When will Tesla begin to reduce the weight of the car, substituting carbon for metal.

When will Tesla begin to reduce the weight of the car, substituting carbon for metal.

These cars are still in the same weight class as conventional gas powered units. F1 has shown the way. How much do all the metal parts weigh in each Tesla model. Carbon fiber composites or better yet fullerenes could dramatically reduce the weight, as well as increase driver protection, reduce corrosion and increase longevity, as well as dramatically improve the power/performance/range equation. What would a two passenger+3 bags of groceries 1500 pound Tesla look like or better yet what would it's specs look like?
I want to see a carbon fiber giga-factory. It's only expensive until you make a serious commitment to the technology.

Red Sage ca us | 15. januar 2015

The Tesla Model S P85D has a curb weight of 4,925 lbs. That includes an 85 kWh battery pack, which by some reports may well weigh as much as 1,500 lbs. A conventional car of its size would have a fuel tank of perhaps 20-25 gallons of gasoline, which when filled might weigh around ~170 lbs. Replace the battery pack with a power storage device the same weight as a typical gas tank, and all things being equal, the Tesla Model S P85D would weigh in at about 3,600 lbs. For the sake of comparison, the other cars in its price category typically have a curb weight in the 4,200-4,500 lbs range in base trim.

The aluminum chassis and body weight of the Tesla Model S weigh around ~400 lbs. They form a structure that when combined with the battery pack, a stressed member of the design, is incredibly rigid and structurally sound. As a result, the car is exceptional in passing safety testing for survivability and protection of occupants during a crash. Carbon fiber, used to a similar extent in a vehicle this size would neither reduce weight significantly nor improve crash test results, but would certainly increase the manufacturing time to build and inflate the purchase price to buy.

Dramsey | 15. januar 2015

Not to mention the price to repair.

Old-style steel chassis and to some extent even modern monocoque cars can be repaired even after heavy damage-- laser-guided frame-straightening machines can re-align a bent frame or body.

A glued-together CF body on a CF tub would be totaled in a similar situation. Even minor accidents become horrifyingly expensive to repair: it's not as if you can tap a dent out of a CF door skin.

But perhaps there are design elements that can mitigate this. With CF cars like the BMW i3 and Alfa Romeo 4C, we should have some real world data soon...

tarheeltesla | 15. januar 2015

Couldn't agree more. I own i3 and the carbon fiber is amazing.

rlwrw | 15. januar 2015

Carbon fiber repair is done in the aerospace and aviation industries on a daily basis.
Yes, it involves sanding out the damaged area(s),, applying new fiber patches, curing, more sanding, and is time consuming, but still doable.

DTsea | 15. januar 2015

Its very difficult to get a class A finish on a bonded repair. Airplanes dont require that.

EmperorTytus | 15. januar 2015

RS, if the body and chassis weigh ~400 lbs, the battery weighs ~1500 lbs, and total weight is 4,925 lbs, then where is the extra ~3,025 lbs?

Dramsey | 15. januar 2015

I'm pretty sure the body and chassis weigh a lot more than 400 pounds...

Red Sage ca us | 15. januar 2015

It is a bit more beefy for the 'D', but the rear wheel drive Model S WS reported as 400 lbs for frame, chassis, & body panels. Aluminum works. Better than 90% of those components is aluminum.

All the other stuff... From tires and wheels, to glass and paint, to carpet and seats... Weigh a lot. Then there are the cooling systems, electronic control systems, inverter, motor, and reduction gear, and several thousand other components that make for a complete car.

Every little bit counts. Hence, no extra cup holders, vanity lights, grab handles, map pockets, coat hooks...

Brian H | 15. januar 2015

The i3's actually CFRP, not solid CF. Don't know what repairs cost, or its flammability. Alcoa's aluminum MiniMill in-house in a Tesla factory is more interesting to me.

Brian H | 15. januar 2015

Err: Alcoa MicroMill. 40% more formable, 30% stronger, 1500X faster to produce rolled product. Mill is 1/4 the length of current mills.

siberslug | 18. januar 2015

I'm not sure this was mentioned or not but this new battery tech is the cheapest and best way.

carlgo2 | 18. januar 2015

Anyone remember an ad showing four lithesome bikini-girls carrying an aluminum Audi? This was a bare body only. There is not a lot of weight to lose there once you go aluminum.

Our shop worked on a Ferrari that was hand-formed steel that was then sprayed with lead which was then sanded to perfection by skilled craftsmen who are now probably dead from lead poisoning...

Might sound strange, but is there a cheaper way to make a small run of steel cars?

A lead sprayer is the most dangerous thing I have ever seen in my life.

Sin_Gas | 18. januar 2015

Since ZEV credits for cars with 300 mile range are worth big bucks to Tesla, and they are so close, I think you will see a concerted effort to get the EPA 5 cycle number over 300. If carbon can do that, some of the cost can be covered by the ZEV credit dollars. Tesla needs to keep some, else why do it. May be frunk lids, trunk lids, some non critical parts to save weight would help.

This along with low rolling resistance tires, video side mirrors, special wax, deployable splitters and or other aero devices and other low drag tricks will be evaluated.

Sin Gas

vgarbutt | 18. januar 2015

i was watching one of those 'how that made that supercar videos, and they used carbon fibre rims for it. That would take some serious weight off.

It might even be light enough to put wheel motors in the model 3.

Brian H | 19. januar 2015

CF costs lots, shatters into microblade slivers on impact, is damn near impossible to repair, and so on. BMW embeds theirs in plastic (CFRP) for all those reasons.

DTsea | 19. januar 2015

No brian h. Notjing is made out of carbon fiber without resin... except carbon-carbon for reentry vehicles. Carbon is just shorthand for CFRP.

Dwdnjck@ca | 19. januar 2015

Elon is learning a great deal about eliminating mass through the use of light weight alloys at Space Ex. I am sure that he will be able to make use of this knowledge in cars.....soon.

Brian H | 19. januar 2015

Not according to BMW and reports. Far cheaper, less brittle.

Timo | 20. januar 2015

CFRP stands for Carbon Fiber Reinforced Plastic. Difference between CF and CFRP is that plastic. CFRP is more plastic than carbon fiber much like steel reinforced concrete is more concrete than steel.

Anemometer | 20. januar 2015

CF is like fabric. You can't build a car from it as it would flop to the ground. It's laminated in sheets with strands going in different directions and then some goop (plastic, polymer or something else I can't remember) is injected or painted onto it. Depending on whether it's being moulded or hand formed. The later being the expensive version.

I haven't seen a video but I'm assuming BMW has productionised the fabrication so that sheets are laid in the correct orientation by a machine (or a human) before another machine injects plastic to finalise the moulding and curing process.

As they are now building over 100 i3s per day I can't see it being a manual process, especially at German labour rates!

DTsea | 20. januar 2015


Typical resin contents are 35 to 45% by weight.