19" vs 21" Tires: Ride Quality/Range Difference

[ColoradoKent]

@hellowlucid,

I want to do the same. Will look for responses to Your post.

I also thought the 19" wheels looked ugly, especially since the plastic part required removal just to add air. I bought 20" HRE forged wheels as the Pirelli HL 20" tire OD is identical to the OEM 19" tires, hence the speedometer would not be off. I understand the wheels need to be forged because of the HP and weight, also the same for the EV style tires. I liked the look of the P204 HRE wheels but they are incredibly expensive. There must be others available that are cheaper. Also, when the new wheels were installed, the tire pressure sensors were kept in the same position to keep that system accurate. By the way, the people at HRE knew the exact Lucid wheel specs and the wheels fit perfectly and were about half the weight of the OEM wheels. They have even survived several curb kissings.

 

[Coho]

i'm thinking about swapping my 21" with a set of 19" before December. i have never swapped wheels on any of my cars before so complete newbie there. i don't really like the looks of OEM 19" wheels so i thought i'll look at some alternatives but most online stores i went to, don't even have any options for Lucid wheels (Costco tires, discount tires, tirerack) although they show options for tires. has anyone swapped their 21" wheels with non-OEM 19"?

If you look at the on-line Discount Tires website, they list a bunch of wheels for 19 in Lucid. Not sure if its accurate or not.

 

[AlanInMaine]

Not to worry, I can see where you're coming from with that assumption though!

EDIT: I should mention; handling characteristics definitely improve if the tire is wider, since there's more surface area gripping the road, but as far as I'm aware, the width of all the wheels is the same and it's just the diameter of the wheel that is different. As the wheel size increases, the sidewall of the tire decreases.

Also on the larger wheels and lower profile tires you get less sidewall flex for better handling.

 

[thecodingart]

No, I find the ride surprisingly compliant, especially compared to our Model S Plaid. I can't tell you how many passengers, including rear-seat occupants, have commented both on the quietness and smoothness of the ride, even though I almost always have the car in Swift or even Sprint mode, which slightly firm up the suspension. The ride reminds me very much of the Audi sedans I've had -- taut and well-controlled, but compliant. And the Audis had smaller diameter wheels.

I might be wary of the 21-inchers if I had to deal with potholes, but we don't see many of those in south Florida.

No we dont, but I am in central Florida and my rear passenger 21” popped. My warning for everyone is around the current reliability of the 21” Pirelli tires being used.

The upcoming 20” Michelins would be my strongest recommendation.

 

[DreamTour]

DE Rear Wheel is ~35 lbs. Not as light as i would have thought.

 

[hmp10]

DE Rear Wheel is ~35 lbs. Not as light as i would have thought.

Yes, that is heavy for a forged wheel. However, it's about the weight of the New Aero 21" aero forged wheel that was developed specifically for the Tesla Model S. I'm wondering if the high weight of these forged wheels has to do with the need to handle the weight of large EV sedans, which weigh hundreds of pounds more than ICE cars of similar size?

I believe the 21" Dream wheels are the only true forged wheel in the Lucid lineup, with the rest being pressure-cast (sometimes called forge casting to create marketing confusion). I wonder what the weight of the 21" GT rear wheel is?

 

[hellolucid]

If you look at the on-line Discount Tires website, they list a bunch of wheels for 19 in Lucid. Not sure if its accurate or not.

oh I must have picked the wrong filters then. You're right there's a bunch of them. Any idea which brands are reliable?

 

[DeaneG]

FWIW I noticed an HRE logo on the Sapphire's wheel in Ben Collins' video. Beautiful.

 

[Demosthenes]

My HRE P101sc's at 21 inch weighed in at 22lbs front, 23.4lbs rear versus my OEM GT 21's at 37.2lbs front and 38.2lbs rear. Huge difference but I'm told the GT wheels aren't forged. Still, I don't see how a forged monoblock from HRE can be 23 lbs but a forged DE or Tesla wheel still weighs in at 35+ lbs

 

[hmp10]

My HRE P101sc's at 21 inch weighed in at 22lbs front, 23.4lbs rear versus my OEM GT 21's at 37.2lbs front and 38.2lbs rear. Huge difference but I'm told the GT wheels aren't forged. Still, I don't see how a forged monoblock from HRE can be 23 lbs but a forged DE or Tesla wheel still weighs in at 35+ lbs

The New Aero wheel is an aerodynamic wheel with a large metal center disc to smooth airflow that probably contributes a lot to the weight. I'm less clear on where the weight is in the 21" Lucid Dream wheel, as it gets its aero characteristics from the plastic inserts.

All I can figure is that both wheels are overbuilt to create a larger load margin for carrying the weight of the cars, although I understand that the HRE wheels are load-rated for the Air.

 

[Demosthenes]

The New Aero wheel is an aerodynamic wheel with a large metal center disc to smooth airflow that probably contributes a lot to the weight. I'm less clear on where the weight is in the 21" Lucid Dream wheel, as it gets its aero characteristics from the plastic inserts.

All I can figure is that both wheels are overbuilt to create a larger load margin for carrying the weight of the cars, although I understand that the HRE wheels are load-rated for the Air.

Oh right, the metal center disc would probably do it. Got it! Interestingly, I haven’t noticed any range deficit with my very non-aero HRE’s and I’ve driven back and forth almost nonstop from San Diego CA to Vancouver Canada several times now

 

[hmp10]

Interestingly, I haven’t noticed any range deficit with my very non-aero HRE’s . . . .

I'm almost sorry to hear this, as now I've got to think about getting some. Those HRE's are beautiful.

 

[Neurio]

I contacted The New Aero a couple of months ago. Their wheels have about the same aerodynamics as the Lucid 21s, so there's nothing to gain in terms of efficiency. Shows you how well Lucid did in their design compared to Tesla.

 

[hellolucid]

There have been few attempts at swapping to non-oem at this point. Would be a great stickied topic for this forum, but you will need to account for the following:

-Bolt pattern (iirc, 5x120 on Air)
-Hub bore (this has yet to be confirmed online from my reading online, but can be overcome with hub rings)
-Diameter + width (would suggest keeping same as the factory 19" size)
-Tire size + load rating (would suggest keeping same as factory 19" size)
-Offset and brake caliper clearance
-TPMS sensors

You'd then need to have the TPMS programmed to the car and the tire size programmed. Lucid mobile service can do this. This sounds daunting but is far easier than one would imagine.
If anyone is enterprising enough to get the above information, I'd be happy to help vet out options, I've got lots of wheel / tire experience.

thanks for this list. any idea where i can find the load rating for lucid OEM?

 

[Sheena]

Probably covered before, but any difference in turning radius between tire sizes?

 

[DeaneG]

Probably covered before, but any difference in turning radius between tire sizes?

No, but turning radius is pretty good for such a large vehicle.

 

[Jeanwoodie]

A very interesting thread, but I have been unable to locate the real “elephant in the room”, which I believe is the rotational energy impacts of the two wheel sizes.

Out of spec Kyle thinks the 21”s look “cool”, so what does “cool” cost in terms of energy loss?
Per EPA approximately 10%. (4.2 miles/KWH vs 4.6 miles/KWH).

We know aerodynamic drag is a function of velocity squared, so perhaps the 21’s are a little less aerodynamic, but I think the ‘elephant’ is rotational energy.

We know that rotational energy is a function of rotational moment of inertia (linear) x rotational velocity (squared).

Rotational velocity is directly related to vehicle velocity and the same for both as they have the same OD.

Rotational moment of inertia is a function of both wheel diameter and wheel weight. The greater the wheel diameter the greater the moment of inertia; the greater the wheel weight (mass) the greater the moment of inertia.

There are some advantages of 21” over 19”, which mostly seem extreme performance, but mainly just “cool”.

 

[PhotoEye]

A very interesting thread, but I have been unable to locate the real “elephant in the room”, which I believe is the rotational energy impacts of the two wheel sizes.

Out of spec Kyle thinks the 21”s look “cool”, so what does “cool” cost in terms of energy loss?
Per EPA approximately 10%. (4.2 miles/KWH vs 4.6 miles/KWH).

We know aerodynamic drag is a function of velocity squared, so perhaps the 21’s are a little less aerodynamic, but I think the ‘elephant’ is rotational energy.

We know that rotational energy is a function of rotational moment of inertia (linear) x rotational velocity (squared).

Rotational velocity is directly related to vehicle velocity and the same for both as they have the same OD.

Rotational moment of inertia is a function of both wheel diameter and wheel weight. The greater the wheel diameter the greater the moment of inertia; the greater the wheel weight (mass) the greater the moment of inertia.

There are some advantages of 21” over 19”, which mostly seem extreme performance, but mainly just “cool”.

I'll take any formula that = "cool."

 

[Demosthenes]

A very interesting thread, but I have been unable to locate the real “elephant in the room”, which I believe is the rotational energy impacts of the two wheel sizes.

Out of spec Kyle thinks the 21”s look “cool”, so what does “cool” cost in terms of energy loss?
Per EPA approximately 10%. (4.2 miles/KWH vs 4.6 miles/KWH).

We know aerodynamic drag is a function of velocity squared, so perhaps the 21’s are a little less aerodynamic, but I think the ‘elephant’ is rotational energy.

We know that rotational energy is a function of rotational moment of inertia (linear) x rotational velocity (squared).

Rotational velocity is directly related to vehicle velocity and the same for both as they have the same OD.

Rotational moment of inertia is a function of both wheel diameter and wheel weight. The greater the wheel diameter the greater the moment of inertia; the greater the wheel weight (mass) the greater the moment of inertia.

There are some advantages of 21” over 19”, which mostly seem extreme performance, but mainly just “cool”.

If my wheel weight goes down 15lbs per wheel, and assuming all other parameters remain equal, what would be the impact on my miles/kWh?

 

[DeaneG]

For steady-speed freeway range, wheel weight makes little difference. Tire type (tread design, structure and compounds) and wheel aerodynamics can affect range up to about 10-15%.