To death the electric car ... and fast !!

[dede2002]

I just did the calculation in G

roughly the Model S Plaid accelerates to 1,35G between 0 and 100 km / h

it is 35% more than the acceleration of gravity

at € 130, you can "plead" your case, it is a useful car on a daily basis and not at all superfluous, very affordable.

The other one accelerates to 1.42g ... that means a tire-road adhesion coefficient greater than 142% ...? (gear effect or tearing of material)

Guess they didn't measure acceleration from 0 to 400 because the tires died before

With an 80 kWh battery the "full" autonomy would be about 3 minutes, enough to get your pan

[Ahmed]

I wonder if a confusion between "racing car" and "racing car" might not have crept into the discussion ...

[Christophe]

Hihi Ahmed!

The other one accelerates to 1.42g ... that means a tire-road adhesion coefficient greater than 142% ...? (gear effect or tearing of material)

Good point and I think it's even worse than 142% because there are 4 wheels ...

I have a little doubt ... it's far from my friction lessons ...

[dede2002]

... it's far from my friction lessons ...

Me too, in 1990 there were only certain motorcycles which exceeded 1g under braking, the teachers spoke of "gear effect".

For Nevera it might be April Fool's Day, since never means never ...

[Remundo]

The other one accelerates to 1.42g ... that means a tire-road adhesion coefficient greater than 142% ...? (gear effect or tearing of material)

here is a good remark

if we neglect aerosol friction and pneumatic drag, the propulsive force of the car is equal to F = mxa with m the mass and a acceleration.

However, in principle, a tire cannot pass more than T = f N to the road, with T the force tangent to the road and N the normal downforce.

It is considered that f is of the order of 0,8 for a road tire contact. and N = mxg with m the mass of the vehicle and g the acceleration of gravity.

we therefore have fmg = T = F = ma

So a = fg

Are we to believe that very specific tires were designed for this car, with an f coefficient above 1? As in F1 for example.

a tire which is hot and a little soft can have such a coefficient of friction, because on the fixed chippings of the bitumen, the rubber gets into the cavities and can create a small "gear effect".

On the other hand, it consumes a lot because the tire has internal energy losses due to these deformations which are not completely elastic. In addition, soft gums tend to wear out faster.

The performances announced by Tesla are of the order of that of a Formula 1 (around 1,3G).

racing car (without S), well seen Ahmed !

[Remundo]

on this link I found something funny
https://www.engineeringtoolbox.com/fric ... d_778.html

the coefficient of friction silver / silver dry need 1,4

quite Tesla's needs: silver wheel on silver road

[GuyGadeboisTheBack]

on this link I found something funny
https://www.engineeringtoolbox.com/fric ... d_778.html

the coefficient of friction silver / silver dry need 1,4

quite Tesla's needs: silver wheel on silver road

Copper: 1.6
Cheaper, anyway!

[Remundo]

yeah but there will not be enough copper to make the engine

[dede2002]

on this link I found something funny
https://www.engineeringtoolbox.com/fric ... d_778.html

the coefficient of friction silver / silver dry need 1,4

quite Tesla's needs: silver wheel on silver road

that is not even enough, it takes 1.42

The tire-road coefficient is 1 like back then, but they haven't filled in the second column, the slip coefficient, which makes all the difference between a tire and a silver wheel!

Other than that, I find this race for power stupid, but it works, around my home the Tesla are proliferating, I even have a customer who bought one .
Basically, when it accelerates fully, discreetly, it wears out the road as much as a truck and it is exempt from road tax.

That said, I have nothing against electric cars, I deplore the same phenomenon with thermal cars ...

ps: the formulas 1 they cheat a little with the aerodynamic supports

[Christophe]

I post this article on the reliability and certification of electric cars here: https://www.frandroid.com/produits-andr ... t-de-tesla

What the German technical control says about electric cars and more specifically about Tesla

You may have come across them... The famous German TÜV certifications, more commonly known as HU (Hauptuntersuchung), affixed to the license plates of sedans leaving the factories of the major German manufacturers. They have a very long history and a wide influence in the world. Exactly, there is enough data for first conclusions regarding electric cars.

It is the abbreviation of Technischer Überwachungsverein meaning in French: Technical Inspection Association. The TÜV are independent German companies whose objective is to ensure the validation and certification of products of all types to ensure their safety and protect the environment and (therefore) human health in the broadest sense, according to international standards. strict.

Regarding cars, the TÜV carry out a technical inventory of more than 150 essential operating points. The whole is summarized in 6 fundamental points: the braking/safety system, the steering, the suspension, the tyres, the lights, the windscreen wipers, the bodywork and the engine.

ENOUGH ELECTRIC CARS TESTED

At the TÜV, there were now enough electric cars for the first main inspection to carry out a "preliminary technical safety assessment" for at least four models: BMW i3, Renault Zoé, Smart Fortwo Electric Drive and Tesla Model S.

With the fewest problems and a defect rate of 3,5%, the Smart Fortwo Electric Drive model tops the stats. “In the list of 128 2-3 year old combustion engines listed in the TÜV report, the E-Smart would end up in the top third,” according to professional car inspectors.

The BMW i3 follows in second place with a value of 4,7%. In addition to the frequent faults of dipped headlights, there is a problem here that afflicts all electric cars: "Problems with braking components are typical of electric vehicles because they are used, compared to combustion engines, much less frequently and therefore corrode more frequently,” says association boss Joachim Bühler.

Incidentally, this is the main reason why, for example, Volkswagen uses drum brakes instead of disc brakes on the rear axles of the ID series.

With its Zoé, Renault has designed a model that would end up in the last third with an average of 5,7% defects compared to thermal cars. Defective and poorly adjusted headlights are among the small annoyances, but the TÜV also registers “above-average defects in the axle suspension“.

The Tesla Model S is far down in the rankings, with a defect rate of 10,7% – that means one in ten Teslas fail their first general inspection. Along with the deficiencies of the fog lights and dipped headlights, the triangle problems are the main problems.

On the other hand, these first results must be taken with a grain of salt. Indeed, the number of general inspections of electric cars is still negligible. These include 1142 inspections for the BMW i3, 1939 for the Renault Zoé, 1645 for the Smart Fortwo Electric Drive and 812 for the Tesla Model S (2013).