pepsi4all

Is there a possibility someone can mimic the Tesla aero wheels, make it dual side carbon? It is proven to be Aero. What you think?

Elvo

TPL

With Tesla you will be AlSet

CliffordK

qwaalodge

Car wheels are not meant to be aero.

The wheel rims are also designed to work like finned heat sink + fan to help cool the brakes. Those things create a lot of drag.

CliffordK

Many of the EVs have a fairly flat outer wheel design. Not entire impregnable to air, but reducing the turbulence along the outside of the wheel.

Here is a Car and Driver test of Tesla's Model 3 wheel covers.

https://www.caranddriver.com/news/a3...ficiency-test/

Apparently a simple plastic cover over an ordinary aluminum wheel.

They found the plastic covers improved efficiency at highway speeds by about 3.4%. Not huge but it increased the range by about 10 miles which might mean the difference between getting home and calling the tow truck.

dedhed

Cool until you get a good crosswind

PeteHski

A complete flat disc is as aero as you can get. Like on a TT wheel for example. But obviously not good in a crosswind. The Tesla wheel cap is a compromise between styling, aero and brake cooling. Only the aero part is really relevant to a bicycle wheel, but a flat disc is even more aero. Maybe a "Tesla" style disc might be fractionally better in crosswinds. Traditional alloy car wheels are not very aero at all, which is what Tesla have addressed with their trim design. It's quite effective.

msu2001la

It's weird to me that Tesla is credited for this design, when aero wheels and covers have been used on EV's/hybrids for years.

Here's a 2000 Honda Insight:



2012 Hyundai Sonata hybrid:




Even Formula 1 is using aero wheel covers now:

70sSanO

Yes, cutting edge aero technology.



John

3alarmer 

.
...I'm waiting for Tesla to start selling a fully autonomous bicycle, with hazard sensing, automatic braking, and autopilot. I'm only along for the ride anyway.

PeteHski

Where is Tesla credited for inventing aero wheel cover design? They just applied it.

msu2001la

Sure...

PeteHski

I was referencing the first post. It would be weird to reference something else in this thread right?

Inventing something and applying it are not the same thing.

PeteHski

Since the Honda was mentioned above, covered rear wheel arches (which Honda didn't invent either) are also more aero than open ones. But the aesthetics don't go down too well with marketing, which is why you rarely see them.

CliffordK

I've wondered about that. Those covered wheel arches have been around for a long time. Certainly since the 1950's.

One thing that I've noticed with many modern cars is that the wheels have been moved to the outside of the fenders. So, it is a smooth transition from car body to wheel and back to car body. Thus, potentially negating the need for the covered wheel arches, while at the same time maximizing the width of the wheels and improving stability.

burnthesheep

*Mostly* a misconception about crosswind stability. 100% a disc is faster in a crosswind. In fact, in some crosswinds the gains of using a disc are pretty ridiculous good. The dominant stability factor for a TT bike in a cross wind is the front wheel depth. Not the back. The front wheel is connected to the steerer tube, the back isn't. The back is more like the rudder on a ship.

*Mostly*: even if the front is mostly to blame and you go shallower up front on windy days....if you're a moron and in a gale run a rear disc instead of a normal aero rim all bets are off.

I ride the 90mm/disc combo in training most every ride. The 60mm only comes out for the front if the wind will cause "ditch or oncoming" traffic situations.

As for the original poster, vehicle aero wheels are intended to both maintain the flow down the side of the car (that has panels) and also to induce an inward flow to brakes or other areas needing cooling. So, it's so apples and oranges that it isn't worth pursuing the thought further. Closest would be balancing how hot a TT helmet or aero road helmet is in summer against how aero you make it.

CliffordK

PeteHski

Rear wheel fairings have been commonly used in sports car racing for many years. Illegal in open-wheel formula like F1. I agree on the transition making it less of an issue on newer cars. Wheel discs are certainly gaining popularity now efficiency is becoming more and more important. They were always pretty prominent on Indy Cars where speed was far more critical than brake cooling.

Mojo31

Porsche has developed "aero" wheels for its electric Taycan. But, they don't work like a bike wheel would have to work since they are essentially only aero on the outside. There are also other features that help the aerodynamics of the cars in the area of the wheels:

Another feature is the aerodynamic rims. To limit their drag, Porsche created a rim that is more “covered” than a regular rim. Second, the profile of the spokes has been designed in such a way that the air nicely slides across the spokes, instead of being pushed away by more blunt spoke shapes.

Finally, Porsche also air deflectors in front of the wheels: these are small “ramps” that divert the air so it doesn’t hit the wheels directly (where it would create a large wake). These are present both at the front and rear wheels.

Tech: Porsche Taycan Aerodynamics Explained | Clean Fleet Report

Mojo31

ICE cars perhaps. EVs, not so much.

Most EVs use regenerative braking except in extreme circumstances. On the Taycan, the brake pads don't even touch the discs except in emergency braking for the most part. In normal driving, the electric motors typically drive and stop the cars. The brakes rarely get hot.

PeteHski

That's a bit of an exaggeration, but the brakes do get used somewhat less when pottering around town. Regen braking is not that powerful. It's not much different to engine braking in a manual car IME.

Mojo31

From: Why Porsche Gave the Taycan Enormous Brakes (roadandtrack.com):

Porsche engineers assume that drivers of the new Taycan electric sedan will accomplish around 90 percent of their braking via regen.

Rather than change its braking performance standards for the Taycan, Porsche solved the problem by fitting those enormous brake rotors and ten-piston calipers. It seems a little funny given that, in normal daily driving, those giant brakes might almost never be activated, thanks to the car's regen capabilities.

From:We Evaluate Porsche Taycan's Unique Regenerative Braking System (insideevs.com)

Porsche wanted to do two things when they were designing the Taycan's regenerative braking system.

First, they wanted to recuperate as much energy as possible, and they believe they achieved that goal. Porsche engineers have said that as much as 90% of the Taycan's braking will, on average, be achieved through regenerative braking. The Taycan is capable of generating up to 265 kW into the battery pack.

That's accomplished by adding the front motor's 175 kW regeneration capability, and the 90 kW recuperated by the rear motor. To put the Taycan's 265 kW regenerative braking potential into perspective, the Tesla Model 3 can generate a maximum of 77 kW, less than 1/3 of what the Taycan is capable of pumping back into the battery.


I'll limit my comments to the car that I drive daily. So, not an exaggeration as far as the Taycan is concerned.

PeteHski

Fair enough, but the Taycan's system is not typical of most EVs as your previous post suggested. For example I drive Teslas and the regen braking is software limited to about 50-60 kW and ramped in progressively. So you still use mainly friction brakes when stopping from higher speeds.

70sSanO

You would think that they could have incorporated something like this...



John