EcoModder.com

EcoModder.com (https://ecomodder.com/forum/)
-   Aerodynamics (https://ecomodder.com/forum/aerodynamics.html)
-   -   Heresy! Smooth Wheel Covers- Myth Busted!!! (https://ecomodder.com/forum/showthread.php/heresy-smooth-wheel-covers-myth-busted-38310.html)

COcyclist 04-19-2020 12:20 PM

Heresy! Smooth Wheel Covers- Myth Busted!!!
 
At least on the VW Golf

I have tried various forms of wheel covers for over 10 years on my diesel Golf 5 speed manual with no real improvement in highly mpg. I have had several entire tanks testing them where the mpg seems to go down. Wheel covers are one of the first mods many people try on this forum. There is a historical tradition of using Moon wheel covers on salt flats race cars and intuitively they “look” like they would work much better than the blender blade mess of most alloy rims. I recently purchased Julian Edgar’s book and he quotes several studies of airflow and drag on car wheels. These studies show that totally smooth wheel covers are not the lowest drag option in modern automobiles. This would fit with my personal experience and motivated me to do some further testing in an A-B-A or even A-B-A-C-D options. I will post my test data and observations in a following post.

COcyclist 04-19-2020 12:31 PM

This is the most aerodynamic option
 
https://i.imgur.com/2XOyDbX.jpg

The VW GTI alloy 9 spoke rim gave me the best mpg in 2 days of testing and previous extended road trips. The alloy rims alone were better than with flat coroplast wheel covers.

Edit- It turns out this statement may be slightly misleading. Read on

Chonk_Master 04-19-2020 12:58 PM

Which option worked best?

COcyclist 04-19-2020 01:06 PM

Quote:

Originally Posted by Chonk_Master (Post 621980)
Which option worked best?

The GTI alloy rims with summer tires. It turns out tire choice was more important than any wheel covering.

cowmeat 04-19-2020 04:47 PM

Quote:

It turns out tire choice was more important than any wheel covering
That's pretty much a given

When I put the mirrored moon discs on my Insight I already had excellent LRR Bridgestone Potenzas tires on it, I did it mostly for the look - the moon discs did make the car look way cooler and they got random strangers to stop and ask about it, which in turn got me talking to people about ecomodding

In reality they also got me to work even harder at hypermiling - the car looked like it should do better with them on it so I drove it better if that makes sense

redneck 04-19-2020 06:15 PM

.

I’m curious.

Did you use the same rim and tire combination with and without a flat covering ?

Because if you didn’t, the difference noticed could have been from the overall weight of the combination used. Not the wheel covering.

Lighter wheels make a BIG difference.

Lighter wheels and a good LRR tires will make a even BIGGER difference.



>

COcyclist 04-19-2020 08:24 PM

Quote:

Originally Posted by redneck (Post 621997)
I’m curious. Did you use the same rim and tire combination with and without a flat covering?

The short answer is Yes. I tried multiple combinations and the best of all were the alloy rims bare followed by the same tire and rim with a flat coroplast cover which was consistently worse.

More to come.

Edit- If this were a newspaper I would be printing a retraction. I posted the quick reply to the question above before looking at my notes. As I was entering the test data last night I realized that the coroplast wheel covers edged out the bare alloys by 1 mpg.

COcyclist 04-19-2020 10:50 PM

Test Data Day One
 
Kudos to anyone who decides to do A-B-A testing. To do it right takes time and ideal test conditions to get good results. This testing was done over 2 days. I chose a long straight road with very little traffic and open fields on both sides. The runs were almost 2 miles in each direction at about 62 mph or 100 kph. Day one the temperature was 44 degrees with a 7 mph wind from the west. The road goes east west. I averaged the east and west runs together. I used cruise control and left the car running while I added or removed wheel covers and used the same start and stop points for all runs. I used the ScanGuage set to current MPG and reset it at the start point with the car up to speed and cruise resumed.

My A runs were with factory steel rims and the factory wheel covers with worn snow tires. The B runs were the same wheel and tire combination but with the wheel covers off.

A1 east/west average mpg- 54.7
B1 east/west average mpg- 57.85 (this was just the black steel rims)
B2 east/west average mpg- 53.6
A2 east/west average mpg- 55.85

I averaged all the A runs and all the B runs and got 55 mpg and a few decimal points for both. There seemed to be more variation with changing wind perhaps, than the variation of wheel covers on or off. :mad:

Tahoe_Hybrid 04-19-2020 10:53 PM

Quote:

Originally Posted by COcyclist (Post 621981)
The GTI alloy rims with summer tires. It turns out tire choice was more important than any wheel covering.

I put Eco tires on the drive wheel my MPG shot up on the same highway route it went from 27 to 31.2 15.55% increase

20 pounds less of rotating mass on both tires total :eek:

COcyclist 04-20-2020 12:24 AM

Test Data Day Two
 
My Day One results were inconclusive so I decided to do another round of testing. Day 2 was 59 degrees with the wind averaging 7 mph but occasionally gusting to 10-15 mph (as per weather radio from the airport just north of the test road). I increased the speed for all runs to 65 mph to try to highlight aerodynamic differences.

A1 runs Day 2 east/west average mpg- 48.45
B1 runs Day 2 east/west average mpg- 48.6
A2 runs Day 2 east/west average mpg- 50.65

The testing was still somewhat inconclusive. The differences could have been from wind changes or other traffic on the road.

I went home and changed to my summer tires and rims. My summer tires are replacements of the stock Goodyears which are getting thin. They are mounted on VW Mk III GTI 9-spoke replica Minilite rims. I also have coroplast wheel covers held onto the spokes with zip ties. Again I left the car running while I removed or installed the wheel covers to keep the same cruise control setting for all these runs. The C runs are the naked alloy rims and the D runs have the smooth wheel covers on over them.

C1 runs east/west average mpg- 56.45
D1 runs east/west average mpg- 54.1 (coroplast covers on)
D2 runs east/west average mpg- 56.1
C2 runs east/west average mpg- 51.75

On my last run of the day my west bound data may have been corrupted. I encountered some slower traffic and had to brake before the end of the run. I got only 47 mpg for that leg. I averaged the C runs with the spinning alloy spokes open to the air and got 54.1 mpg. I averaged the D runs with smooth wheel covers and got 55.1 mpg. There is not a huge difference but the advantage goes to the alloy rims with the coroplast cover by 1 mpg. I have some thoughts on this but will update more tomorrow.

The biggest difference was the change from snow tires on steel rims, covered or not, to lighter rims and summer tires- almost 5 mpg or roughly a 10% improvement!

2000mc 04-20-2020 02:08 AM

https://ecomodder.com/forum/showthre...ard-28594.html
I tried a similar test on my Saturn, unfortunately everything on the car warming up more and more skewed my measurements. Looked like bare steel wheels did the worst for me, but smooth vs factory hubcaps were very similar to each other

JulianEdgar 04-20-2020 02:22 AM

Quote:

Originally Posted by COcyclist (Post 621977)
[...] I recently purchased Julian Edgar’s book and he quotes several studies of airflow and drag on car wheels. These studies show that totally smooth wheel covers are not the lowest drag option in modern automobiles. [...]

Yes, I was surprised with what the formal (SAE-level) research papers showed re full wheel covers. I think a key point is that the wheel drag cannot be looked at in isolation eg the Tesla paper that showed how ventilation airflow through the front wheels could benefit overall drag (despite the wheels themselves then having more drag). My gut feeling is that wheel designs should be asymmetric front/back.

Congrats on your testing.

(Incidentally, I have a video coming up on some recent Porsche results on wheel drag and brake cooling. My channel - https://www.youtube.com/channel/UCK9...mNB9XEmuiCjxcQ)

JRMichler 04-20-2020 08:51 AM

I also found no improvement with wheel covers: https://ecomodder.com/forum/showthre...yon-32761.html.

COcyclist 04-20-2020 11:48 AM

More thoughts
 
I realized last night as I was entering the test data that if you only look at the averages, my results show the covered rims give a slight improvement over the bare alloy rims. As I noted in that post my final run may have been impacted by heavier traffic. Also, those runs were later in the day when winds are typically higher, gusting and variable here in the high desert. This makes it harder to get good data. I have tried various forms of the wheel covers over 12 years of driving VW TDI and my tank mpg averages would always go down when I used them. My best mpg tanks all occurred on summer tires with the bare alloy rims. I was puzzled by this so I assumed my wheel covers were somehow deflecting and trapping oncoming air. I doubled up on the wire ties. No improvement. My first attempt was larger, matching the widest part of the tire, so I tried a smaller set. No improvement. I assumed the ties through the spokes were too close to the center so I moved them closer to the circumference. No improvement. I purchased Julian Edgar’s new book- Modifying the Aerodynamics of Your Road Car, and found some information that could explain why I was not seeing positive results from this widely accepted modification.

California98Civic 04-20-2020 01:48 PM

I don't think it is heresy. The point about smooth discs has been published professionally. In the wheel discs showcase thread I posted a citation to a great informative essay (with pictures!). In short, smooth is very good but not the best. Here is the link: https://ecomodder.com/forum/showthre...tml#post603176

Frank Lee 04-20-2020 05:23 PM

Quote:

Originally Posted by COcyclist (Post 622017)
Kudos to anyone who decides to do A-B-A testing. To do it right takes time and ideal test conditions to get good results. <> There seemed to be more variation with changing wind perhaps, than the variation of wheel covers on or off. :mad:

Back in another epoch I did a college paper on aerodynamic devices and road-tested the standard fare: air dam, skirts, shovel-nose grille block, mirror deletes, etc. As much as I wanted my devices to create earth-shattering improvements to be honest they didn't rise above the signal-to-noise ratio of on-road testing and I had to admit as much in the paper. One reason I'm loathe to make mpg claims for mods is I know first-hand how hard it is to get good trustworthy data.

MeteorGray 04-21-2020 06:50 AM

I don't see how data can be trusted unless the effects of wind can be controlled (amongst other things, of course.)

So, testing in variable winds is a deal killer, for me.

aerohead 04-22-2020 10:59 AM

busted
 
Quote:

Originally Posted by COcyclist (Post 621977)
https://imgur.com/gallery/c3AbTZQ


At least on the VW Golf


https://imgur.com/gallery/7sVGG7k


I have tried various forms of wheel covers for over 10 years on my diesel Golf 5 speed manual with no real improvement in highly mpg. I have had several entire tanks testing them where the mpg seems to go down. Wheel covers are one of the first mods many people try on this forum. There is a historical tradition of using Moon wheel covers on salt flats and intuitively they “look” like they would work much better than the blender blade mess of most alloy rims. I recently purchased Julian Edgar’s book and he quotes several studies of airflow and drag on car wheels. These studies show that totally smooth wheel covers are not the lowest drag option in modern automobiles. This would fit with my personal experience and motivated me to do some further testing in an A-B-A or even A-B-A-C-D options. I will post my test data and observations in a following post.

How does that conclusion square with counterfactual evidence achieved from direct wind tunnel measurement? Why is Julian authorized to overturn nearly a century of observations and measurements?
How many,out of the total population of 'modern' cars are represented in these remarkable findings?

aerohead 04-22-2020 11:07 AM

road trips
 
Quote:

Originally Posted by COcyclist (Post 621978)
https://i.imgur.com/2XOyDbX.jpg

The VW GTI alloy 9 spoke rim gave me the best mpg in 2 days of testing and previous extended road trips. The alloy rims alone were better than with flat coroplast wheel covers.

Edit- It turns out this statement may be slightly misleading. Read on

The likelihood of isolating the drag contribution of wheels on a road trip is highly dubious.The SAE would never say it's even possible.This would be something which could only be confirmed in a wind tunnel.And the same wind tunnel,if done on separate days of testing.

aerohead 04-22-2020 12:20 PM

smooth wheels
 
I went back to the:
Index of Phil Knox Aerodynamic Seminars & Mod-data lists,under, Mod-data Lists: #7.
General Motors investigators found that the John Shinella aero wheels (think MOON wheels) for the Pontiac Trans Am,returned 0.027 lower drag than the open,standard steel wheels,as measured at the Lockheed,Marietta,Georgia full-scale wind tunnel.

JulianEdgar 04-22-2020 01:03 PM

Quote:

Originally Posted by aerohead (Post 622203)
How does that conclusion square with counterfactual evidence achieved from direct wind tunnel measurement? Why is Julian authorized to overturn nearly a century of observations and measurements?

Um, because I went and looked at what the latest tech papers actually say about current cars, rather than just quoting outdated tests that were often performed in technologically simplistic wind tunnels? The Tesla paper, quoted in the book, was highly illuminating.

JulianEdgar 04-22-2020 01:25 PM

Quote:

Originally Posted by aerohead (Post 622210)
I went back to the:
Index of Phil Knox Aerodynamic Seminars & Mod-data lists,under, Mod-data Lists: #7.
General Motors investigators found that the John Shinella aero wheels (think MOON wheels) for the Pontiac Trans Am,returned 0.027 lower drag than the open,standard steel wheels,as measured at the Lockheed,Marietta,Georgia full-scale wind tunnel.

Historic data is always interesting, but quoting wind tunnel test results for wheel drag when (1) the wheels weren’t turning, and (2) the undercar airflow was completely different, is not likely to be helpful when discussing wheel drag on current cars.

California98Civic 04-22-2020 01:42 PM

I want to offer this study into the mix. Ventilation drag seems to be a closely-related issue.

Alexey Vdovin, "Investigation of Aerodynamic Resistance of Rotating Wheels on Passenger Cars," (Gothenburg, Sweden: Department of Applied Mechanics, CHALMERS UNIVERSITY OF TECHNOLOGY, 2013).
http://publications.lib.chalmers.se/...302/176302.pdf

See also:
http://publications.lib.chalmers.se/...ext/133661.pdf
"Blocking the crossflow through the rims result in increased static pressure in the front wheel house and thereby an increase in lift, whereas blocking the crossflow in the rear result in increased downforce due to an increased flow rate through the diffuser. It was however shown that the resulting flow around the rear wheel was highly dependent of the rim design in the front."

aerohead 04-22-2020 02:40 PM

turning wheels/undercar
 
Quote:

Originally Posted by JulianEdgar (Post 622214)
Historic data is always interesting, but quoting wind tunnel test results for wheel drag when (1) the wheels weren’t turning, and (2) the undercar airflow was completely different, is not likely to be helpful when discussing wheel drag on current cars.

General Motors explored moving-floor wind tunnels in the early 1950s,and reported that the variability of drag data,as a function of the moving wheels was statistically insignificant,and the difference could easily be compensated for during static wheel testing,deeming the extra trouble not worth the effort as far as cost/benefit/accuracy.
As to the underbody flow,I'm unsure where the disconnect would be,compared to contemporary facilities.They were suctioning the tunnel floor,to prevent boundary layer buildup,which appeared to be the sole concern.'Windage' effects of rotating tires to wheelhouse and underbody flow had been explored.

JulianEdgar 04-22-2020 06:12 PM

Quote:

Originally Posted by aerohead (Post 622222)
General Motors explored moving-floor wind tunnels in the early 1950s,and reported that the variability of drag data,as a function of the moving wheels was statistically insignificant,and the difference could easily be compensated for during static wheel testing,deeming the extra trouble not worth the effort as far as cost/benefit/accuracy.
As to the underbody flow,I'm unsure where the disconnect would be,compared to contemporary facilities.They were suctioning the tunnel floor,to prevent boundary layer buildup,which appeared to be the sole concern.'Windage' effects of rotating tires to wheelhouse and underbody flow had been explored.

I am sorry, but are you seriously suggesting that wind tunnel testing of wheel drag, performed on a 1982 car without its wheels turning, is somehow relevant to modern cars?

Wind tunnels now test cars with a moving floor and spinning wheels. They do this for good reasons. I think this is probably the major reason that the research results have changed so much over the last decade or so.

The airflow patterns under a rough underside car like a 1982 Trans Am Firebird would be completely different to any modern car. The latest tech papers show that car drag can be influenced by how the wheels and under-car airflow interact.

I also note that "Index of Phil Knox Aerodynamic Seminars & Mod-data lists,under, Mod-data Lists: #7", as far as I can see, largely references material from the 1960s. As I said, old info is always interesting, but to apply it to current cars, when in fact current tech papers disagree, is in my opinion, not wise.

JulianEdgar 04-22-2020 06:21 PM

For anyone who wants to read the latest research data on wheel drag for themselves, here are the relevant papers I referenced in my book:


Vdovin, A., “Investigation of Aerodynamic Resistance of Rotating Wheels on Passenger Cars” Chalmers University of Technology, Gothenburg, Sweden, 2013

Mayer, W. and Wiedemann, J., "The Influence of Rotating Wheels on Total Road Load," SAE Technical Paper 2007-01-1047, 2007

Landström, C., Walker, T., Christoffersen, L., and Löfdahl, L., "Influences of Different Front and Rear Wheel Designs on Aerodynamic Drag of a Sedan Type Passenger Car," SAE Technical Paper 2011-01-0165, 2011

D'Hooge, A., Palin, R., Johnson, S., Duncan, B. et al., "The Aerodynamic Development of the Tesla Model S - Part 2: Wheel Design Optimization," SAE Technical Paper 2012-01-0178, 2012

...and too late for this edition of my book, but relevant is:

Wolf, T., "The aerodynamic development of the new Porsche Cayenne", Journal Automotive Engineering, I-19, 2019

JulianEdgar 04-22-2020 06:33 PM

To make it clear, based on the research I have cited in the book, I am not saying that fully covered wheels are bad. What I am saying is that fully-covered wheels aren't always best.

Do full wheel covers always reduce drag (from my YouTube channel):

https://www.youtube.com/watch?v=pTunD32hO44

California98Civic 04-22-2020 06:38 PM

Quote:

Originally Posted by JulianEdgar (Post 622231)
...Vdovin, A., “Investigation of Aerodynamic Resistance of Rotating Wheels on Passenger Cars” Chalmers University of Technology, Gothenburg, Sweden, 2013
...

This is the same study that I cited in post 23 above. It supports the idea that a flat disc surface is excellent in reducing drag. It finds a small added benefit inone other design. A graphic from the piece:

https://ecomodder.com/forum/attachme...1&d=1531604758

JulianEdgar 04-22-2020 06:52 PM

1 Attachment(s)
Quote:

Originally Posted by California98Civic (Post 622235)
This is the same study that I cited in post 23 above. It supports the idea that a flat disc surface is excellent in reducing drag. It finds a small added benefit inone other design. A graphic from the piece:

https://ecomodder.com/forum/attachme...1&d=1531604758

That shows that the wheel with the "thick outer radius cover" is in fact better than a fully covered rim. (The thick outer radius cover wheel has openings in it.)

It's one of the reasons that I state in the book that one should not always assume that full wheel covers are best for drag.

https://i.postimg.cc/9fpztRwt/wheel-designs.png

California98Civic 04-22-2020 09:43 PM

1 Attachment(s)
Quote:

Originally Posted by JulianEdgar (Post 622238)
That shows that the wheel with the "thick outer radius cover" is in fact better than a fully covered rim.

Right, but it is a quite modest improvement from the solid cover and without a wind tunnel for testing, guys could be forgiven if they went with the rule of thumb and used a solid cover. I think a nuance is getting lost here. The smooth wheel covers are still REALLY GOOD compared to baseline. Although COCyclist may have found a design that seems by his (necessarily imprecise) testing to work better than a smooth disc, it seems highly unlikely to me that smooth discs are infact worse than baseline.

For what it is worth, COCyclist's rims are a little like the "thick radius" rims, but they are not the same. The openings are larger and longer, extending further out from the center. A maxim to remember: each car is different, YMMV, and be skeptical of how any test applies to your vehicle.

https://ecomodder.com/forum/attachme...1&d=1587605142

In my case I made rims I knew would not conform to the smooth cover standard, but I liked them better because they are lighter and don't scream HYPERMILER. If COCyclist is digging the OEM look and feels confident they give him good results, I don't think it is "heresy" (or a "myth" "busted")

JulianEdgar 04-22-2020 09:52 PM

Quote:

Originally Posted by California98Civic (Post 622252)
Right, but it is a quite modest improvement from the solid cover and without a wind tunnel for testing, guys could be forgiven if they went with the rule of thumb and used a solid cover. I think a nuance is getting lost here. The smooth wheel covers are still REALLY GOOD compared to baseline. Although COCyclist may have found a design that seems by his (necessarily imprecise) testing to work better than a smooth disc, it seems highly unlikely to me that smooth discs are infact worse than baseline.

For what it is worth, COCyclist's rims are a little like the "thick radius" rims, but they are not the same. The openings are larger and longer, extending further out from the center. A maxim to remember: each car is different, YMMV, and be skeptical of how any test applies to your vehicle.

https://ecomodder.com/forum/attachme...1&d=1587605142

In my case I made rims I knew would not conform to the smooth cover standard, but I liked them better because they are lighter and don't scream HYPERMILER. If COCyclist is digging the OEM look and feels confident they give him good results, I don't think it is "heresy" (or a "myth" "busted")

If you want a rule of thumb, better in fact not to go for complete covers. Saying otherwise simply goes against the evidence. And that does in fact seem to me to be a myth busted.

California98Civic 04-22-2020 10:18 PM

Quote:

Originally Posted by JulianEdgar (Post 622253)
If you want a rule of thumb, better in fact not to go for complete covers. Saying otherwise simply goes against the evidence. And that does in fact seem to me to be a myth busted.

Sure, we could go with a rule of thumb like that. But "the evidence" is considerably more nuanced than you are allowing for some reason. In this article, the conclusion was not presented as universal for all vehicles. The authors knew their findings were dependent a little on the vehicle. Their study tried to account for how ventillation drag and air flow drag interacted. All vehicles are different in that respect and use different methods to ventillate the wheel wells. Results will vary and we're not in a good position, with street cars and street testing conditions, to know precisely what works best. So, you go with a reasonable rule of thumb. A solid pan is still a good intervention. Personally, I have been thinking of ventilating my design in a way similar to this study, but I have too many unfinished projects! :turtle:

EDIT: however, the study we're discussing suggests that all designs (except thick radius) perform more poorly than smooth covers. A rule of thumb for the thick radius seems supported, but that is not quite what COCyclist made. A rule of thumb for anything other than smooth covers or thick radius would not find support in this study, it seems to me.

JulianEdgar 04-22-2020 10:24 PM

Quote:

Originally Posted by California98Civic (Post 622254)
Sure, we could go with a rule of thumb like that. But "the evidence" is considerably more nuanced than you are allowing for some reason.

My evidence isn't based on just this one paper. See my reference list above that I used when writing that section of the book. Those references showed that full wheel covers on road cars aren't necessarily the best for lowest drag.

You can nuance that any way you like, but that is radically different from the advice so widely given, including on this discussion group.

ASV 04-22-2020 11:12 PM

it seems to me like the smooth full cover is still the best
for one simple reason.

It's something anyone can do to almost any wheel
where as the thick outer rim is not a rim I have ever seen
even once.

California98Civic 04-22-2020 11:19 PM

1 Attachment(s)
Quote:

Originally Posted by ASV (Post 622257)
it seems to me like the smooth full cover is still the best
for one simple reason.

It's something anyone can do to almost any wheel
where as the thick outer rim is not a rim I have ever seen
even once.

Totally agree about relative difficulty. But the thick outter rim design could be mimicked for experimentation by modifying cheap plastic rim caps from a big box store.

Or use ones like this... if you blanked the outter portions of the rim and left the openings nearer the hum open, then you would have something to play with.

https://ecomodder.com/forum/attachme...1&d=1587611928

JulianEdgar 04-22-2020 11:32 PM

Quote:

Originally Posted by ASV (Post 622257)
it seems to me like the smooth full cover is still the best
for one simple reason.

It's something anyone can do to almost any wheel
where as the thick outer rim is not a rim I have ever seen
even once.

It doesn't have to be a 'thick outer rim'. Tesla low drag wheels:

https://electrek.co/wp-content/uploa...0-07-24-am.png

Honda Insight Gen 1 wheel:

https://www.hubcaphaven.com/mm5/grap...1/aly63821.jpg

JulianEdgar 04-22-2020 11:38 PM

Quote:

Originally Posted by California98Civic (Post 622254)

EDIT: however, the study we're discussing suggests that all designs (except thick radius) perform more poorly than smooth covers.

It's not what I am discussing! I am discussing the results of five papers, not just one. In fact I found the Tesla paper the most interesting.

D'Hooge, A., Palin, R., Johnson, S., Duncan, B. et al., "The Aerodynamic Development of the Tesla Model S - Part 2: Wheel Design Optimization," SAE Technical Paper 2012-01-0178, 2012

California98Civic 04-22-2020 11:50 PM

Quote:

Originally Posted by JulianEdgar (Post 622261)
It's not what I am discussing! I am discussing the results of five papers, not just one. In fact I found the Tesla paper the most interesting.

D'Hooge, A., Palin, R., Johnson, S., Duncan, B. et al., "The Aerodynamic Development of the Tesla Model S - Part 2: Wheel Design Optimization," SAE Technical Paper 2012-01-0178, 2012

Did they do comparisons with the smooth cover design? Have any of that data to share here? The comparison is important for this thread, seems to me.

JulianEdgar 04-22-2020 11:57 PM

Quote:

Originally Posted by California98Civic (Post 622262)
Did they do comparisons with the smooth cover design? Have any of that data to share here? The comparison is important for this thread, seems to me.

Yes of course they did comparisons with fully sealed wheels. Otherwise, how could I have drawn the conclusion shown in my book?

I think I'll leave this thread there - the evidence is available for those who wish to look.

California98Civic 04-23-2020 12:03 AM

Quote:

Originally Posted by JulianEdgar (Post 622263)
Yes of course they did comparisons with fully sealed wheels...

And they found better results than this? Because the Tesla wheel you posted looks a lot like the star wheel on this table, and that star wheel did not do as well as the full cover. A company like Tesla, or Honda for that matter, will partly make final design decisions on the basis of looks, not just function.

https://i.postimg.cc/9fpztRwt/wheel-designs.png

https://ecomodder.com/forum/attachme...1&d=1531604758

Tesla low drag wheels:

https://electrek.co/wp-content/uploa...0-07-24-am.png

Honda Insight Gen 1 wheel:

https://www.hubcaphaven.com/mm5/grap...1/aly63821.jpg


All times are GMT -4. The time now is 07:51 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com