That's the point. Even if 75 mph it's the legal maximum speed in most highways (in Europe even more), I don't want either to drive at 55 mph in a highway where all the car's drive at 75 mph.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
That's the point. Even if 75 mph it's the legal maximum speed in most highways (in Europe even more), I don't want either to drive at 55 mph in a highway where all the car's drive at 75 mph.
diamond.g
Active Member
I find that there is a huge difference drafting someone at 75 MPH vs having no one in front of me. In my TDI I can get 48-50 avg mpg if I draft, 38-42 avg mpg otherwise. It is likely that would help the Model 3 eek out some distance.
SageBrush
REJECT Fascism
The killer app for auto-pilot may be controlled drafting, but stand-alone like you do is really, really, foolish.
diamond.g
Active Member
I do when a person is going 20 in a 40 with no ability to pass. Maybe you might call that tailgating... haha
SageBrush
REJECT Fascism
If you are close enough to improve your fuel economy by 20+ percent you are way too close.
Just consider that it will take you at least a good half second to respond to traffic changes in front of you. At 70 mph that is already 50 feet. A very miserly one second interval is 100 feet ...
Last edited:
diamond.g
Active Member
fair enough. I know that this morning even though we were all doing like 70-75 on I95 my average speed was closer to 60mph, so it is possible that I am going far slower than I think for a lot of my trip and just don't notice. This afternoon won't be a good test, cause it is friday and traffic is horrible on fridays...What would be the average % gain if I followed at a safer distance?
SageBrush
REJECT Fascism
I frequently run the gauntlet of The 5 between the Bay Area and LA. I intially wanted to believe 'drafting' ( = the nominal separation in heavy-ish freeway traffic, for all you safety nazis...) helped my range.
After more experimentation, I've found that following vehicles (again, at a safe distance) makes almost zero impact unless you're behind a bus or big rig. You'd be lucky to see a few miles improvement in a leg. Clicking down 1mph in open road cruising has at least the same effect, if not more. Managing your speed relative to head/tailwinds has significantly more effect.
diamond.g
Active Member
@SageBrush what @bxr140 replied with answered my question.
So the correct thing to do is slow down (which has bee repeated a bunch) if you are in danger of not making the next SC/Charger/Destination.
Like I said, a big truck or a bus does make a difference. You'll also see a gain from slowing down to match the speed of your rabbit, so don't apply all the savings to the draft itself.
SageBrush
REJECT Fascism
By my arithmetic -- the truck is over a football field in front of you calculating from 60 mph.
I'm surprised by your observation
voip-ninja
Give me some sugar baby
Yes, aerodynamics don't back up that assertion at all. Drafting Behind Trucks: Does it Work?
At 60 mph and 5 seconds behind you are;
5280 / 60 * 5 = 440 feet away. Should be very little if any draft effect.
Good rule of thumb is that minimum safe distance at highway speeds is 2 seconds, for today's texting distracted drivers, or when conditions are less than ideal, 4 seconds.
I am highly skeptical of any fuel economy gains 5 seconds behind someone ... No matter how big the other vehicle is.
That sounds about right.
I am generally speeding up to keep up with them.
Thank you kindly.
BTW, the 0.7 factor in the formula I referenced doesn't just account for low temps, but also normal driving speeds. I don't think anyone who orders M3 plans to drive it like a Leaf. Besides, 215 is the bare minimum EPA range announced. So much can change between now and launch. Keep in mind that the apples to oranges comparison won't just magically go away once the Bolt is launched. I guarantee you that Elon will pay attention (and adjust accordingly) to what real world range Chevy (or any other manufacturer) actually ends up with prior to M3 launch. M3 absolutely has to be the range champ for the money.
Oh, and don't forget the biggest and most important factor of them all... there will be an optional higher capacity battery, perhaps even more than one!
Oh, and don't forget the biggest and most important factor of them all... there will be an optional higher capacity battery, perhaps even more than one!
SageBrush
REJECT Fascism
Mythbusters did this a while back and found something like 10-12% gains at 100ft distance (6-7 car lengths) behind a tractor trailer. No way you're getting that at 300-400 feet.
Another significant detriment to gains from drafting is a crosswind. If there's any appreciable crosswind, your gains are lost as the wake is blown to one side or the other.
I'll happily admit that I did not do a scientific study, it was merely casually observed anecdotal evidence. Perhaps you can explain how you extrapolated for one data point to an impossibility.
Thank you kindly.
Similar threads
