Tesla Is Looking Into Ways to Lighten the Model 3

[TT97]

To be accurate... the claim he made was that there were welds and structural prices he didn't see the need for, which is not the same as meaning they can simply be eliminated now to save weight yet still meet Tesla's performance or safety goals. That's what I recall folks here generally objecting to.

The current initiative to lighten the vehicle likely means additional engineering exercise to do so safely, or eliminating weight in non safety critical areas, which may mean supplier involvement.

Munro's claims were the same as the current initiative. He had issues with Tesla trying to use multiple types of metals; adding unnecessary weight and making the production more complicated. While he never went into crash specifics, many on this site reacted as he was suggesting the entire car should be a single plastic mold.

Sandy Munro is a very accomplished engineer with decades of experience in automotive manufacturing. Sandy worked very closely and was mentored by an old professor of mine at NYU, Dr. Edward Deming. Although he was 90 when I took his class, Dr. Deming was an absolutely brilliant person and by far the most impressive professor I ever had. While Sandy's focus is on production and weight efficiencies, it is not done at a sacrifice of safety or performance yet many dismissed his ideas merely due to the fact that the bulk of his experience is not with EVs but with ICE vehicles (well that, plus aerospace, marine, defense, electronics, medical).

 

[DrDabbles]

Recently have side impact barriers, extensive crash protection,

It may seem counter-intuitive, but many of these advances can make a vehicle significantly lighter. The manufacturer can strengthen impact elements that surround critical cabin areas, and lighten components elsewhere while turning them into impact absorbing segments. A few heavy structural elements is a lighter solution than a vehicle with large, overbuilt elements.

rear view cameras, tire pressure monitoring devices,

We're talking ounces here, so not really an appreciable amount when compared to the overall vehicle.

Fuel economy standards for ICE vehicles,

This doesn't really relate to weight. I mean, maybe only in that a vehicle that has better fuel economy needs to lug around less fuel to achieve the same range. But this isn't a negative factor.

roll over protection, pedestrial impact protection,

Rollover protection can be accomplished in a lot of ways that add minimal weight to a vehicle. And honestly, adding structural protection for rollover crashes is a good thing.

multiple air bag systems, sturdy seat restraints,

Airbag systems have consistently been simplified and made lighter weight over time. Restraints being beefed up has a minimal impact on vehicle weight, and has a very direct impact on saving occupant lives.

break away rear view mirrors,

Doesn't add weight.

emergency item detection breaking systems

Adds minimal weight, since most of these EAB systems are all self-contained single board devices.

headlight requirements

Most of these have to do wight brighness, when the lights are on versus off, and the use of LEDs. Not really related to weight.

CHMSL lights

Those have been in place for decades, and it's a simple harness tied into the rear stop light wiring loom, and an LED. Again, not an appreciable amount of weight.

Vehicles keep getting heavier inspite of the manufacturers best efforts.

1990 Honda Accord EX: 21/27 MPG, 2923 lbs., 184.8 in. L x 67.9 in. W x 54.7 in. H -> 7.36 lbs / cu ft
2000 Honda Accord EX: 22/29 MPG, 3064 lbs., 188.8 in. L x 70.3 in. W x 56.9 in. H -> 7.01 lbs / cu ft
2010 Honda Accord EX: 22/31 MPG, 3302 lbs., 194.1 in. L x 72.7 in. W x 58.1 in. H -> 6.96 lbs / cu ft

What we're actually seeing is that vehicles are getting larger in every dimension, barely more efficient, but actually getting slightly lighter as a ratio of size to weight.

 

[Garlan Garner]

Munro's claims were the same as the current initiative. He had issues with Tesla trying to use multiple types of metals; adding unnecessary weight and making the production more complicated. While he never went into crash specifics, many on this site reacted as he was suggesting the entire car should be a single plastic mold.

Sandy Munro is a very accomplished engineer with decades of experience in automotive manufacturing. Sandy worked very closely and was mentored by an old professor of mine at NYU, Dr. Edward Deming. Although he was 90 when I took his class, Dr. Deming was an absolutely brilliant person and by far the most impressive professor I ever had. While Sandy's focus is on production and weight efficiencies, it is not done at a sacrifice of safety or performance yet many dismissed his ideas merely due to the fact that the bulk of his experience is not with EVs but with ICE vehicles (well that, plus aerospace, marine, defense, electronics, medical).

Murano did not do a great evaluation of the Model 3 concerning safety.

I wonder how much of the "Extra Metal" Murano complained about is there purely to make the Model 3 safer.

Something about the model 3 allows for Tons of articles saying this:

Model 3 achieves the lowest probability of injury of any vehicle ever tested by NHTSA
Tesla Model 3 gets perfect 5-star safety rating in every category from NHTSA [Videos]

 

[focher]

I would challenge anyone to crash into a 1970's Buick 225 electra….and then a 2019 honda civic. BTW...the one driving is driving a 1970's Cadillac Eldorado.

Which car would you like to be in that was hit?

Under almost any circumstance, your chances of survival and avoiding injury are better in the 2019 Honda Civic than the 1970s Buick. It’s not even really close. There’s a pretty obvious reason why auto related deaths have dropped over the years despite a significant increase in both drivers and driven miles. Cars today have much better safety designs.

 

[buckerine]

Under almost any circumstance, your chances of survival and avoiding injury are better in the 2019 Honda Civic than the 1970s Buick. It’s not even really close. There’s a pretty obvious reason why auto related deaths have dropped over the years despite a significant increase in both drivers and driven miles. Cars today have much better safety designs.

I don’t think he posed the right question. Let’s change the scenario to two 2019 Civics, both with the same safety features. Only difference is one just somehow has an extra 700 pounds of weight added. Now which one would you’d rather be in?

 

[animorph]

I don’t think he posed the right question. Let’s change the scenario to two 2019 Civics, both with the same safety features. Only difference is one just somehow has an extra 700 pounds of weight added. Now which one would you’d rather be in?

If those two cars are crashing into each other you want to be in the heavier one. Less deceleration than the lighter car. Providing the 700 pounds is not some exercise machine in the back seat ready to hit you if you stop suddenly.

 

[ItsNotAboutTheMoney]

I would have to disagree. I believe that if someone hit me with their car that I would be much safer in a heavy car than a light one …..on average.

I would challenge anyone to crash into a 1970's Buick 225 electra….and then a 2019 honda civic. BTW...the one driving is driving a 1970's Cadillac Eldorado.

Which car would you like to be in that was hit?


Me? I would choose to be in my 2018 Model 3 performance - just the way it is.

Tesla Model 3 crushes NHTSA's crash testing with a 5-star rating - Roadshow

You'll also get better visibility in traffic with a lifted pick-up. (Until everybody else buys a lifted pick-up.)

 

[phobos512]

If those two cars are crashing into each other you want to be in the heavier one. Less deceleration than the lighter car. Providing the 700 pounds is not some exercise machine in the back seat ready to hit you if you stop suddenly.

The amount of deceleration (or really acceleration as acceleration is simply any change though we've generalized to positive being acceleration and negative being deceleration) is not a function of mass. The time it takes to decelerate is. So, they both accelerate in the same time. It's not the [crash] that gets you, it's the sudden stop at the end.

 

[phobos512]

The amount of deceleration (or really acceleration as acceleration is simply any change though we've generalized to positive being acceleration and negative being deceleration) is not a function of mass. The time it takes to decelerate is. So, they both accelerate in the same time. It's not the [crash] that gets you, it's the sudden stop at the end.

Same amount. In different time. Is there no edit post button on this forum? Jeez.

 

[Big Earl]

Same amount. In different time. Is there no edit post button on this forum? Jeez.

There is. You just need a certain number of posts to activate it.

 

[Evbwcaer]

I don't think you can conclude that lighter vehicles are safer period. It depends on what vehicle you are in, what you are hitting, or being hit by.

Overall, a lighter fleet is probably safer at a macro level. I assume the advantage is really large when you go to carbon reinforced plastic, for example, when you reduce weight and increase strength at the same time. There a secondary safety benefits like reduced emissions, shorter braking distance, better handling, probably others too.

 

[Snerruc]

That's exactly right. The "more weight is better in a crash" is, at best, a holdover from before cars were built with energy absorbing crash zones.

The other obvious benefit of less weight is faster deceleration, which for many if not most accidents means lower impact velocity.

On the other hand. When a 6000lb. Model X hits a 4000lb. Model3, the 3 backs up.

 

[scaesare]

The problem is, and what many here objected to (including myself) is that Munroe said such things, yet in the very same video admitted he simply didn't understand why a lot of things were done the way they were. For example he pointed out the upper control arm design with CFRP inlaid in to a metal stamping, and freely admitted he didn't understand the design. Nor the reason for the damper attached to it

So, if you admit you don't understand the reasoning behind something, it's a bit incongruous to then say it's "adding unnecessary weight and making the production more complicated". How does he know it's "unnecessary"?

You might want to watch that video again.... he sprinkles similar comments all throughout. Start at about 45 mins in or so for the example I mention above.

Munro's claims were the same as the current initiative. He had issues with Tesla trying to use multiple types of metals; adding unnecessary weight and making the production more complicated. While he never went into crash specifics, many on this site reacted as he was suggesting the entire car should be a single plastic mold.

Sandy Munro is a very accomplished engineer with decades of experience in automotive manufacturing. Sandy worked very closely and was mentored by an old professor of mine at NYU, Dr. Edward Deming. Although he was 90 when I took his class, Dr. Deming was an absolutely brilliant person and by far the most impressive professor I ever had. While Sandy's focus is on production and weight efficiencies, it is not done at a sacrifice of safety or performance yet many dismissed his ideas merely due to the fact that the bulk of his experience is not with EVs but with ICE vehicles (well that, plus aerospace, marine, defense, electronics, medical).

 

[timk225]

Munro is paid off by the big automakers to talk down Tesla. The big automakers know their designs are inferior. Seems obvious to me.

 

[SigNC]

Every crash is better off with less weight involved. Less kinetic energy, thus less damage.

It would be great if Tesla can shave off some weight of all models, not just the 3.

While technically true you usually don't have much control over the other vehicle's kinetic energy. So, it's better for your car to have 50lbs more of frame instead of relying on the battery pack like the 3 has currently.

 

[bxr140]

On the other hand. When a 6000lb. Model X hits a 4000lb. Model3, the 3 backs up.

I appreciate the attempt to distill vehicular accidents down to a simple equation. The good news is that [in some ways] it is that simple...it’s just that many folks here are using the wrong formula.

What matters is the total energy in the accident, which in all cases. More energy brought to the accident (and both vehicles bring energy) means more energy to dissipate in the accident. More energy to dissipate means worse decelerations, which of course is bad for the occupants of the vehicles. As a friendly reminder from basic physics, E = m*V*V. So, more mass = more energy. All else equal, you'd absolutely prefer to be in a model 3 hitting a model X rather than a model X hitting a model X.

Obviously, the other major element is how that energy gets dissipated, and yes of course there's a counterproductive trade space where it often takes mass to create an effective energy dissipation structure...but that shouldn't be conflated with "more mass is safer".

 

[Uncle Paul]

One of Elon's goals was to make their cars with safety as a priority.

They usually produce some of the most crash worthy vehicles on the planet.

Remember something about them being unable to roll over an X for one of their tests as well as them braking the testing equipment for roll over protection.

If this is the reason that their cars weight more than the absolute minimum, perhaps that extra structure is for the better.

 

[TT97]

One of Elon's goals was to make their cars with safety as a priority.

They usually produce some of the most crash worthy vehicles on the planet.

Remember something about them being unable to roll over an X for one of their tests as well as them braking the testing equipment for roll over protection.

If this is the reason that their cars weight more than the absolute minimum, perhaps that extra structure is for the better.

Rollover has very little to do with overall weight - I bet you can't rollover a credit card. It is all about center of gravity - with batteries down low, center of gravity on Teslas are much closer to the ground than ICE cars. If Tesla removes weight from the structure on the X, rollover will improve even more.

 

[angelman]

Under almost any circumstance, your chances of survival and avoiding injury are better in the 2019 Honda Civic than the 1970s Buick. It’s not even really close. There’s a pretty obvious reason why auto related deaths have dropped over the years despite a significant increase in both drivers and driven miles. Cars today have much better safety designs.

My previous daily driver for last 15 years has been a 1967 Buick Skylark convertible. Any time someone says something like "oh they don't make cars today as safe as they used to. This good Detroit steel is solid and better than anything today", I send them this video. Bigger does not mean better. Good design and technology will beat brawn and weight any day of the week.
I drove my Buick every day as if it were my last. I was certainly under no illusions that I was in any way safe. Maybe this is why I have never had an accident of any kind in 25 years of driving..

 

[ngogas]

If I can lose 10 lbs that would help. Lol