How close does a car have to be to a big rig in order to recieve the benifits of drafting?

Question

Or is it more detremental if one is not close enough because the wind is hitting the car harder? I drive a small subaru. Maybe another thing to consider is how tall does the big rig have to be?

Answer 1

usually 10-20 feet will do however depending on conditions ie.size of rig and size of drafting vehicle cross wind temp. all have effect but there is a "sweet spot" those wich changes with these variables if you ride a motorcycle you can feel it around you and actually see it reflected in the speedometer and trottle,
but yes alas the fuel savings is not worth the risk it is very dangerous...but it sure is a neat phenomina to experiment with

Answer 2

In order to see any benefit, and the only benefit is reduced fuel consumption, you would have to be like a foot off his azz, like the rednecks do in NASCAR. Additionally, you would have to do this for hundreds of miles to see any appreciable reduction in fuel consumption. Drafting a semi for five or ten miles, even a hundred miles, would net you a savings of maybe a buck under the best conditions if you're lucky. That means that both you and the semi must travel at the same speed and the same distance apart and on level ground with no crosswind to disrupt the calm pocket of air behind the semi. In the real world, none of this happens all at the same time, and never for very long. As soon as he slows down and you pass him, there goes all your fuel savings as you travel at full throttle through the massive wall of displaced air coming off the front of his truck. The damage done to your car when you hit him, or at the very least by the debris his 18 tires throw at you will far outweigh any fuel savings. Next time you're on a road traveled heavily by semis, watch and see how many shredded tire treads you see off to the side. They're all from truck tires that separated at high speed. I've seen them come apart and sail 50 feet into the air. It ain't pretty. You don't want to get hit by one. Also, your engine needs airflow to keep cool, and the faster you drive the more airflow it needs. Drafting a semi and actually cutting your airflow at higher speeds is the exact reverse of what the car needs, so if you decide it's worth it to tailgate the semi, you can expect to overheat if you do it for long. Basically, it just ain't worth it, and you can do much better by improving your own economy driving. A truck driver would probably not notice if a Subaru went under his trailer. You don't really want to die unnoticed, do you?

Answer 3

There is no benefit in drafting. What minuscule amount of fuel savings you get by tailgating a semi, or any other vehicle, is highly outweighed by the increase in the chance that you'll become involved in an accident or ticketed for tailgating.

Too much air passes under a "big rig" anyway.

Answer 4

You can travel behind using the 2 second rule and be fine and take advantage of the draft. It is never advisable to tail gate. Safety is far more important than saving .2 mpg. You can also slow to 68 mph and see substantial mpg gains w/o drafting. That is more effective and safer. Be sure to drive in the right lanes and leave the left lanes for faster moving traffic.

Answer 5

Don't do it. Truckers hate it. In order to get the benefit you would have to be so close that if the semi hit his brakes you would smash into the back of his trailer.

Answer 6

you have to get really close depending on what type of car you have truckers hate it they will usually move over to signal you to pass. anyway you can usually tell because you can hear the wind moving over the car slow down insubstantially this is what gives you the benefits of drafting because there is less air resistance to your vehicle

Answer 7

as a truckers wife i can tell you i have seen first hand how truckers feel about this. usually after tapping his brakes a few times to get someone off his butt the husband will hit the trailer brakes to finally get them off his a**. the smoking tires usually gets the point across.

Answer 8

my husband drives a truck. Yes truck drivers hate this. It is not safe. You can hit them or if they have a blow out it will hit you. In the process it may also involve other drives and may even kill. think smart first

Answer 9

too close