Does a tailgater fill your wake? :)

[deejaaa]

Originally Posted by euromodder

When you're the one following, right ?

........

yes, as far back as 25 feet.
i don't see any benefit when someone is tailgating me. it just upsets me.

[RedDevil]

The draft wake of a semi extends much further than just 25 feet. I can see the effect at 50 meters, my usual drafing distance.

Ever stood close to a road on a windless day when a semi passes at speed?
You can feel the wake wind blow for 3 or 4 seconds after the semi went by.

[christofoo]

Back to the OP's original question, tailgaters should never be viewed as doing you a favor, aero or otherwise.

In aerodynamics, although the trailing car sees some benefit at not-entirely-unsafe-distances, this is relatively untrue from the lead car's point-of-view.

(This is from aerohead's magnificent trailer gap reference post that I keep citing.)

In terms of liability, I think traffic officers will almost always find the trailing car at fault for a rear-end, but I wouldn't take it as a given unless you run a dash-cam-DVR, i.e. you can prove that you did not swerve and/or brake-check. I see it as a big headache at best, also an opportunity to meet and greet with the most hot-headed segment of the population.

[California98Civic]

As I read that image of lead and trailing cars, it suggests that the lead car benefits substantially, by nearly .09 in Cd at the closest range represented without practically touching bumpers.

[Xist]

Christofoo, thanks for sharing that! I had seen it before, but must not have paid attention!

[ecomodded]

Much like geese , where the lead goose and his close friends get the easiest and lowest drag flight position , the geese swap positions so every goose benefits in the end.. Hey I think I see Packs of speeding cars doing this all the time , if only by accident , pun intended.

[Hersbird]

I was traveling with my son in law following for 3 hours on the highway and I picked up 2 mpg from what we had averaged the week before with nobody consistantly following. He wasn't that close, but my daughter told him a few times to back off so he was closer then 2 secs.
In stock car racing everybody gets their drag reduced, frobt, middle, back. On the highway it's not going to be as drastic but now I'm happy to see a follower.

[ecomodded]

Until he misses the driver 1 up from you who in his stupidity stops hard & fast for a squirrel stopping on the road , and Slams into your rear end at 65+ mph.


We never plan on having an accident but a tailgating really does make having one much more probable and painful.


The tailgater is no small threat to a life , he is in a position to compact a already compact car with someone or a family inside of it ... Makes much ore sense to buy a awesomely fuel efficient economy car , that does not require drafting to 'get ' some acceptable gas mileage.

Play it safe and safety follows instead of the other way around ,..

[freebeard]

Hucho via aerohead

www.youtube.com/watch?v=00zd8g1jQ-E

[Hersbird]

I guess what is the definition of a tailgater? I still say there is a benefit for both front and back at a normal rush hour following distance and even something at the 2 sec distance. Actually tailgater's often pay close attention to what the car in front is doing and if you think about it, in the even of a panic stop the differential in speed would be less because the car in front can't get to zero before the collision happens. If they are following back further an all relaxed not paying attention, the car in front can make a full stop and a full speed collision can happen. I normally don't tailgate because I like to set cruise and not have to mess with speed adjustments but if somebody drives behind me I'm OK with that also.