Drafting - pros & cons

[Cd]

So I saw this gasoline tanker cruising along and thought I would give chase.

[UFO]

Originally Posted by MetroMPG

The biggest danger in following too closely isn't necessarily the stopping distance in front of you (assuming you're not napping at the wheel).

Following too closely makes you a reactive driver, instead of a driver that anticipates based on what is happening down the road. It's even more true if you're following a big vehicle that you can't see past.

When you're too close or can't see, you're more at risk of being run into by the driver behind you because you have to brake as hard and as fast as the vehicle in front.

I'd rather use a big safety cushion in front to absorb changes in speed more gradually, and give the tailgaiters behind more time to aviod smashing into me & each other.

Very good points to consider.

Again, regarding the reaction time again, it is extremely challenging to maintain a hair-trigger on your brake for any length of time. I've done drag racing so I know how difficult it is to keep focus even for a few seconds before the tree drops. If you want to draft for more than a minute or two, I guarantee that drafter's reaction time will extend to 1 second or more. That can be deadly.

[silverinsight2]

Originally Posted by UFO

Very good points to consider.

Again, regarding the reaction time again, it is extremely challenging to maintain a hair-trigger on your brake for any length of time. I've done drag racing so I know how difficult it is to keep focus even for a few seconds before the tree drops. If you want to draft for more than a minute or two, I guarantee that drafter's reaction time will extend to 1 second or more. That can be deadly.

Why draft so close? You can get a portion of the effect further back and it's a lot safer.

[UFO]

Originally Posted by silverinsight2

Why draft so close? You can get a portion of the effect further back and it's a lot safer.

Drafting behind a big rig will improve your car’s fuel efficiency.

confirmed

To test this myth, the build team procured a car, a big rig, and a device that could measure a car’s fuel efficiency. They then drove the car behind a moving big rig at various distances ranging from 100 to 2 feet and measured the amount of fuel the car consumed. The Build Team discovered that the closer the car was to the big rig, the less drag is produced, thus the more fuel saved. At just ten feet, the car managed to increase its fuel efficiency by 40%. Drafting at two feet was slightly lower than the ten foot distance, mainly because Grant had to keep working the car pedal to maintain distance from the truck. However, that did not dispute the fact that drafting actually can increase your car’s fuel efficiency. However, the Build Team has warned that drafting is incredibly dangerous because the truck driver may not able to see you and you may not be able to react in time if the truck were to make a sudden stop.

11% at 100 feet with a 1 second reaction time. Good luck with that.

[Bow]

I do it... Well, I use too in Texas (no freeways up here in Southern Maryland...)

But I'd jump on the CB and ask the driver if he'd mind me sliding in behind him and saving some gas...

99% of the time, they didn't care, and on a long run, we'd strike up a conversation.

I ran from Houston of Oklohoma City like that in my '91 240SX fastback. Running 85 mph, A/C on, no cruise control, and drafting, we got 45+ MPG.... the wife was snoozing and I was BS'ing with the truck driver...

Bottom line, if you ask, they are usually cool with it, and will warn you if there is something coming up in the road....

[HighMPG]

Originally Posted by Bow

I do it... Well, I use too in Texas (no freeways up here in Southern Maryland...)

But I'd jump on the CB and ask the driver if he'd mind me sliding in behind him and saving some gas...

99% of the time, they didn't care, and on a long run, we'd strike up a conversation.

I ran from Houston of Oklohoma City like that in my '91 240SX fastback. Running 85 mph, A/C on, no cruise control, and drafting, we got 45+ MPG.... the wife was snoozing and I was BS'ing with the truck driver...

Bottom line, if you ask, they are usually cool with it, and will warn you if there is something coming up in the road....

This brings back some memories when my pops had one in the jeep, I was like 8 and would hop on and start scanning channels for people to talk to. It also reminded me of "Smokey and the Bandit" and"Knight Rider" "Air Brakes" to slow down from super pursuit mode. lol

[pmiulian]

I did use this technique and didn't seem so dangerous - except for the flying rocks part. Longest run was for about 25 miles at constant speed of about 55 mph. I kept a distance of about 20 - 30 feet. I didn't measure the mpg, but overall I had a good FE for that trip.

[Clev]

When I had my long commute, I used to do that on the 60 freeway. Of course, all traffic was moving at 45-55 mph, and I'd stay several car-lengths back. My concern wasn't so much that the truck was going to slam on his brakes, but that he'd see a wooden apple box or something and just high-center it, leaving me to eat it. However, since he was following other cars, it seemed less of an issue. (I could tell if they were swerving out of the lane to avoid something.)

[pmiulian]

I don't know if it makes a big difference or not, but if I decide to draft behind a big truck, I check to see if it has wheel spats, so that rocks or pieces of wood don't fly right up.

[Arragonis]

2 second rule. If you can say "I always follow the 2 second rule" in the time it takes the vehicle in front to pass a fixed point and for you to reach it, thats safe.

Big trucks make a big hole, you can be safe and still gain.

Plus being further back means your window is less full of truck, so you get to see more of the road ahead.