Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Drafting Impact on Efficiency?

Greg29

Member
Apr 26, 2019
95
46
Orlando, FL
On a recent road trip I decided to see the impact of "drafting" on my efficiency in order to skip a SuC. I found a truck going between 70 and 75 mph and followed it for about 50 miles using the closest (setting 1) following distance for TACC. Non-scientific for sure but I estimated a 20% to 25% or so improvement in efficiency during my study.
A police officer friend says there is no way TACC can follow closely enough to benefit from draft. That I needed to be closer than TACC would allow. I'm frankly not willing to follow any closer than that at those speeds.
What do the scientists on this forum say? Is there a rule of thumb following distance to benefit from drafting based on size of vehicle being followed?
 

DirtyT3sla

Member
Apr 17, 2019
548
591
Holly
Here's an "as scientific as it gets" study from myth busters. You can probably find the video on youtube. It was a huge savings.
myth2.jpg
 

Greg29

Member
Apr 26, 2019
95
46
Orlando, FL
Here's an "as scientific as it gets" study from myth busters. You can probably find the video on youtube. It was a huge savings.
myth2.jpg
Very helpful, thanks. If I had to guess I would say TACC 1 setting is about a 1 second following distance or about 100 feet at 70mph. Sound about right?
 

KArnold

Member
May 21, 2017
579
536
Columbus OH
I had a similar experience for about 60 miles. Simply anecdotal as I didn't write down specifics at the time but I remember arriving at the scheduled SC with 11% more SOC than I had planned. And I'm historically pretty good at getting a close "arrival SOC" plan with ABRP tuned to my car/conditions.
 

brkaus

Well-Known Member
Jul 8, 2014
7,908
6,404
Austin, TX
Remember part of the savings in many cases is the slowing down part.

I have set at 4 behind trucks when I was low and felt it helped. No measure though.
 

maximizese

Member
Jan 16, 2018
480
461
California
Unfortunately for my friend who drove his Bolt from southern California to Sedona, Az last weekend, he came across one of the biggest fears for EV drivers...no fast-charging available at a crucial stop. He called from Blythe after the Chargepoint DC charger was offline. I saw on the Plug Share app that EV Connect had a DC fast-charger about 1.5 miles away...that charging station wasn't working either. He had to drive back to the Chargepoint location and level 2 charge for almost 6 hours to make it to the next available EVSE. ABRP told him to charge to 81% SOC and to not exceed 76mph. He was bored out of his mind and asked me if he should leave at 78% SOC.

I told him to study his energy graph and to not exceed 76mph AND to draft behind a big box truck when he could. I told him he didn't have to ride the bumper or tailgate and that even following 5-8 car lengths would help reduce the air turbulence. At the halfway mark, he told him he had about a 14% buffer and he was amazed at how much of a difference going 65-70mph behind a truck made on his range. It was his 4th roadtrip over 3 years and he's thinking of waiting a few years before attempting another one...next time I'll loan him our Tesla.
 

Babaron

Member
Jan 24, 2017
233
149
SW Ohio and west central FL
I draft all the time and I can tell you from experience that it definitely has a noticeable positive impact on efficiency.

As mentioned, slowing down even a little also has a considerable impact.

NOTE: If not already installed, you should strongly consider paint protection film if you plan to draft a lot.
 

SSedan

Active Member
Jul 24, 2017
2,948
2,323
Greenville Wisconsin
Drafting definitely helps and you do not need to be dangerously close.

I can only guess anyone who doubts is either always in heavy traffic or is a fast driver in an unpopulated area and always out front.

It doesn't have to be a semi either, a minivan or SUV work pretty well too.
 

Snerruc

Member
Apr 16, 2016
985
1,413
Palm Bay
You can get a drafting benefit from vehicles other than a large truck. You will benefit from a pickup pulling an enclosed trailer, or even a large suv. Being in a train of vehicles also helps.
 

tomauto15

New Member
Dec 5, 2020
2
0
DFW
If you don't care about rock chips, by all means, get right up on that butt of the car in front. Be ready for a brake check from the vehicle ahead.

My favorite draft trailers are the liquid carrying trucks. A cylindrical trailer design gives absolutely the cleanest air to follow behind without any of the "buffeting" of a square trailer. It is a very smooth airflow.

https://www.wabashnational.com/imag...nd-sliders---1315x690/walker-1---1315x690.jpg





The downside, of course, is getting a face full of tractor-trailer bumpers. Not all trailer bumpers are built to the same standard...So is it really worth it?
 

Attachments

  • walker-1---1315x690.jpg
    walker-1---1315x690.jpg
    756.9 KB · Views: 3

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top