Most efficient speed

Bonanzajohn

New Member
Joined
Jul 30, 2024
Messages
19
Reaction score
3
Cars
@024 Grand Touring
What is the best speed to make it home when have limited battery left? 55? 50?
 
What is the best speed to make it home when have limited battery left? 55? 50?
Hypermilers drive slowly to beat EPA numbers.

Since you gave 2 choices, I would pick 50mph.

I usually don't leave until my battery gauge has at least 100 or 150 extra miles.

I recently forego the charging stations due to long wait and need to reach home 210 miles away but I didn't have 310 miles on the battery gauge.

I had 274 on the gauge so I drove at 55mph. I kept checking the gauge and the home distance making sure I have 50 miles extra.

With that speed, it did the trick and I had extra 70 miles on the gauge when I was about 30 miles from home (100 on the gauge - 30 = 70 extra.

That's when I increased my speed to 70mph to spend the extra miles down.

I got home with 47 miles on the gauge and plugged in at home.
 
What’s your current efficiency and SoC ? You can multiply these two to get a sense of actual range you have. (It also depends on external factors such as headwind, temp, and elevation)

If you are on highway then get behind the truck. This should help in cd and driving at 50-55 mph should help you as well. Offcourse, turn off Heat-AC.
 
28mph is the max efficiency if you can turn off climate control. At least that is what Lucid told some You Tubers that did over 700 miles in a GT. Hence, 50 is better than 55.
 
But sometimes you just want to char the crap out of a good piece of beef, so you smack it as hard as you can and have yourself a smashed burger

Both are tasty, but the smashed burger leaves you less full, causing you to need to recharge sooner

The patience of the brisket keeps you going all day
 
But sometimes you just want to char the crap out of a good piece of beef, so you smack it as hard as you can and have yourself a smashed burger

Both are tasty, but the smashed burger leaves you less full, causing you to need to recharge sooner

The patience of the brisket keeps you going all day
It takes about 135,000 slaps to cook a chicken using a meat beater
 
does anyone disagree that 28mph will get you the best mileage? I was thinking 40-45 ...
 
I have been wondering about the impact of speed on range and efficiency. So the other evening on a long ride on route 95 in New England I was bored and engaged in an impromptu test of efficiency.

For about 100 miles driving my 2025 AGT, using highway assist, with 20" Michelin all-seasons, in 25 degree clear weather, with no significant incline and little traffic, every ten miles I switched between 70 mph and 80 mph.

The impact on efficiency was dramatic! At 80 mph I averaged about 2.3 kwh. At 70 mph my efficiency increased significantly and I averaged 3.8 kwh. I was shocked that 10 miles per hour increase had that much of an impact on my kwh. I tried to control every variable I could to focus on speed's impact. Is this conclusion consistent with others?

This really opened my eyes and when I am traveling long distance and range is a potential issue, I'll try to moderate my speed. Just as an aside, I have a heavy foot and love the acceleration of the AGT and I average 3.10 kwh on the almost 6,000 miles driven since I leased the car in September.

My next test is to see the impact that seat warmers and heat have on efficiency, collectively and individually.
 
Someone earlier on this thread suggested drafting behind an 18 wheeler to maximize efficiency. The problem with this approach is that if you do it long enough you will run a serious risk of a rock thrown into your windshield or into your paint job. So yes you will get better efficiency but maybe at significant cost.
 

The dependence of air resistance on velocity​

The force of air resistance clearly depends on the velocity of an object moving through the air:
the larger the speed, the larger the drag force.

F (air) = Kv^squared
( the difference between 70mph and 80mph is HUGE)
plotting this will give you a exponential graph, with higher velocity requiring hugely increasing amounts of power.

However, at low speeds,the air resistance grows linearly with velocity:

F(air) = Kv (plotting the difference between 28 mph and 50 mph is almost a straight line)

1738671259525.webp


You can drive an ICE car at max velocity and cut your gas mileage in half, or more. I got 8 mpg or 16 mpg in my SL600 V12. That's a 50% swing. All performance ICE cars are like this. Tell me your Lucid is not a performance car...
I don't remember seeing "range" debates on any of the ICE car enthusiast sites I used to visit. It's a meaningless discussion.

if you drive an EV at max velocity you will cut your efficiency in half, or more.


like people, the Lucid battery likes to be comfy...not too hot / not too cold. When it's very cold the electrons don't want to play. When it's hot electrons run away.

Your job today is to figure out which of these formulae more accurately fits the data from a simple experiment. Go out and drive your Air around and see if you care a wit about efficiency.
 

The dependence of air resistance on velocity​

The force of air resistance clearly depends on the velocity of an object moving through the air:
the larger the speed, the larger the drag force.

F (air) = Kv^squared
( the difference between 70mph and 80mph is HUGE)
plotting this will give you a exponential graph, with higher velocity requiring hugely increasing amounts of power.

However, at low speeds,the air resistance grows linearly with velocity:

F(air) = Kv (plotting the difference between 28 mph and 50 mph is almost a straight line)

View attachment 26463

You can drive an ICE car at max velocity and cut your gas mileage in half, or more. I got 8 mpg or 16 mpg in my SL600 V12. That's a 50% swing. All performance ICE cars are like this. Tell me your Lucid is not a performance car...
I don't remember seeing "range" debates on any of the ICE car enthusiast sites I used to visit. It's a meaningless discussion.

if you drive an EV at max velocity you will cut your efficiency in half, or more.


like people, the Lucid battery likes to be comfy...not too hot / not too cold. When it's very cold the electrons don't want to play. When it's hot electrons run away.

Your job today is to figure out which of these formulae more accurately fits the data from a simple experiment. Go out and drive your Air around and see if you care a wit about efficiency.

I believe EV drivers obsess about range and efficiency because EV charging stations aren’t plentiful yet. Nor are they readily available when you arrive, or all that reliable.

If EV charging stations were as ubiquitous and convenient as gas stations, we wouldn’t even be talking about this.
 
The impact on efficiency was dramatic! At 80 mph I averaged about 2.3 kwh. At 70 mph my efficiency increased significantly and I averaged 3.8 kwh. I was shocked that 10 miles per hour increase had that much of an impact on my kwh. I tried to control every variable I could to focus on speed's impact. Is this conclusion consistent with others?
I was under the impression is was more or less common knowledge that efficiency decreases exponentially with speed. That is to say, the different between 40 and 60 mph is not the same as the difference from 60 to 80, which is not the same as 80 to 100, etc.

Not only is the drag increasing with the square of the speed, but there are non-linear costs associated with drawing power from the batteries due to losses associated with higher currents. In other words, if you need to double the amount of power going to the motors, it's going to cost you more than double in terms of energy expenditure due to the increased losses. All of that to say, you have quite a few factors working against you as the speed increases.
 
I was under the impression is was more or less common knowledge that efficiency decreases exponentially with speed.
Same here.

common knowledge and common sense , but with alternative facts and an overweb connection = "My car doesn't get the 517 mile range advertised." --Nanook of the North.


1738685023140.webp


Wait 'til we tell them about pV= nRt: "Why is my TPMS lit up?"

"Before cars had TPMS tire pressures never went down in the cold."
1738686865016.webp
 
Back
Top