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Discussion Starter #1
I hardly ever use my brakes and was thinking about adding wheel covers to improve efficiency. I know that some Leaf drivers do this and also the new Tesla comes with something similar. Would there be any negatives about blocking airflow to the brake system if you RARELY use them? Here is a link for what I am thinking of getting.

https://hubcapmike.com/17-inch-aluminum-racing-disc-wheel-covers/
 

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Not sure I want to drill/tap holes into my wheels. Plus, with the tires being run-flat with stiff sidewalls, the pressure for re-seating the bead is so high (nearing 100 psi according to the tech who re-seated mine). Many tire shops will not service "run-flats" since they do not have a "cage" for re-inflating these tires (near me, NTB & Sears won't). The risk to their employees is too great to assume. Drilling may be DIY but re-seating beads is NOT.
 

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in all honesty you'll get more range back by simply driving slower and working on better throttle control - attempting to optimize in this area is easily offset by driving habits, AC/Heater use, and external factors such as weather, traffic, and road conditions.

The aero wheels achieve a certain amount of range gain in controlled testing (such as EPA range ratings) but I doubt are a major factor in day to day driving.
 

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I would figure out a different way to attach the discs myself. The stock wheels have huge holes/gaps in them. It should be easy enough to secure the discs through those openings. I really want somebody to make aftermarket rear fender skirts for the Bolt!
 

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Not sure I want to drill/tap holes into my wheels. Plus, with the tires being run-flat with stiff sidewalls, the pressure for re-seating the bead is so high (nearing 100 psi according to the tech who re-seated mine). Many tire shops will not service "run-flats" since they do not have a "cage" for re-inflating these tires (near me, NTB & Sears won't). The risk to their employees is too great to assume. Drilling may be DIY but re-seating beads is NOT.
OK, I am confused. I would not call the Bolt tires 'run flats'....I thought those had a solid core or stiff sidewalls that could support load even at zero psi, rather than running on the rims.

I would call them 'self-sealing'....a conventional LRR tire with some goo.

In other words....I thought 'run flats' and 'self-sealing' were different things...are you saying the Bolt Michelins are **both**. Why would you do that?

As for the real world....I thought there were reports here of people getting 'flats'....i.e. a tire rupture that causes the car to load the rims and make the car undriveable....if so, this is a counterexample to the idea that the tires are 'run flats'. By their name....with run flat tires....you can still drive the car at zero psi in the tire, so long as it is still intact and on the rim.

https://www.edmunds.com/driving-tips/run-flat-tires-a-primer.html
 

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I also looked at Aeros. The clip on ones apparently always fly off eventually....probably decapitating someone in the process.

I think you get similar gains just by overinflation....as @bro1999 likes to demonstrate. I used that to great effect on my previous EV.

I have also seen people with steel wheels mod their wheel covers, e.g. by stretching t-shirt fabric over them to make a flattish surface, and maybe painting the result.

Maybe I'll try that when I get my snows/steelies put on.
 

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The only way I'd consider the hassle of aero covers is if their efficiency was demonstrated in controlled, instrumented testing. What little I know of aero comes from building race cars and IIRC, the gains go up with the square of the speed. It's doubtful at anything below highway cruise that aero wheels would show any gains in efficiency. Your opinions and results may vary, but facts are very helpful in discussions such as this. Anyone got any?

jack vines
 

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Aren't all design changes made to production cars, for aerodynamics, about improving highway performance? In low speed driving EVs already have a huge advantage over ICE.
 

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What little I know of aero comes from building race cars and IIRC, the gains go up with the square of the speed. It's doubtful at anything below highway cruise that aero wheels would show any gains in efficiency. Your opinions and results may vary, but facts are very helpful in discussions such as this. Anyone got any?
Yes goes up with the square and the cross sectional area. A friend and I did a back of the envelope and estimated that aero starts to impact the Bolt starting at 45. My rough experiments show that you don't really notice it until 55.

It's getting to the point however that you'll see more of what they did with the Bolt which is to say 'who cares? just put more battery in'. They dropped the aero wheel covers to keep the looks, and didn't taper the back too much to keep headroom, and instead stuffed it with the biggest battery they could (they also benefit from a highly efficient motor design due to power bar wound technology). Tesla is still chasing the aero obsession, I believe the 3 has wheel covers and they squeezed every fractional point of aero out they could. Not sure if it's because they believe in long road trips or just because.
 

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ProfessorBolta,

"I believe the 3 has wheel covers and they squeezed every fractional point of aero out they could. Not sure if it's because they believe in long road trips or just because."

I believe they went with the aero wheel covers, so they could get above 200 mile range on the base Model 3. I don't think they expect most of their owners to go with the small battery, or keep their aero wheel covers on. They just wanted to be able to advertise 200 miles of range for $35K.
 

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GJJETSON is right - the aero wheels were to hit a marketing "number" for the base model - I really don't consider them "useful" and real world driving tends to nullify the sort of efficiency gains from such tricks and beside people have declared them mostly ugly and simply removing the covers there are actually some nice wheels underneath…
 

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Discussion Starter #14
I hate those Now you Know people. There knowledge of science is about what my 8 year old daughter knows, they would make a shrine out of an Elon Musk toenail clipping, and their alternating playing stupid is annoying. Not many good EV channels out there.
 

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I hate those Now you Know people. There knowledge of science is about what my 8 year old daughter knows, they would make a shrine out of an Elon Musk toenail clipping, and their alternating playing stupid is annoying. Not many good EV channels out there.
Agreed. They’re definitely over the top with their Tesla worship. I’ve left a few comments on their videos, regarding their bashing of non-Tesla EVs. I do like that they do lots of quick segments, on different EV related topics. I’ll then go and find more info on the ones that interest me.

My favorite channel is Robert Llewelyn’s “fullychargedshow”. He’s entertaining and informative, and it seems like he does his research before reporting. Also, I was a huge Red Dwarf fan.
 

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My favorite channel is Robert Llewelyn’s “fullychargedshow”. He’s entertaining and informative, and it seems like he does his research before reporting. Also, I was a huge Red Dwarf fan.
I recently had a huge "D'oh!" moment when I finally that he didn't have all those Kryton figures on the shelf behind him just because he was a big fan...
 

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I was totally oblivious too, having watched a lot of Red Dwarf when I was younger! It was certainly one of those "ohhhh yeah!" moments!

As for the aero wheel covers, I'll probably pick up or build a set when I get my winter wheels and tires and do some split testing. Aero is the easiest way to gain a few points of efficiency on stock vehicles, I'm interested if there will be any measurable effect - cheap entertainment for data junkies!
 

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The spun aluminum covers do help, I believe there is realworld user testdata available on ecomodder. You can get IIRC 17" versions through mooneyes or maybe others too, but they are not cheap. Think theirs are hand made, not mass produced. Speedway sells them too.

The mounting method I've heard (1950's to present day dry lake guys do irrc) was to screw them in through the edge of the wheel in to the tire with self tapping screws. If the hole is between the bead and the wheel's edge you're ok, you don't want it towards the other side of the bead or it will leak air. There is actually a lot of material to work with on most wheels between the bead and the edge.

The other way they did it was to weld dzus tabs on to steel wheels then obviously use dzus fasteners. Pain in the ass, but functional and you get a look that you can't get any other way. If you're into that kind of look. Here is a mooneyes link:

https://www.mooneyesusa.com/MOON-Disc-s/211.htm

Ah dang I've watched all the Red Dwarf episodes. I didn't think anybody here watched that.
 
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