance, second by shortening those remaining.

It also allows no real penalty with the assertive almost aggressive programming of my cruise control. I’m still far below the maximum weight expected for that pickup.

IOW, a set speed 2-mph slower means I don’t have to cancel cruise as I would at a higher set speed to offset that assertiveness. That extra fuel. More work for no real gain.

As before, if one isn’t using average mph as a tool for trip analysis, you haven’t understood what I just wrote.

Use it

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On my familiar routes trucks normally do a round 80 so the ones that are poking around at my speed they're in it for fuel economy and they follow my footsteps because they see what I do Works in their trucks as well.
My favorite to draft is one that has a power to weight ratio that matches the volume a fuel I am willing to spend. Due to Combat PTSD I find it hard to close the gap smaller than the 300M Convoy interval my Battalion used in Baghdad. Gets me too worked up trying to follow at 3 second intervals

I also don't like following trucks. Yesterday while driving in a highway I had to pass a truck that was pulling 2 large trailers, and it was raining. Even passing that was a PITA.

In SUV or pickup you will see very little benefit unless they got a trailer tail

If you really really Want to do this look out for the ones that have Trailer tails those will give you by far the best benefit while a comfortable 25-30 feet away..
MPG yield is significantly higher then non trailer tail 18wheelers

25-30’?

What is your total stopping distance at that speed? Then add distance for reaction time. It’s ALWAYS going to be above 200’ which is still too close.

You need to be able to see BOTH side mirrors on the truck. AND have some idea of what’s ahead of him.

300-350’ feet back is where I start a pass. Closer than this means I BECOME DEPENDENT on his ability in driving, AND cannot see around him in any meaningful fashion.

Stupid is as stupid does. Quit this.

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This is LA tailgating is the name of the game... if you leave more then 15 feet you can bet someone will cut you off.. and possibly even forced to rear end them .


. A car length is not a standardized unit of measure.

I use cruse control it has Manual controls so I can deduct speed or add speed using the wheel controls..... without pressing the brake or canceling it out

I'm used to dealing with heavy traffic you are not..

You don't know me! You don't know how much traffic I fight every day!

I go through more traffic of every kind in a month or so than you do in a year. And in the vehicle you believe it a good idea to tailgate.

I was used to heavy traffic probably before you were born. Every major metro of this country.

You “may” survive a variety of accidents with other personal vehicles. A high percentage. You “won’t” survive most of the types of accidents created by or around big trucks (is how you should look at it).

Your bad idea of tailgating only needs one example: the tractor to trailer electrical can have a partial failure. No trailer lights. And disc brakes are increasingly common on big trucks. Pair that to awesome sophistication in the computer control of the drivetrain for maximum braking effect. These rigs can slow at a far faster rate than you understand. AND THEY WILL NOT ABSORB ANY OF THE IMPACT OF YOUR VEHICLE. You’ll be hitting a wall at above 30-mph (speed variance).

“Economy” is longest life at lowest cost with greatest reliability.

Tail-gating doesn’t feature. Ever.

The closest you want to come to the rear of a big truck is BEFORE you cannot see both of his side mirrors. No exceptions to speed or traffic. It’s also where you back away.

Tire loss is common. And 100-lb tires disintegrating at speed throw chunks that will come right thru your windshield. No time to react.

Risk Prevention should be your first rule in driving. A commute is just a commute. You chose well or badly in job or home since you haven’t an alternate to driving, now the vehicle bears the cost. Stunt driving isn’t an offset to bad choices

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if you claim I need to keep 200 feet I might as well be stopped on the freeway as other drivers will be cutting your ass off 200 feet is laughable...


it takes a full loaded 18wheeler 450 feet to stop at 65 mph
most smaller ones will stop with in 120-140 feet at 65 mph

and if their brakes go out which I have seen happen THEY can't even stop at all I have seen a 18wheeler lose it brakes on the I-15 north bound to las Vegas



you bet that driver only cared about him self and the load other wise he would have ditched the rig off into the open desert...
smoking up a storm as they are going 80 mph on the shoulder

Stupid is as stupid does.

I was leaving an entrance ramp onto IH10E from El Paso last week. A trailer tire exploded. For a change I didn’t have someone like you tailgating so close I couldn’t see them, waiting till they had room to go around me in the passing lane (I’m usually at 40-45/mph at the end of a downhill ramp when heavily-laden).

Given the tire location and debris trajectory, it could have been life-ending. The EXACT wrong place to be given tire shrapnel.

The causes of tire failure are many. Reduced, even greatly reduced under guidelines. But still unpredictable as to where and when in the main.

Tires are only one of many things that can come loose. Past cargo, an entire PAIR wheel/tire assembly might be the scariest. Or should be. They don’t stop.

Your argument in favor is hollow. Even past risk. Percent change to the annual CPM fuel cost is too low to factor.

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I just hope that he doesn't take out anyone else when he nominates himself for a Darwin award and it is not too traumatizing for those who need to clean up his mess.