Drafting

[Lloyd]

Yep sorry to duplicate.

 

[doug]

I had someone back into my driveway and smash the front of my X 1/9 many years ago.
They started to drive away but I heard the noise and ran out. The person in the SUV said "I can't be responsible because your car was too small to see."
(And it was in my driveway no less.)

Wow... I would not be happy.

 

[VolkerP]

I am glad to have sparked some discussion about the "cooperative roadster drafting" experiment here. By no means I wanted to suggest that someone tries something unsafe or even illegal on public roads. It is more out of scientific curiosity. Hell, the power meter in a Roadster gives a live reading of energy needed to move the vehicle! Very tempting.
Given that 30ft drafting distance is insanely dangerous but still not close enough - the experiment may be performed in a closed-off environment. Some airstrip or closed round course?

 

[NigelM]

I am glad to have sparked some discussion about the "cooperative roadster drafting" experiment here. By no means I wanted to suggest that someone tries something unsafe or even illegal on public roads. It is more out of scientific curiosity. Hell, the power meter in a Roadster gives a live reading of energy needed to move the vehicle! Very tempting.
Given that 30ft drafting distance is insanely dangerous but still not close enough - the experiment may be performed in a closed-off environment. Some airstrip or closed round course?

Maybe TG could do it?

 

[tennis_trs]

I once lived on a cul-de-sac where people frequently turned around in private driveways when they realized the road didn't go through.
I had someone back into my driveway and smash the front of my X 1/9 many years ago.
They started to drive away but I heard the noise and ran out. The person in the SUV said "I can't be responsible because your car was too small to see."
(And it was in my driveway no less.)

At the Washington, DC store grand opening celebration, the Roadster parallel parked in front of mine out in front of the store backed into my car when leaving (the valet working next door told me that they backed into my car twice before he stopped them and eventually got a business card for reference for me). Tesla replaced the license plate frame and I bent the plate back into shape; no significant issues. I've always hated parallel spots, but more out of concern of getting sideswiped than bumper-to-bumper contact. But I expected that someone driving a ridiculously expensive car would be more careful, at least out of respect for their own ridiculously expensive car if not out of respect for my ridiculously expensive car.

 

[NigelM]

Back to drafting:

I had to take a long drive today (about 75 miles each way) so I tried out a couple of small tests where I felt comfortable. I have no exact figures as I was concentrating on the driving and not on amp usage. I could feel the difference in power when drafting behind 2 different trucks just by actually lifting my foot slightly and still maintaining speed; glances at my amp numbers showed them going down. What I did worry about was the traffic in front of the trucks and found myself quickly getting very bored with looking at the back of a dirty truck. I gave up on the trucks but coming back I tucked in behind a mid-size SUV and the effects seemed to be remarkably similar. The big benefit was that I could still sort of see ahead of the SUV and so I wasn't worried about the traffic in front suddenly coming to a stop, and somehow it didn't seem nearly as boring as staring at the truck. Of course, trying to find an SUV that cruises at a reasonable speed may be easier said than done.

 

[TEG]

I don't try much at all to draft in the Leaf, but when I was driving the old EV pickup (with not good aero) I had to draft a lot.
I started to become picky about which vehicles I would draft behind. First off I would look for something with an up facing exhaust so I didn't get an intake full of diesel fumes. Then I would look for something relatively clean so I wasn't staring at the back of a garbage truck or rust bucket.
Sort of comical actually. I would creep along at 45MPH in the slow lane letting vehicles pass until I saw a suitable truck drive by and would "latch on".
Also, I would try to figure out which trucks would go furthest so I could stay behind them the whole trip. Things with local labels like a local furniture delivery truck were out as they were likely to get off on one of the next few exits. A long haul shipping company would be better as they are probably headed to the next state.

 

[Lloyd]

Related to this topic is the ability of Mercedes cars using their Distrinic option to follow other vehicles at a specified distance. The closest distance this allows is 100feet. Perhaps this technology could be enhanced to allow closer following distances?,

 

[DZCPA]

I have done some truck drafting when needed. Do not seem to worry if truck needs to slam on their brakes since they take so much longer to slow. I enjoy the trucks with mirror finish rear doors so I can see how cool I look driving a roadster!

 

[VolkerP]

Related to this topic is the ability of Mercedes cars using their Distrinic option to follow other vehicles at a specified distance. The closest distance this allows is 100feet. Perhaps this technology could be enhanced to allow closer following distances?,

To save a considerable amount of energy with drafting, you need to aggregate multiple cars in a chain and link them together with some kind of distrinic system. The problem is, how can all cars change speed in sync. If every car is locked on the car it follows, little delays in triggering the brakes require harder braking to keep the distance. The need to brake harder quickly accumulates through the chain of vehicles, until either the chain ends or the capabilities of a car are exceeded, resulting in bumper contact. Problem is exacerbated with higher speeds, more cars, and closer following distances. Problem can be alleviated by linking all cars in the chain to the leading car with some wireless signal.
Finding cars that go the same route and are equipped with that system will be prohibitive to introduce such systems (chicken-egg-problem).
The best working solution of saving energy by drafting closely behind each other is called a train

The idea of roadsters drafting (where the drivers control speed and distance) is, you can see traffic ahead/obstacles/the lead car through the shields of the vehicle in front of you. This should help.