Aeromod nissan leaf improved aerodynamics increased range

[VitaminJ]

So far I am averaging about .5 mi/kwh more than before the mods. My commute is mostly 45-50mph and some burst up to 80mph and some sections at 30mph. Any air that travels through the grill opening will cause turbulence and drag in the engine bay, effectively increasing the frontal area. By blocking off the grill, the frontal area of the car is lowered. The tire deflectors work by decreasing the coefficient of drag, but that's much less of an effect.

 

[Reddy]

^^^^Thanks for the update. Hmmm, every winter I should probably add that grill block. It would help a bit, but probably not a big improvement for my short, 2-5 mi trips in town with a 20 mph avg speed. Still, with my energy hogging heater, it might reduce some of that consumption.

 

[LeftieBiker]

^^^^Thanks for the update. Hmmm, every winter I should probably add that grill block. It would help a bit, but probably not a big improvement for my short, 2-5 mi trips in town with a 20 mph avg speed. Still, with my energy hogging heater, it might reduce some of that consumption.

Have you insulated the heater tank and lines? The two together might help a lot.

 

[Reddy]

Have you insulated the heater tank and lines? The two together might help a lot.

Yep, did that as soon as I read about here

 

[VitaminJ]

I drove over an hour and finished the drive with a few miles of 75+mph highway a couple times now and even with the grill block nothing in the engine bay is too hot to touch. Little warm but not hot. Ambient temps 75F. Loving these free miles.

 

[GetOffYourGas]

I'm guessing you'll be fine with that grill block until you try to run the A/C on a hot day. Other than that, the Leaf shouldn't be doing anything to dump much heat in there.

 

[lorenfb]

I drove over an hour and finished the drive with a few miles of 75+mph highway a couple times now and even with the grill block nothing in the engine bay is too hot to touch. Little warm but not hot. Ambient temps 75F. Loving these free miles.

Now paint the upper part (above the chrome strip) black, i.e. it'll look much better - Tesla like.
Do a PhotoShop on the image to get an idea. A non-black color in that area always makes the Leaf
appear to have an "overbite" problem.

 

[VitaminJ]

I'm guessing you'll be fine with that grill block until you try to run the A/C on a hot day. Other than that, the Leaf shouldn't be doing anything to dump much heat in there.

I actually used the AC last week and nothing felt much hotter. It was mid 60s that day and only ran the AC on low. I will be cutting out a section of the block in front of the AC condenser when the weather warms up. Might be sooner than planned, it's not very February-like right now. 70s and 80s :?:

Now paint the upper part (above the chrome strip) black, i.e. it'll look much better - Tesla like.
Do a PhotoShop on the image to get an idea. A non-black color in that area always makes the Leaf
appear to have an "overbite" problem.

Does that also improve the range? :mrgreen:

 

[GetOffYourGas]

I'm guessing you'll be fine with that grill block until you try to run the A/C on a hot day. Other than that, the Leaf shouldn't be doing anything to dump much heat in there.

I actually used the AC last week and nothing felt much hotter. It was mid 60s that day and only ran the AC on low. I will be cutting out a section of the block in front of the AC condenser when the weather warms up. Might be sooner than planned, it's not very February-like right now. 70s and 80s :?:

I was thinking much hotter than even 80s. Like summer in Arizona. Because that's what the A/C and corresponding air intake was designed to handle. I would venture to guess that in my climate I could get away with a grill-block 12 months of the year, with no real damage to anything due to excess heat (assuming, of course, that heat doesn't make its way to the battery).

 

[lorenfb]

To develop validity in regard to any real overall energy loss improvement, i.e. increased range, via aerodynamic
improvements, robust tests in the form various speed tests over a two to three run on a flat terrain while
accurately measuring energy usage are required. Without that, any real beneficial effects from aerodynamic
improvements are basically conjecture.

 

[VitaminJ]

Guys, sounds like the record is jumping again. Can someone please fix that?

In order to find a stretch of flat road more than 1/4 mile long I would have to drive 100 miles or something. Luckily the car automatically records it's energy economy, miles driven, and many other data points every day and uploads them to servers via it's 3G modem. Using the handy website Nissan created you can even graph these values and compare them to historical values. That's pretty cool stuff, huh!? I plan to use this data to show that my mods do increase range. I need another week of commuting and then I can show the data. It is not as precise or as clean as doing the tests on a vacant, flat road with back to back tests, nor is it as good as a manufacturer's wind tunnel and computer model testing. However, it is good enough for an amateur who likes to tinker with his toys and it is free, because I drive to work every day regardless and the car records the data regardless and I will find it interesting. Frankly, I should just enjoy the bump and ignore the internet trolls who like to cross-examine and hold to the highest standard possible everyone who has an inkling to log off the computer, go into the garage, and turn a wrench.

lorenfb, you won't be interested in the next few sentences so please stop reading here. Everyone who is interested, my gain has stabilized at around .5 miles/kwh increase in economy. I run my tire pressures at 47psi cold and they stabilize about 49-50 psi during the drive. The gain is there regardless of outside temperature or heater use when I track my efficiency against temperature.

 

[jlv]

To develop validity in regard to any real overall energy loss improvement, i.e. increased range, via aerodynamic
improvements, robust tests in the form various speed tests over a two to three run on a flat terrain while
accurately measuring energy usage are required. Without that, any real beneficial effects from aerodynamic
improvements are basically conjecture.

I couldn't say it any better.

 

[VitaminJ]

I couldn't say it any better.

Thank you for your valuable and helpful contribution!

Just to be clear, lorenfb and jlv have done nothing in this thread except try to come up with reasons why aeromods like grill blocks and tire deflectors (which are things that manufacturers have implemented in automobiles since....oh I dunno 1930 or so!) don't do anything at all and are a waste of time and effort. These two, and a few others like them, fill up thread after thread with meaningless drivel that both doesn't help anyone and is supposed to be some sort of "voice of reason." lorenfb and jlv will make post after post with no information, no unique thought, no experimentation and will try to put that on the scale against people who actually try something, are doing the best they can in their free time with basic tools, and offer it freely to a community. They think they are practicing "science." In fact all they are practicing in pessimism and they have nothing to contribute but negativity.

Grill blocks and tire deflectors are things that have existed nearly as long as 4-rubber-wheel transport has existed. These basic concepts of aerodynamics are thoroughly documented from the halls of NASCAR to the top secret files of NASA. Weekend warriors practice these modifications on their amateur racecars, GM uses these techniques on their Volt and Bolt, Tesla on their cars. 18-wheelers implement them on their rigs. This is not some alien and extraordinary claim. Blocking the grill and deflecting air around tires makes a difference, plain and simple.

You're free to sit in your chair, lean back, and type some more useless, needless, helpless, negativity...in the meantime my Leaf will drive further than yours nananaaa booo boo.

 

[lorenfb]

Remember with regard to Leaf energy losses, up to about 45 to 50 MPH the rolling resistance losses and the drag
losses are about equal. After that, the drag losses increase exponentially with speed, but the rolling resistance is still
a factor. Yes, increasing tire pressure to a certain extent will help a little to reduce the rolling resistance, but its effect on
the coefficient factor is minor when combined with the Leaf's overall weight. Without major overall Leaf body re-design,
very minor effects to the coefficient of drag can be achieved. Again, only a robust analysis, i.e. using a scientific
methodology, can provide a valid proof for the effectiveness of body mods.

 

[lorenfb]

In order to find a stretch of flat road more than 1/4 mile long I would have to drive 100 miles or something.

Not really a 100 miles, a small sample of multiple runs of about 10 miles in total will provide indicative data
and possibility indicate how well the test is functioning.

Luckily the car automatically records it's energy economy, miles driven, and many other data points every day and uploads them to servers via it's 3G modem. Using the handy website Nissan created you can even graph these values and compare them to historical values.

If I'm not mistaken, that data when calculating efficiency considers coasting as does the GOM in calculating
range. Without knowing what the methodology being used by the Leaf and Nissan, the results become questionable.

Again:

To develop validity in regard to any real overall energy loss improvement, i.e. increased range, via aerodynamic
improvements, robust tests in the form various speed tests over a two to three mile run on a flat terrain while
accurately measuring energy usage are required. Without that, any real beneficial effects from aerodynamic
improvements are basically conjecture.

 

[VitaminJ]

Remember with regard to Leaf energy losses, up to about 45 to 50 MPH the rolling resistance losses and the drag
losses are about equal. After that, the drag losses increase exponentially with speed, but the rolling resistance is still
a factor. Yes, increasing tire pressure to a certain extent will help a little to reduce the rolling resistance, but its effect on
the coefficient factor is minor when combined with the Leaf's overall weight. Without major overall Leaf body re-design,
very minor effects to the coefficient of drag can be achieved. Again, only a robust analysis, i.e. using a scientific
methodology, can provide a valid proof for the effectiveness of body mods.

Yes, I am going after minor effects. That's the whole point of modifying a car; all the big stuff the manufacturer has already addressed, so there are only small details that I can make adjustments to.

My efficiency claim is .5 miles/kwh increase over what the car normally does. If we take a base efficiency of 4mi/kwh and an average capacity of 20kwh to keep it simple, then this is a gain of approximately 10 miles of range. 4 * 20 = 80 miles, 4.5 * 20 = 90 miles. This is approximately 12% increase in driving efficiency. I am not claiming my Leaf can now drive 200 miles, I am making a modest claim; a claim which is not unreasonable if one takes a look at the hundreds and hundreds of documented hypermiling enthusiast websites and forums.

My scientific methodology is comparing a daily driven commute before and after a modification. Luckily, increasing efficiency doesn't have to be categorically proven in order for the benefits to be experienced. If there is an efficiency gain, my car will experience it regardless of it I am able to prove it beyond any question of a doubt to you here on this forum and it will manifest itself in more miles driven per kwh.

Not really a 100 miles, a small sample of multiple runs of about 10 miles in total will provide indicative data
and possibility indicate how well the test is functioning.

You misunderstand. Due to the terrain in my geographic location, I would have to drive 100 miles away from where I am now in order to find a stretch of road that is flat for more than 1/4 mile at a time. It is not feasible.

If I'm not mistaken, that data when calculating efficiency considers coasting as does the GOM in calculating
range. Without knowing what the methodology being used by the Leaf and Nissan, the results become questionable.

Again:

The data recorded from the car that I am interested in is miles/kwh. This is recorded by taking the total amount of distance driven in a day and dividing it by the total amount of energy in kwh used during that same day. Unless the Leaf's efficiency meter is inherently wrong, then this data is as best as we can expect. This is far more consistent than the GOM.

 

[lorenfb]

The data recorded from the car that I am interested in is miles/kwh. This is recorded by taking the total amount of distance driven in a day and dividing it by the total amount of energy in kwh used during that same day. Unless the Leaf's efficiency meter is inherently wrong, then this data is as best as we can expect. This is far more consistent than the GOM.

Just like with GOM data, total miles driven is distorted by any time the vehicle is coasting.
Thus the true energy per mile is distorted. One really needs just the true miles driven when the motor
is using energy to move the vehicle, i.e. acting solely on the energy losses of rolling resistance and drag.

 

[VitaminJ]

Just like with GOM data, total miles driven is distorted by any time the vehicle is coasting.
Thus the true energy per mile is distorted. One really needs just the true miles driven when the motor
is using energy to move the vehicle, i.e. acting solely on the energy losses of rolling resistance and drag.

How is that distortion? When the vehicle is coasting it is using far less energy so of course the data will reflect that. If my journey is exactly the same every day using the same roads and the same speeds, small variables will be averaged out and a greater trend will appear. This is the same as measuring instantaneous MPG vs. average MPG over a full tank of fuel. I am not measuring instantaneous mi/kwh, I am measuring average mi/kwh over the course of a normal working day, which is 75-80 miles of commuting. Tracking my daily mi/kwh is the same as tracking my daily MPG, and aerodynamic improvements will be reflected in it. I am not sure why this is so controversial for you, have you not ever tracked your mi/kwh use and seen how it's affected by things like temperature, tire pressure, headwinds, etc?

 

[GetOffYourGas]

The data recorded from the car that I am interested in is miles/kwh. This is recorded by taking the total amount of distance driven in a day and dividing it by the total amount of energy in kwh used during that same day. Unless the Leaf's efficiency meter is inherently wrong, then this data is as best as we can expect. This is far more consistent than the GOM.

Just like with GOM data, total miles driven is distorted by any time the vehicle is coasting.
Thus the true energy per mile is distorted. One really needs just the true miles driven when the motor
is using energy to move the vehicle, i.e. acting solely on the energy losses of rolling resistance and drag.

???

When the vehicle is coasting, it has some kinetic energy that has already been put into the system via the motor. It will slowly lose that energy to rolling resistance and to aero drag.

In fact, in one of my college physics labs, we measured the aero drag of a matchbox car specifically by letting it coast, and measuring its deceleration. The rolling resistance is constant (independent of speed) and the drag is related to speed by a well known equation. It seems to me that this is a perfectly valid way to measure the effects of an aeromod.

 

[VitaminJ]

Thanks for the sanity check, GetOffYourGas.


Today I had my best driving efficiency ever. Weather was also the warmest ever since I've owned the car. As you can see I did 5.0 mi/kwh and my total distance for today was 82.5 miles without charging at all during the day. My commute is 35 miles each way, and then I ran a few errands during my lunch break that made up the next 12.5 miles. Leaf Spy showed me at 2.5kwh remaining so if I continued to do 5.0mi/kwh that would bring me to 95 miles It's not like I'm driving 30mph the entire time either, my maximum speed is at least 75mph and most of the mileage is on 50-60mph roads. I drive with traffic, and do not practice any hypermiling techniques that I wouldn't consider just good practice (not accelerate to red light, predict light changes, don't try to race up hills) and I use cruise control on a few sections just for convenience. It is far from flat, I have about 5000ft of total elevation change (up-down-up-down, not 5000ft straight up fyi) over the 70 mile commute.

How much of this is aero mods? I do not know, but I know that my previous best efficiency over the commute was 4.6mi/kwh and it was not as warm as today but it was 70F (today was 75F), and that was before my mods. Since my efficiency is so good I can afford to pull the grill block off and try and alternate weeks and measure efficiency with and without. The weather will need to stabilize first, 2 weeks ago it was 15F and this week it is 75F.