drafting on the road?

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osabros

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from what i've understood, if you're behind a car at speed you have less drag affecting you because the car in front is leaving a kind of pocket of clean air behind it, and this helps your acceleration and fuel economy.
so i'm wondering: could i use this on the road? is it possible to keep a safe distance from the car in front while enjoying the increased fuel economy that comes with drafting? to what distance is the draft effective?
 
I doubt it will have any significant/noticeable impact on fuel economy. NASCAR uses the draft as well.....but they also race bumper to bumper.

I've heard that on highways you should get behind large trucks/lorries to take advantage of the "draft" but there has yet to be any scientific reporting done.
 
osabros said:
from what i've understood, if you're behind a car at speed you have less drag affecting you because the car in front is leaving a kind of pocket of clean air behind it, and this helps your acceleration and fuel economy.
so i'm wondering: could i use this on the road? is it possible to keep a safe distance from the car in front while enjoying the increased fuel economy that comes with drafting? to what distance is the draft effective?
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The gains are too insignificant with modern cars being very aerodynamic. For it to be effective, you need to be at least a meter between each other. Or, look at this way:

-Save a bit on gas by drafting someone.
--lose a lot, possibly your life, when you hit someone in the rear because you were too close.


CHOOSE.
 
Have you seen the Mythbusters episode on drafting?
 
Mythbuster did a test on a Lorry (s05e11)
You do save alot of fuel if you are drafting a lorry.
At 100 feet they saved 11% and at 20 feet they saved 27%.
You decide if that's what you call "safe distance" :p

They travelled at 55mph and used a Dodge Magnum.
 
Karoug said:
Mythbuster did a test on a Lorry (s05e11)
You do save alot of fuel if you are drafting a lorry.
At 100 feet they saved 11% and at 20 feet they saved 27%.
You decide if that's what you call "safe distance" :p

They travelled at 55mph and used a Dodge Magnum.
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Neither. If I cannot see the trucks mirrors, I am too close.

Never been in an accident, either. Funny....
 
^They said that you should be atleast 150 feet behind the vehicle infront of you. Here in Sweden they say 3 sec.
 
In New South Wales they say you should leave a gap of 2 seconds to the car in front (or that's what the recommendation was when I was getting my license). And you can be fined for travelling too close to the car in front, so while you might save a little in petrol, you run the risk of losing more in fines.
 
You can definitely benefit from it, its just tedius and i hate it unless i'm in a really mild mood. People have a tendency to underestimate the how small things can effect aerodynamics at speed.

I remember reading about how the original elise had to be redesigned with a small spoiler on the back because the original (flat) back end created too much lift.

(note the diminutive size of the spoiler)
Elise_50anni.jpg
 
I knew a guy who'd draft behind his friend's trailer. It helped a lot for obvious reasons, but was dangerous as fuck.

Simply put -- yes it helps, but usually isn't worth it.
 
Karoug said:
Mythbuster did a test on a Lorry (s05e11)
You do save alot of fuel if you are drafting a lorry.
At 100 feet they saved 11% and at 20 feet they saved 27%.
You decide if that's what you call "safe distance" :p

They travelled at 55mph and used a Dodge Magnum.
Click to expand...
Wow, I had no idea it would be that effective! I'm not about to go tailgating semis (I can out-brake one if necessary, I'm sure :p ), but I will keep that in mind the next time I'm on the interstate.
 
in israel we're told to keep 2 seconds distance, which at motorway speed 100 km\h means the recommended distance is ~54 meters (=164 feet). so it seems to me like drafting is a bit too dangerous in normal circumstances behind a car, but i think i will give it a try occasionally when behind a lorry.
thanks for the answers guys 8)
 
I'd much rather keep a safe distance than save a little bit of fuel and 1. Be fined for tailgating or 2. Smashing right into the back of the car in front of me.
 
I know on the track if you want to slip stream another car you need to be fairly close. Don't know about the distance since I'm busy thinking of other things. Following trucks has the issue of a delmainating tyre hitting you, all the rocks and junk that fall off of them screwing up your body/paint work and not being able to see around them to know if they are going to run over any rubbish. As for the police getting someone for tailgating, I'm yet to see or hear of that one in Brisbane...
 
tigger said:
Wow, I had no idea it would be that effective! I'm not about to go tailgating semis (I can out-brake one if necessary, I'm sure :p ), but I will keep that in mind the next time I'm on the interstate.
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No. No, no, no.

You cannot see past the lorry. Forget the fact that he can't see you for a minute. You cannot see what's going on on the road ahead of him. If you draft behind him, even if you can out-brake him, your reaction time along with the speeds you're travelling means you wouldn't even stand a chance. You'd still be a flat pancake attached to his rear lights.

And in a fight, your car would definitely come out worse.

Sorry, drafting on the roads is stupid. Simple as. Yes, it may save you a few pennies, but to even consider it as being safe on the public roads is absurd. He (the lorry driver) will not know what you're doing, other cars around won't know what you're doing.

And even though you can see what's going on on the road in front of cars in front of you, it's still no excuse to do it.

Don't. Please.
 
Just like when these morons in sports cars ride the bumper in my truck.. Tailgating will get you flatter than a pancake when I hit the brakes.
 
I remember on long car trips my dad would find a Semi that was trucking along at 70-75mph and spend a few minutes getting the cruise control set to the same speed as the truck's.

Saved a ton on fuel.
 
I hate drafting trucks - they kick up so much DIRT and gravel. Hearing little pellets bounce off my car, worrying about pock marks in my clear coat and windshield are enough to drive me INSANE.

I've seen drafting a lot more in Europe than in North America. I've seen it in Italy and France where gas costs a BUTTLOAD.

I think with the lacklustre training most drivers have in North America, drafting isn't even possible. You'd have to get these people to put down the blackberry, learn to modulate the throttle and brakes and not rely constantly on Stability Control and ABS, figure out how to counter-steer during a fish-tail, and so on and so forth before you even consider an advanced driving technique like drafting.
 
Semi trailers draft each other and it is really an incredible sight to see two road trains blasting along the highway doing about 120kph separated by less than half a cars length.
 
Red_Bull said:
Semi trailers draft each other and it is really an incredible sight to see two road trains blasting along the highway doing about 120kph separated by less than half a cars length.
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it's funny until the one behind thinks he can overtake. when he pulls out the huge truck gets hit by the wind and looses all its speed. knock the whole think back a good distance before he can get the speed up again.
 
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