Drafting techniques/strategies

Drafting is also known as tailgating. It is illegal on public roads. You have to be VERY close for it to have an effect. So close that if the car in front slowed down unexpectgedly you would hit it.

 

Way too close! Especialy behind trucks(biggest vehicle, biggest draft). Don't do it! Drafting is for Bicycle racers and Race cars not street cars.

 

You have a Prius and will get great gas mileage. Why take the chance on killing yourself (and taking a couple other drivers and their passengers along with) by doing something illegal and dangerous in order to gain more mpgs?

It was greed that really killed the cat, not curiosity.

Besides, there are other, legal, ways to modify your driving style and squeeze more miles out of each gallon of gas.

You want a thrill, at speed? Learn to draft on a bicycle. Then race.

 

Driving down I5 and SR99 in the Central Valley of California I noticed a small increase as I pulled up beside large trucks. But ya got to be in the "sweet spot" and it seems the "sweet spot" moves a bit. Plus you have to be tucked in close 6 feet or less. The sweet spot seems to be about 8-15 feet back from the front of the truck or almost at the end of the truck to about 10 behind and to the side. It also depends on if it is a Cab Over or a conventional. Don't forget, that is the truckers blind spot so you stay there at your own peril. On several occasions I was able to stay in the "sweet spot" for a couple mi. due to traffic conditions. Very nervous driving and the increase is only 2-3 mpg, that I could observe on the MFD. Not really worth it considering the stress of driving in that position verus the benefits. I have been told by some guys that race that you have to be as close to the vehicle in front as it is tall. So that a sedan or SUV would be within 3-6 feet and a 18 wheeler would be 10-13 feet. I wouldn't put it past any of those guys to tap the brake just to make you lose your water or soil your pants. 8^\
In fact that's what I would probably do myself. I hope you didn't get the leather option. 8^)

Wildkow

 

Are you seriously going to try "drafting" as a means to gain mpg? Or do you and your Prius need "help" out in the passing lane? :lol: :lol: :lol:

 

If you engage in drafting in an automobile, you are tailgating and are a hazard and menace to all other vehicles around you. Please don't do it.

 

the best legal draft you will get is when you cruise with normal traffic.. it isn't much of a draft at all. In order to get a real draft you have to be between 10 and 15 feet behind the car in front of you. I used this technique when i was following my father through Ohio in his F350 Duelly with a bed shell... i was then getting around 85mpg at about 85mpg.. he could feel me as soon as the drafting began.. soo... the person you try to draft will get pist off because it makes their car or truck unstable.

 

If tail gating is illegal, why don't law officers pull them over. It's not like there's a dearth of them. We should really mine that. That would bring in tons of extra city revenue.

 

I agree on the "dead zone" (in more ways than one) behind a big rig. I drafted in my old Bug behind trucks on 99, and the spot was about 10 feet behind and in the next lane (better to straddle the lane line, but that's going get the wrong kind of attention). As noisy as a Bug usually is, I cuold roll the window down and hold a normal conversation at 55 mpg. I could feel the "pull" into the low pressure area if I wandered a bit. I did it for about five minutes, traffic and sanity prevailed and I backed off.

 

Drafting will have no effect on MGP at highway speeds unless you, and the person who you were tailgating were going at least 80 (and that would counter the whole point of doing it). Perhaps if you were tailgating right behind a large semi at normal highway speeds it would make a small difference. However travelling 55-65 mph behind a passenger car isn't enough of a break in the wind resistance for you to vacuum.

 

I've got 63,000 miles on mine, and in that many miles you can get trapped behind a truck. I "tested the waters" once and I saw that at 20 - 30 feet behind a big rig I got a 5 mpg increase while in the flats. Going up a long low hill, the MFD showed 50-70 mpg instead of the usual 30 mpg or so. As observed by others, you must be in the sweet spot, and the spot moves around. The relative wind direction has a lot to do with it. And no, you don't need 80 mph to see an increase - I was doing 60 in a 65 mph zone. Apply the "close your windows above 40 -45 mph theory" and anything above that speed should allow an increase mpg. But in order to get any real benefit, you must tailgate for many miles for the gas savings to add up. In other words:

IT AIN'T WORTH IT

It's illegal (and for a very good reason).

A line from The Outlaw Josey Wales comes to mind: "Dying ain't much of a living".

I won't be polite and say please like some others here, just this: DON'T DO IT

 

I'm sorry... what is magic about the 80mph number? I can tell you with some certainty that drafting a big-rig at even 55mph can decrease air resistance substantially. And you don't have to be dangerously close to benefit (though the benefits obviously decrease with distance from the wind-blocker). Let me say that again - you do NOT need to be illegally or dangerously close to benefit. If you ARE dangerously close, even at reasonable speeds, the benefits can be huge. Close enough to the back of a big-rig, and your air drag is damn-near zero. Even at 55mph, air drag is your biggest energy waster.

No, I don't condone it. I just think that false information is dangerous and should only be used in special circumstances like when you wife asks, "how much did THAT Prius accessory cost?"

 

Actually the magic number is 70 from what research I read, but you have to riding the person's bumper to feel the effect. I like how you only cut and pasted part of my post and played devil's advocate for nothing.

 

Actually the leather option is better in this instance. (says the man with two young kids :lol: )

 

1. Why did you say 80 then?
2. What now makes 70 the magic number?
3. From personal experience AND research, it just ain't so. I'm talking about behind a truck here, not a compact sedan.

I'm guessing that you didn't actually like it. I only pasted the part on which I had intended to comment. I guess the first part of your post assumed drafting a small car?

Here. Let me get the rest of it for you:

No...it can and does make a significant difference.

This is correct from what I've expienced, and certainly from a physics point of view. If this was your main point, then I missed it.

I wasn't playing devil's advocate, and I honestly don't believe it was for nothing. I was countering your statements with my contrary experience. Sorry to have offended.

I still don't recommend that anybody drafts. I only wanted to point out that it CAN make a huge difference, even at reasonable speeds.

 

i have felt the effects of draft at 40 mph. fact is, when behind something that is over 3 times your height and nearly double your width, there is a very nice pocket to get in.

but even if you get an extra 20 mpg, it wont come close to that $150 ticket that the WA state hiway patrol has been doing emphasis patrols on since last spring when the laws concerning this were stiffened.

 

Yes, yes, and You betcha.

 

I am fortuante that my 13 miles commute to work has ZERO interstate. Half country roads, half city streets. When I go traveling (read vacation) I am a "ble highways" kinda guy. I loathe interstate driving.