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HuntingPudel

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Do you think aerodynamic drag or rotational weight is the bigger driver of range impact?
Back in the '80s and '90s we were putting wheel covers on wheels in race cars and/or skirts over the rears (TWR did skirts with the GTP Jags in the '90s, as did a bunch of the teams racing in European series in prototypes). That was for aero reasons. A more massive wheel/tire combo is going to increase fuel comsumption while accelerating. Once it's in steady-state motion mass makes no difference and aero is the reason for increased fuel comsumption.
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Do you think aerodynamic drag or rotational weight is the bigger driver of range impact?
It depends on the speed of the vehicle. At a constant highway speed of 75 mph, aerodynamic drag will have a much bigger impact on range. When speeding up to 25 mph and slowing down to 0, weight will most likely have a bigger impact.

EPA range includes a combination of different speeds, and I would love to see a study of the impact of wheel weight and aerodynamics on EPA range. My guess is wheel weight has an impact, but even at slower EPA test cycle speeds aerodynamics and ventilation resistance have a bigger impact.

Why do I think that? Because BEV cars tend to have heavier wheels that are more aerodynamic. I think the car companies have studied this a lot more than I have, and if weight mattered more than aerodynamics, they would put light but awesome looking wheels on the car. They don't. MME Premium wheels are average weight. Some Tesla wheels are actually very heavy.


21" Tesla Model S Turbine Wheel - Grey

2122-Turbine-Wheel-Grey.jpg


  • Size: 21X8.5"
  • Offset: +40
  • PCD: 5X120
  • Center Bore: 64.1mm
  • Weight: 21x8.5" = ~35.2 lbs (without tire), 21x9.0" = ~38 lbs (without tire)
 

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I can attest to the high quality of these wheels. The stock PP2 boat anchor wheels were the weak link of my car. A light set of forged wheels liberated it - here NES FG-08. Having some for the Mach-e GT could only enhance its performance and substantially decrease the work the motor(s) will have to do.

Ford Mustang Mach-E NES Forged Wheels by MRR Design | Light weight 6061-T6 Forged wheels IMG_1310


Ford Mustang Mach-E NES Forged Wheels by MRR Design | Light weight 6061-T6 Forged wheels IMG_5403
 

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Do you think aerodynamic drag or rotational weight is the bigger driver of range impact?
Depending on the weight reduction, the drag won't come anywhere close. Seeing how the drag won't actually act the way everyone thinks it will, it's really not that much (especially with the small differences in the coefficient of drag caused by the change in rim design). Rotational inertia plays a much bigger role. So, weight reduction is always going to be worth it. Now, changes in the width of the wheel is a different story, for a few reasons but I won't get into that.
 

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Back in the '80s and '90s we were putting wheel covers on wheels in race cars and/or skirts over the rears (TWR did skirts with the GTP Jags in the '90s, as did a bunch of the teams racing in European series in prototypes). That was for aero reasons. A more massive wheel/tire combo is going to increase fuel comsumption while accelerating. Once it's in steady-state motion mass makes no difference and aero is the reason for increased fuel comsumption.
Those were doing over 200 mph though... for typical use case of 70 - 80 mph max I'm not sure the extra weight of an aero wheel design or covers are going to be as beneficial as reduced rotating mass.
 


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Those were doing over 200 mph though... for typical use case of 70 - 80 mph max I'm not sure the extra weight of an aero wheel design or covers are going to be as beneficial as reduced rotating mass.
Depending on the weight reduction, the drag won't come anywhere close. Seeing how the drag won't actually act the way everyone thinks it will, it's really not that much (especially with the small differences in the coefficient of drag caused by the change in rim design). Rotational inertia plays a much bigger role. So, weight reduction is always going to be worth it. Now, changes in the width of the wheel is a different story, for a few reasons but I won't get into that.
@Mach-Tony and @EV Lab , do you have a study or data that can demonstrate that is true? I want it to be true, because I would like to put lighter wheels on my MME, but I don't think it is. If it were true, Tesla would put 23 lb wheels on on their cars. Instead, they put heavier but more aerodynamic wheels on them. Same for Ford, Audi, Porche, etc.

I have posted a study about this in other threads. The study does not evaluate the impact of wheel weight, however, so we are left to figure that one out alone. But obviously aerodynamic drag has a significant impact on BEV range.

Ford Mustang Mach-E NES Forged Wheels by MRR Design | Light weight 6061-T6 Forged wheels 1622380314465


According to the study, the wheels contribute around 25% of the drag on a car. That is significant. And at steady highway speeds, weight will have little to no impact. Weight has an impact when you are attempting to change speed, because it takes more energy to change the speed when the wheel is heavier - more energy needed to speed up and to to slow down. Of course when slowing down, a BEV can capture some of that energy needed to slow the car, offsetting the weight impact. How much is offset? I don't have a study about that, but it is similar to trying to determine the impact of a larger, heavier battery.

A larger battery adds range, but it also adds weight which reduces range. How much? Tesla knows. Ford knows. Same for wheels. A heavier wheel reduces range, but what if a heavier wheel is also more aerodynamic? Why does Tesla and Ford put a relatively heavy but more aerodynamic wheel on their cars? To reduce range, or increase range? If all they needed to do was make the wheel light, wouldn't they do that instead? It would be a lot easier than trying to make an aerodynamic wheel look good. Which, BTW, I think Ford did with the Premium MME wheel. It looks quite good. But not as good as the wheels that started this thread, of course. Which is why we are debating...

Here is a graph showing the impact of different wheel resistance forces. Unfortunately, they did not include weight, superficially mentioned rolling resistance, and focused on the impact wheel design has on aerodynamic and ventilation resistance (the resistance caused by the spinning wheel).

Ford Mustang Mach-E NES Forged Wheels by MRR Design | Light weight 6061-T6 Forged wheels 1622381555345


I think the data shows that wheel design has a significant impact on range, and a wheel with poor aerodynamics will reduce range at highway speeds. It would be great if someone could design an aftermarket rim that is light AND aerodynamic AND looks really good. Also, since the MME is so heavy, the rim needs to be much stronger than many light weight wheels are. It is a challenge, and I am disappointed no wheel manufacturers have tried to do it yet. That is what I am looking for if I am going to replace my wheels.

Here is the full text of the study:
https://publications.lib.chalmers.se/records/fulltext/176302/176302.pdf
 

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@Mach-Tony and @EV Lab , do you have a study or data that can demonstrate that is true? I want it to be true, because I would like to put lighter wheels on my MME, but I don't think it is. If it were true, Tesla would put 23 lb wheels on on their cars. Instead, they put heavier but more aerodynamic wheels on them. Same for Ford, Audi, Porche, etc.

I have posted a study about this in other threads. The study does not evaluate the impact of wheel weight, however, so we are left to figure that one out alone. But obviously aerodynamic drag has a significant impact on BEV range.

Ford Mustang Mach-E NES Forged Wheels by MRR Design | Light weight 6061-T6 Forged wheels 1622381555345


According to the study, the wheels contribute around 25% of the drag on a car. That is significant. And at steady highway speeds, weight will have little to no impact. Weight has an impact when you are attempting to change speed, because it takes more energy to change the speed when the wheel is heavier - more energy needed to speed up and to to slow down. Of course when slowing down, a BEV can capture some of that energy needed to slow the car, offsetting the weight impact. How much is offset? I don't have a study about that, but it is similar to trying to determine the impact of a larger, heavier battery.

A larger battery adds range, but it also adds weight which reduces range. How much? Tesla knows. Ford knows. Same for wheels. A heavier wheel reduces range, but what if a heavier wheel is also more aerodynamic? Why does Tesla and Ford put a relatively heavy but more aerodynamic wheel on their cars? To reduce range, or increase range? If all they needed to do was make the wheel light, wouldn't they do that instead? It would be a lot easier than trying to make an aerodynamic wheel look good. Which, BTW, I think Ford did with the Premium MME wheel. It looks quite good. But not as good as the wheels that started this thread, of course. Which is why we are debating...

Here is a graph showing the impact of different wheel resistance forces. Unfortunately, they did not include weight, superficially mentioned rolling resistance, and focused on the impact wheel design has on aerodynamic and ventilation resistance (the resistance caused by the spinning wheel).

Ford Mustang Mach-E NES Forged Wheels by MRR Design | Light weight 6061-T6 Forged wheels 1622381555345


I think the data shows that wheel design has a significant impact on range, and a wheel with poor aerodynamics will reduce range at highway speeds. It would be great if someone could design an aftermarket rim that is light AND aerodynamic AND looks really good. Also, since the MME is so heavy, the rim needs to be much stronger than many light weight wheels are. It is a challenge, and I am disappointed no wheel manufacturers have tried to do it yet. That is what I am looking for if I am going to replace my wheels.

Here is the full text of the study:
https://publications.lib.chalmers.se/records/fulltext/176302/176302.pdf
Tesla or any other manufacturer doesn't want to spend the money to put real forged wheels on their vehicles. Based on the calculations what they used in your article, it's a really simple equation to calculate the power needed overcome the additional rotational inertia caused by the weight. I feel like someone should have done this, but I could be wrong! I'll look it up.
 

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Those were doing over 200 mph though... for typical use case of 70 - 80 mph max I'm not sure the extra weight of an aero wheel design or covers are going to be as beneficial as reduced rotating mass.
On some of the road courses we aren't able to run much more than 135, and average speeds were in the 70s. At Martinsville Speedeay, NASCAR's fastest division runs average lap speeds in the mid 90s. Aero is effective everywhere. Highway speeds are generally steady-state which trivialize mass (Newton's first and second laws of motion in effect here). From an efficiency standpoint based on normal driving patterns, aero is orders of magnitude more important than rotating mass (unless you spend all of your driving doing quarter-mile accelration trials, but that's not the average, normal driving pattern). That doesn't mean that rotating mass isn't important in other aspects, only from the standpoint of fuel economy.
 

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I think two major factors not mentioned are: Braking cooling and rolling resistance.

BEV will have a wheel design which sacrifices brake cooling to get aero gains, because of regen reducing the brake cooling need. That's why you won't see the aero style wheels on anything "track package" related.

Rolling resistance drives the "skinny tire" choice.

I could only see weight reduction as a big deal if you are going for 0-60 times or track performance.
 

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On my Fiat 500e I replaced the stock wheels (14x5.5 front, 14x6.5 rear, 185-60-14) with Enkei PF01 15x8 wheels and sticky 205-50-15 tires. Each wheel/tire was ~8 - 12 lbs lighter. I saw ~2% reduction in range, which was most likely due the wider cross-section and sticky rubber. The car was transformed though... quicker, handled better and looked much better, with negligible impact to range.
 

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Tesla or any other manufacturer doesn't want to spend the money to put real forged wheels on their vehicles. Based on the calculations what they used in your article, it's a really simple equation to calculate the power needed overcome the additional rotational inertia caused by the weight. I feel like someone should have done this, but I could be wrong! I'll look it up.
Based on the data I have seen, if you don't exceed 20-30 mph, aerodynamics will have a negligible impact on range. So in that case, lighter wheels will have a positive impact even if they are less aerodynamic.

As @RonTCat mentioned, rolling resistance has a significant impact at all speeds (see the chart I posted). At slow speeds, rolling resistance will be more important than wheel weight, I think, because rolling resistance is constant whether accelerating, driving a steady speed, or decelerating. When decelerating, rolling resistance will steal the energy you would normally be able to capture with regenerative breaking, so even then it is a negative impact. Weight only significantly negatively impacts acceleration, because when decelerating you can capture much of that resistance to change with regenerative breaking. And of course at steady state speed weight makes no difference at all.

Ford Mustang Mach-E NES Forged Wheels by MRR Design | Light weight 6061-T6 Forged wheels 1622467163663


Rolling resistance is impacted by tire design primarily. If you get a fat tire, you can pump it up to 45 psi and mitigate the extra width. But you cannot mitigate the rubber composition or tread design. I have been searching for a low rolling resistance tire so that when I either put wider tires on the stock wheels, or get aftermarket wheels, maybe the lower rolling resistance of the rubber will offset the width.

There are two big problems with low rolling resistance tires: poor tread life and poor snow performance. If you read a tire review and they complain about those two items, it is probably because the tire is designed for better fuel economy. Not always, but that is what I am finding.
 
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mkhuffman

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Now back to my previous request: can an aftermarket wheel manufacturer please try to design wheels that mitigate aerodynamic and ventilation resistance? I am not concerned about city range in the MME, but I am concerned about highway range. And the data is clear: highway range will be significantly impacted by current aftermarket wheel designs. If you don't care about highway range, then great. Put these awesome looking wheels on your MME. I do care about highway range, so I won't be going down that route until there is an alternative that looks great and preserves my MME's highway range.
 

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Ford Mustang Mach-E NES Forged Wheels by MRR Design | Light weight 6061-T6 Forged wheels 1622467163663



To the Mach E family, simply put… We can’t wait to start building killer wheels for your Mach E projects, many of you have migrated from the Ford Mustang platforms and have a solid experience with the MRR brand, with this in mind rest assure we will be bringing in only the best of the best when it comes to high quality built forged wheels and customer service. No more boring paragraphs lets get this started with our NES Forged Collection.
Ford Mustang Mach-E NES Forged Wheels by MRR Design | Light weight 6061-T6 Forged wheels 1622467163663




All of our NES Forged wheels are custom built using 6061-T6 Forged Alloy Assuring a strong and light weight build, For the Mach E platform we are including light weight back pad pocketing which eliminates unnecessary aluminum by pocketing off certain areas in the spoke and back pad areas. Center bores are cut to hub centric profiles which means our center bores are to factory specs which will eliminate the need for hub rings and the risk of vibrations.

Ford Mustang Mach-E NES Forged Wheels by MRR Design | Light weight 6061-T6 Forged wheels 1622467163663


NES Forged wheels

  • Built using 6061-T6 Forged alloy
  • Hub centric centers
  • Light weight back pad pocketing
  • Can be built to accept oem center caps
  • Custom colors: solid tones, transparent colors, brushing and high polishing available
  • Concave profiles
  • Life time structure warranty
  • 3-year custom finish warranty
  • 7-8 weeks build time and delivery
Available sizes: 18x8.5-18x10.5, 19x8.5 -19x11, 20x8.5 – 20x12, 21x9, 21x12
Full Collection on this link
https://www.mrrwheels.com/collections/nes-forged

I will also post a few pics of finished orders to get everyone a true look at the NES Designs and colors.

For further information, Price info, questions simply comment and ill message you as soon as possible. You may also call our office directly at 323-887-8600



Carlos Morales

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do you have accurate weights for each style, size and width?
 
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do you have accurate weights for each style, size and width?
not for all styles and sizes as each wheel will be slightly diff in weight, we can only justify the actual weight from other sets we have built.
example a 19x8.5 45et weighs in at 21lb per wheel but a 19x8.520et will more likely weigh in at about 21.9lb each off set will change weight slightly as the major percentage of weight on a wheel is located in its center.
 
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