Drafting: stream of cars vs semi

[palemelanesian]

3 seconds - about the time it takes to fully speak, "American Automobile Association".

[99metro]

Originally Posted by JanGeo

Yeah and even a couple of trucks side by side is really great. They actually get the air moving in their direction behind them. I find it really interesting how as a big vehicle comes up beside me how my car first turns into their lane as their bow wave air pushes my cars back end sideways. Then as they pass my cars nose gets sucked into their wake. The force is strong with trucks . . . master.

My thoughts exactly. I like having two slow moving trucks side by side and me behind.

[FLAteam]

Originally Posted by 99metro

My thoughts exactly. I like having two slow moving trucks side by side and me behind.

That happened to me last night, only it was even better. I had a chartered bus in front of me going about 75mph and a semi to the right lane in front of me and a semi behind me. I was able to hit about 39mpg average for about 5 miles of this before it all fell apart. The total trip, however, was about 50 miles at the time so I imagine that I was getting even better mpg instantaneously.

This morning I was going about 65mph behind an RV and I only got up to 37.1mpg after driving 15miles, the total trip being about 50 miles again.

I'm starting to think that vehicles that are lower (like minivans) are better for drafting than semis!

[1cheap1]

There are plenty of container trucks on the 710 long beach freeway here in socal. Most do 55 or slower. Its best when i am behind one, one to the left of me and one behind. I am in the cradle, so to speak. I can eoc in the draft and helps get me to max mileage. On the 405 are mostly passenger cars. I just go 57 and set the cruise control and wait for something to draft.

[R.I.D.E.]

3 stripes is my minimum, which is very close to my stopping distance between vehicles, about 130 feet at 60 MPH.

I am learning more with the Insight, because it has the bar graph that shows me instantaneous fuel mileage.

Best for me is a large motor home with the rear lower portions that extend down close to the ground. After a motor home the best big rigs are the tandems that have a hitch mounting point for the second trailer that extends down much closer to the ground.

The other big rigs seem to have much more airflow under the trailer.

I drive the speed limit, which means almost everyone is passing me. I just wait for the best opportunity for drafting. With the .25 CD of the Insight drafting is not as important as it was in the VX, so my drafting is much less agressive than it used to be.

3 stripes in the right lane also gives me the escape route to the right on the shoulder of the road if I encounter a large piece of debris, without having to worry about traffic blocking my escape route.

regards
gary

[bobc455]

When I watch NASCAR (who also is big into drafting), it seems like it is only necessary for two cars to be together to get some good draft action going.

-BC

[theholycow]

At NASCAR speeds, NASCAR following distance, and probably helped by NASCAR aerodynamics (especially that rear spoiler), the effects of drafting are highly exaggerated as compared to the effect of highway drafting.

Also, although I mentioned following distance, some here have measured a less effective draft when tailgating as compared to a reasonable distance; I suspect that NASCAR following distance only works with race car aerodynamics and highway cars suffer at that distance.

Today while EOCing downhill into my exit ramp, a tailgating big rig passed as soon as I entered the exit lane. I definitely felt the aerodynamic effect; it felt like I hit a heavy gust of head-on wind and slowed the car, but I think my butt dyno may have been misadjusted. I felt it around the time the steer axle of the truck was somewhere next to my car.

[Geonerd]

Several have mentioned having a in front and a truck behind them, as well. Do you have a death wish?? Saving a few oz of gas is nice, but is it worth getting squashed like a bug? Truckers enjoy great visibility (assuming the driver is alert enough to use it!), but a semi simply cannot stop as quickly as your car. If a pileup of any sort occurs, you're toast.

In a more general sense, many hypermiling techniques will produce accelerated wear and tear on your car. Anytime you stop the engine, you're cycling the ignition switch, starter or clutch, and collapsing the oil film that keeps your engine alive. Even a warm start will generate far more wear than simply leaving it to idle.

Evey time I see a video of King Hypermiler Wayne, I think, "That guy has obsessive-compulsive issues!" (He jams the car in into drive immediately after a cold start; he putts down the road trailing a dozen pissed off commuters, etc.) Yet time and time again, I see people wanting to do it just like he does, to achieve the same level of FE. Think people, THINK! As with anything in life, blind pursuit of an objective seldom works out in the long run. Go save gas, but try not to destroy your car, yourself, or the sanity of your fellow motorists in the process!

[theholycow]

Originally Posted by Geonerd

Several have mentioned having a in front and a truck behind them, as well. [...] Truckers enjoy great visibility (assuming the driver is alert enough to use it!), but a semi simply cannot stop as quickly as your car. If a pileup of any sort occurs, you're toast.

Actually, that particular technique doesn't sound so bad. If a pileup occurs, the trucker in front has great visibility and can't stop as quickly as your car. The trucker behind has better visibility than if you weren't there and he was closer to the other truck. Therefore you need only stop as quickly as the front truck, and the rear truck will be able to stop without crushing you...assuming the driver isn't "livin' on reds, vitamin C and cocaine".

That said, you still won't catch me doing it. If the feces does hit the multi-bladed air circulating machine, the consequences are dire.

King Hypermiler Wayne

Is that the extremist who is often shown on the news with his stock Honda Accord getting something like 75mpg?

[Jay2TheRescue]

Originally Posted by theholycow

If the feces does hit the multi-bladed air circulating machine, the consequences are dire.

[Stern mother voice]
What's all that potty talk young man?
Do I need to wash your mouth out with soap?
[\Stern mother voice]