Reverse drafting: how to slow down on the hwy and not hold up traffic

[MetroMPG]

As everyone here knows already, probably the simplest way to increase your fuel economy significantly is to reduce your highway cruising speed (NRCan quotes about a 1% increase in consumption for every 1 km/h over 100 km/h).

Despite this fact, I have noted that people sometimes instinctively recoil from the suggestion, citing "going with the flow" as the reason.

I often wonder how much of the objection stems from the practical (ie. actually significantly disrupting traffic flow), and how much is psychological (the stress generated by the inevitable tailgaiters, who inattentively ride your rear bumper for a while, then "wake up" and roar past).

Regardless of the root of the objection, my prescription for people who are sensitive to the issue of slowing down is this:

Enter the freeway at your usual pace, and drive as normal until you pass a transport or other large vehicle in the right lane which is driving slower at a steady pace. Change to the right lane in front of that vehicle (keeping a respectable gap of course). You are now free to drive at the reduced pace of the vehicle behind you. You are no longer responsible for blocking faster traffic; it was flowing around this vehicle anyway.

It's sort of "reverse" drafting: they're breaking the flow for you - not of air, but of faster traffic approaching from behind, and you're capitalizing on that to improve your fuel efficiency.

[MetroMPG]

Sure, but what do you do when the truck (if it's a truck) speeds up going down hills?

I didn't say so in my original post, but I adjust my speed to match the vehicle I'm reverse drafting, including trucks behind me on hills. Common courtesy.

I also speed up for trucks approaching from behind if I'm driving slower than average - solo - if they don't have an immediate opportunity to pass me. Once they're by, I drop down again.

And this strategy may not be practical using heavy trucks on hilly roads.

[TomO]

It's good advice to follow. The hard part is getting people to see the light that all the little things add up into something palpable.

Every road I drive on has two lanes of traffic going in the same direction. I always stay in the right lane and go the speed limit. The highest speed limit on my route is 65MPH. I will go up to 65 since it's only for 2 minutes of my commute. The rest of my trip is spent at 55MPH. Even going the speed limit I'm passed often. The only thing is: I don't feel bad for making people have to pass me since A) They are the ones going beyond the speed limit, B) They have a passing lane and have plenty of time to see that I'm not speeding since there are no hills on my route, and C) They have a chance to see my license plate frame "My car is slow but 50+MPG".

If there ever is a semi barreling upon me, even above the speed limit, I will make sure that they are able to pass easily.

Also, when I get passed by a semi and they want to get in front of me, I make sure to signal to them by blinking the high beams twice. I always get a great response from the truckers with the parking light flash from them. I also do this to let them know I see them and it is safe to pull in front of me from a merging/on ramp lane.

[MetroMPG]

Your post is more evidence that proves ecodrivers/hypermilers have an above-average awareness of what's going on around them.

We may drive differently, but we're considerate, and the awareness of traffic probably makes us safer than average.

[Palionu]

Despite this fact, I have noted that people sometimes instinctively recoil from the suggestion, citing "going with the flow" as the reason.

I purposefully drive 65 or under because I love looking into my rearview and seeing the people swerve to look around as their faces turn red.

I often wonder how much of the objection stems from the practical (ie. actually significantly disrupting traffic flow), and how much is psychological (the stress generated by the inevitable tailgaiters, who inattentively ride your rear bumper for a while, then "wake up" and roar past).

If the tailgating irritates me or if I anticipate it I just adjust my rearview mirror so I simply don't see them. They usually just zoom past me and give me a dirty look while I laugh.

[Palionu]

Originally Posted by MetroMPG

Your post is more evidence that proves ecodrivers/hypermilers have an above-average awareness of what's going on around them.

We may drive differently, but we're considerate, and the awareness of traffic probably makes us safer than average.

whoops...

/me runs and hides.

On a normal note, I am considerate but I get over when it's safe for me, not when it's convenient for them.

[cfg83]

MetroMPG -

I am definitely in the "go with the flow" tailgater stress excuse category. Your idea is interesting, but for me, I would still drop in behind the slower vehicle. Once I am behind a slow-poke, I stop worrying about tailgaters because they can't blame me for driving slow . Also, it's easier for me to follow a slow-poke than it is to keep tracking their speed from in front.

CarloSW2

[claytori]

It seems to me that reverse drafting is inconsistent with attempting max fuel economy. It is always better to follow another vehicle than to lead and have to "break wind". If you are going at the same speed anyway, why not follow and gain the draft? Ever try bicycling over a distance in a group? The lead rider tires quickly and must drop back. Let the guy ahead buy your fuel.

[WaxyChicken]

On the way home from work, when the freeways are alot quieter, i have started going over to the slow lane and then using CC to let my car keep itself at 55mph. It may be bad to use C. Control, but if it keeps me from doing 65 on a dead highway than why not?

[trebuchet03]

I missed this thread

Funny thing is - despite whatever some ass might tell you about truckers "feeling" parasitic losses from tail gaters... There is a very slight aero advantage when there's someone behind you as their high pressure fills in your low... Of course, someone in front is better - someone behind is okay - worst possible scenario is no one around you...

In fact, iHPVA rules state that chase cars must be at least 200' (not 100% sure on the exact number) behind the HPV on the course due to this advantage