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21 Inch "fan" Wheels different on the right and left side of the car?

I love the look of the 21 inch wheels but I'm wondering if design will cause more drag on the right side of the car where the shape appears like it will "push" air into the wheel. In the left side it appears like the wheel will "pull" air out. I'm no engineer but if there were a mirror image of the wheel, one for the right side and one for the left side, then the wheels would both "pull" air and the forces would balance out. Any engineers out there who can comment on my concern?

@Brian10 You may want to refer to a previous thread in these forums, the same concerns leading to a discussion regarding the design of the "turbine" rims... What is interesting to note, at the Tesla Factory Event, I was told by the Chief Engineer that they had address this problem by introducing a new set of rims, engineered specifically to reduce drag and improve aerodynamics, boosting the range of the 300 mile battery to 320 miles. I do not believe the design of these rims have been released to the "public" as of yet. Goggle: forums/upcoming-qa-cheif-designer-franz-von-holzhausen-submit-your-questions? page=3

Here is the direct link:
http://www.teslamotors.com/forum/forums/upcoming-qa-chief-designer-franz...

Look for the discussion between @Denis Vincent and @David70.

Tesla please just mirror the wheels for better looks.

The problem with mirrored wheels of course, is that you can't rotate the tires. Frankly, I don't think anyone would notice that they're not mirrored.

If they're radials, you're not going to swap left and right anyway.

Thanks Volker The concern does not lie in the look of the rim, but its possible ground affects, a turbine will draw air from one side to the other. Unless they were mirror imaged, at speed the vehicle would have a tendency to track to the left.....!? Nevertheless, after speaking with the Chief Engineer at Tesla, I was reassured that the new rim design they've come up with not only addresses this concern but significantly increases range by decreasing drag coefficience.

I'm guessing, but I think the rims we saw at the Tesla event are the new rims. If you look at the turbine rims on the alphas, notably the picture of the white alpha being lifted into the lofted building, the turbine rims have 9 blades. The rims at the event had 10 blades, and each blade looked a little wider (thicker?) than the alpha turbine rims. Again, just a guess on my part. But then again most of what we say here is a guess....

DrJ;
But often very firm, opinionated guesses.
>;p

It is true that the white mockup and the first gray then red drivable prototype both had nine-blade rims, and all later pictures including Geneva Motor Show, March 2011, and "Alpha hits the road" had ten blades. Looking closer it turns out that even the ten-blade rims are *not* symmetric. All four wheels seem to be the same (I picked four random pictures from the Fremont Oct 1 event that seem to show the same beta car from different angles, assuming that images have not been mirrored before being posted to Flickr):
http://www.flickr.com/photos/12157123@N02/6209332767/
http://www.flickr.com/photos/12157123@N02/6209333265/
http://www.flickr.com/photos/stephenpace/6213649910/
http://www.flickr.com/photos/stephenpace/6213134509/

What does this tell us? Not much, actually. Either the final turbine wheels are not symmetric, or the rims shown on the betas are not the final version. Hm.

My guess is that they just made four identical wheels to see how they look, but didn't concern themselves with high speed effects caused by asymmetry. They just made the wheels and moved on till a newer executive decision was made.

What with all the discussion on this, they're probably thinking of putting innocuous but tantalizing details in the next photos to see what we make of them... If they have time for entertainment.

Volker.Berlin, thank you for directing me to that other thread. I don't see any "search" function in these forums so I had no way of knowing this thread existed. I apologize for reintroducing this old topic.

I apologize for reintroducing this old topic. (Brian10)

I think it's worth it, nothing to apologize for. I just thought you might be interested in reading the older comments on the topic.

I don't see any "search" function in these forums so I had no way of knowing this thread existed.

That's because there isn't any. You can use Google to search the public topics: Just add "site:www.teslamotors.com/forum/forums" (without the quotes) to your Google query.

Obviously, Google cannot find "private" topics (owners/reservation holders only), and not everybody on the web knows how to use Google to search the public ones. If you are an owner/reservation holder, you can comment to this thread to complain to Tesla about the lacking functionality:
http://www.teslamotors.com/forum/forums/tesla-we-need-search-google-does...

VB;
that thread should be retitled, "Tesla we mushrooms need search ..."

>:)

Am I the only one who is worried that the 21 inch wheels are too heavy and make the tires to thin. My volvo has heavy 18 alloy wheels with runflat tires, and it has way too much unsprung weight and too little tire flex. Basicaly because the tires are shorter, they have to be stiffer, probably not as stiff as the runflats, but it is the equivelent of removing a shock absorber, so the shock absorbers have to be softer. Because the wheels are heavier there is more unsprung mass, and because acceleration = force (of the shock absorber) / the mass (of the wheels) it takes the suspension alot longer to return the wheels to the ground.
In addition on rough pavement, soft high profile tires conform to the shape of the pavement, they will flex to grip the bump or fill in the hole, where as the stiff low profile tires behave as a sphere which will only touch a speed bump along single horizontal line, or touch the edges of a pothole along two horizontal lines.

Yup, the 21" wheels will make for a rougher ride. It's a given.

I hope that you do not have to get the 21 inch wheels with the sports pack, because I would rather have the 19 inch wheels with tires that I would source my self.(i.e. the ones on the Aston Martin V12 vantage)

We're pretty sure that some things will be required for the performance package. Among them are the 300 mile battery pack and the air suspension. It's unknown if the 21" wheels will be required.

Hopefully by the end of the year all of our option questions will be cleared up.

I think I just solved this mystery... At least to my own satisfaction. I was at my desk this morning where I have the plastic car they gave away at the October 1 event, and I started to wonder...

In the model, the turbine wheels are 10 spoke and indeed mirror matched left to right.

If it was important enough for the model maker to replicate, I think we can assume it's important enough for the finished car.

And if not, we'll have 50% better aerodynamics in reverse.

In the model, the turbine wheels are 10 spoke and indeed mirror matched left to right.

That's interesting news, thanks for sharing! Hard to say if any conclusions can be drawn from the model, but interesting anyway.

And if not, we'll have 50% better aerodynamics in reverse.

LOL!

Oog. You just gave me a vision of Reverse Gear Drag Races. Scary!

Well, it happened in Back To The Future #3 -.-

Re: aerodynamic wheels. Look at the 20-spoke turbine-design rims of the Audi e-tron spyder:
http://www.audi.com/com/brand/en/experience/design___technology/design_s...

I may be wrong but at first glance these seem to be very aerodynamic b/c they seem to have more of an almost even surface than actual spokes. Would be interesting to know if these are mirrored.

Well, they pull air inwards, in the photo version. Seem like about 30° angles.

@Brian H Same observation I made for at least 1\2 (until we find out otherwise) of the equation, which seems counter intuitive. From my limited understanding of ground effects and aerodynamics, I think you would want to create a vaccum underneath the undercarriage of the "skate board". As an investor in a company that provides 3\D rendering for the Aerospace and Defense Industry( Lockheed Martin JSF 35), AUDI (Etron) has designed a rim that takes full advantage of the Turbine capabilities for some purpose other than esthetics. It would really surprise me if the rims on the contralateral side were not mirror images of those or the right side, that clearly, (your observations and mine) would draw air underneath the chassis of the vehicle. There is no doubt in my mind that they were designed this way with some purpose in mind other than pure esthetics, which at speed would have a very significant affect on the performance and tracking of a vehicle, unless they were mirror imaged.

@Brian H After reveiwing the video clip of the Audi E-tron, there is no doubt that the rims on the right side are indeed mirror images of those on the left, drawing air in as previously observed. Tesla may want to draw inspiration from Audi on the design of E-tron's center stack and console, flawless!

Has anybody checked the real thing? The "video" on Audi's website is just a CGI for marketing purposes. I am hesitant to rely on what I see there, marketing may not even have talked to engineering about that and some summer intern may have thought the wheels look "better" with the blades to the wrong direction...

Denis;
So get an Audi. Different platform, different priorities, big driveshaft. That's a tiny $60-$80K concept car. Hybrid. Total interior space, about 5 cu'.
;-( :p

And the opposite side is mirrored. You can spin the image by clicking the U-shaped control at the bottom.

I think the look of the rim is just making the rims fancy. A car with 21 inch rims will run longer or easier than a 19 inch rim regardless how they look. I prefere Comfort thou, so I would like the "fan" rim in 19 inch.


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