Drafting vs low speed

[Jesse]

Today I noticed something very interesting, probably based on my ignorance. I was in a hurry and decided to go with the flow of heavy traffic on a 70mph road, everyone was going about 80+. Thing is, I was behind an suv, and next to a semi. While going 80mph I was getting 70-90mpg consistently, even on slight uphills. The only time I would go back to seeing normal numbers at these speeds(40-45mpg) was when I would be about 60+ feet behind the suv I was behind. Mind you, everyone else was about 20-30 feet behind everyone else. I am assuming I saw this great of FE because of drafting.

Now the thing is this, I normally would have been an asshat going 60mph in the far right lane(3 lane freeway) and I am certain I would never have seen these numbers. Has anyone else tried this unsafe method?

[CigaR007]

It is better to follow a line of cars at a higher speed than to cruise on your own at a lower speed.

[basjoos]

If you do a radical aeromod to knock your Cd down into the 0.1's, then you wouldn't have to draft to get that mileage, you are literally drafting yourself, which is a lot safer and not dependent on the presence of other traffic.

[bwilson4web]

The lead vehicle, often a semi-truck, will steer to avoid running over road debris. It is not so easy for closely following vehicles.

Bob Wilson

[jamesqf]

Originally Posted by Jesse

Mind you, everyone else was about 20-30 feet behind everyone else...

Has anyone else tried this unsafe method?

Of course. It is the normal style of driving on most California freeways, where if you leave more than about 1.5 car lengths between you and the vehicle ahead, someone cuts in to the vacant space. So since whether it's unsafe or not, it's certainly unavoidable, why not make a virture of necessity, and tuck in behind a semi?

[user removed]

Originally Posted by jamesqf

Of course. It is the normal style of driving on most California freeways, where if you leave more than about 1.5 car lengths between you and the vehicle ahead, someone cuts in to the vacant space. So since whether it's unsafe or not, it's certainly unavoidable, why not make a virture of necessity, and tuck in behind a semi?

Think I read about it being called the "corridor effect". As james stated in this post the situation here is just about identical. I64 from Richmond to Hampton Roads was built in the late 60s and in spite of the over 4 decades of population growth, it is still 4 lanes divided (2 each way). In times of congestion the separation distances will get down to 2-3 car lengths and if you try to leave more distance someone will pull over in front of you to try to pass on the right. I have actually watched one idiot weaving through traffic that congested because the drivers will try to stagger their positions in the two lanes.

regards
Mech

[PaleMelanesian]

I tested in my Odyssey once. Drafting at 70 mph gave the same mileage as driving solo at 65. You don't have to be much slower to make up the difference.

[Pete]

i have a black belt in drafting cars trucks, I drive a Vespa 180 rally from Texas to California 2 and 1/2 trips, in the 70's. i can tell you for a fact drafting greatly reduces wind residence as when you are on a under power vehical going 70+ mph the only way i could do it was to laydown on the handle bars, when drafting trucks i could sit up and rest my back. first trip fuel cost was $7 for the 1500 mile trip!!

[SentraSE-R]

I used to commute on a 90 cc motorcycle. When the semis would pass me, they'd suck me up from 55 mph to 70 mph, and I could hold speed with them as long as I could stay within 1-3 car lengths of them.

Now, I never join the high speed tailgater conga line. It's insane to follow other cars at 70 mph with <1/2 second separation between cars. It's a massive chain reaction pileup waiting to happen. What I'll do is occasionally follow big vehicles in the lane next to me, staying a car length or two behind and to the side of them.

[Pete]

I agree because of the long vortex of a semi you can get far behind on narrow bike. you don't want to get behind a cattle truck the smell can stay on stream behind it for miles lol