20-ish mile range difference between 5 seat and 7 seat Gravity?

[037]

My all-time favorite tires were the Continental DW series and its successor, the DWS. I put them on our first Tesla, and they were superb in both dry and wet. Unfortunately, they eventually dropped the sizes for that car, and I started switching around. At one point I bought some Hankooks (don't remember the model) which weren't too far off the mark.

Continental has updated the DWS line with a "06 plus" but, sadly, it is not available in the sizes for any of the Gravity wheels. One of the staggered wheels will have a tire to fit, but the other wheel will not. If the Lucid wheel diameters weren't staggered, several more tire lines would fit.

I get staggering the tire widths, but I wonder what the reason was for staggering the wheel diameters?

DW went to the Super Sport line, DWS is all season. I really enjoyed the DW.

I am thinking they wanted to make the rear end more Sporty looking with thin tires and give front a bit more character with thicker tires and also give a little more cushion for the driver.

My 2c

 

[borski]

DWS06 were my favorite tires too.

 

[Elfin]

I get staggering the tire widths, but I wonder what the reason was for staggering the wheel diameters?

In the Out of Spec video they said they were told it was for looks. Staggered width is also silly in my opinion unless you're building a drag race car or have rear weight bias.

 

[hmp10]

In the Out of Spec video they said they were told it was for looks. Staggered width is also silly in my opinion unless you're building a drag race car or have rear weight bias.

I get the point of wider tires in the rear due to the rearward weight shift under acceleration. Given the torque the Airs and Gravity put down, this could keep traction control from intervening too quickly for spirited driving.

And with the Gravity having rear-wheel steering, they might have wanted a little more traction on the rear wheels when maneuvering under braking as weight shifts forward?

 

[BobFM]

With the range difference being ~50 miles for the 20/21 vs. the 21/22 in the 7 seat configuration, now it's got me rethinking about which to go with. Not an insignificant delta. That said, have heard mixed things about those Hankook tires in wet conditions...

 

[Knucklehead]

With the range difference being ~50 miles for the 20/21 vs. the 21/22 in the 7 seat configuration, now it's got me rethinking about which to go with. Not an insignificant delta. That said, have heard mixed things about those Hankook tires in wet conditions...

I have 10,000 miles on those same tires, and I like them. A lot. The handle water just fine, especially standing water on the highway. If you want to drive competitively, they are not for that. You will want to go with the P Zeros, or something that is even higher performance than those. Range, comfort and noise and the big benefits of the iONs.

 

[hmp10]

. . . have heard mixed things about those Hankook tires in wet conditions...

I have 10,000 miles on those same tires, and I like them. A lot. The handle water just fine, especially standing water on the highway.

There are a slew of reviews of this Hankook tire posted by individuals, and they seem to be fairly polarizing. Many people love them and actually compliment their wet handling. And many people find they come up short, especially in the wet. It's good that they might resist hydroplaning effectively, but that's not a proxy for handling lateral maneuvers, acceleration, and braking in the wet.

There's a summer performance version of the iON evo that one professional reviewer -- who gives actual objective measurements -- finds even better than the top notch Michelin Pilot Sports in everything but rolling resistance, including wet handling and braking. So Hankook has a handle on tire engineering. Unfortunately, he hasn't reviewed the all-season version that is on the Gravity.

Some of my favorite tire reviews come from TireRack with its detailed graphs, especially their spider graphs. Unfortunately, they show the Hankook as "not yet rated". However, they did write this summary narrative without making it clear how much testing they put it through:

That phrase about wet surfaces from TireRack gives me real pause. I'd really like to see some objective measures of the Hankook all-season's wet performance. Since I often drive in heavy rain during our long rainy season, I don't want a tire that I have to overly baby to keep a car under good control.

I'd really like to get comfortable with the Hankooks as an option I could consider for the Gravity, as I'm still a little taken aback by the range penalty that comes with the other tire/wheel options.

 

[hmp10]

Although TireRack says the Hankooks are "not yet rated", I found a video on their website that gives objective measurements for it. It was one of nine tires tested in an odd mix-up of summer-rated and all-season tires, some EV-specific and some not. The test included two of the tires on the Gravity: the Pirellis and the Hankooks. The test was done using a Tesla Model 3.

In terms of efficiency, the Hankook bested the pack at 263 watt hours / mile compared to the Pirelli's 274 watt hours / mile. This is a much smaller difference (4%) than the range difference of the two tires on the Gravity (12%), suggesting there's more at play than just the tires with the Gravity's range differences.

Among the nine tires tested, the Hankooks performed very poorly in wet conditions:

It was the worst in wet braking (104.6 feet vs. 95.3 for the Pirellis).

It was the second worst in wet corning (0.82g vs. 0.90 for the Pirellis).

It was the second worst in wet track times (31.91 seconds vs. 30.30 for the Pirellis).

There were some surprises in the test, with some of the all-season tires besting some of the high-performance summer tires in certain tests. Overall, though, the Pirellis were a very strong performer wet and dry (usually first or second), and the Hankooks were weak -- except in efficiency, where they easily took the prize. One of the wrap up comments on the Hankooks was that they were too quick to "step out abruptly" in too many situations.

This seems to support my suspicion that Lucid chose the Hankooks exclusively to get the highest EPA range rating it could while trading away handling dynamics.

Here is the link to the test. You have to click on the blue "Tire Rack Test" icon and then click on the video:

https://www.tirerack.com/tires/pirelli-p-zero-pz4

 

[borski]

Although TireRack says the Hankooks are "not yet rated", I found a video on their website that gives objective measurements for it. It was one of nine tires tested in an odd mix-up of summer-rated and all-season tires, some EV-specific and some not. The test included two of the tires on the Gravity: the Pirellis and the Hankooks. The test was done using a Tesla Model 3.

In terms of efficiency, the Hankook bested the pack at 263 watt hours / mile compared to the Pirelli's 274 watt hours / mile. This is a much smaller difference (4%) than the range difference of the two tires on the Gravity (12%), suggesting there's more at play than just the tires with the Gravity's range differences.

Among the nine tires tested, the Hankooks performed very poorly in wet conditions:

It was the worst in wet braking (104.6 feet vs. 95.3 for the Pirellis).

It was the second worst in wet corning (0.82g vs. 0.90 for the Pirellis).

It was the second worst in wet track times (31.91 seconds vs. 30.30 for the Pirellis).

There were some surprises in the test, with some of the all-season tires besting some of the high-performance summer tires in certain tests. Overall, though, the Pirellis were a very strong performer wet and dry (usually first or second), and the Hankooks were weak -- except in efficiency, where they easily took the prize. One of the wrap up comments on the Hankooks was that they were too quick to "step out abruptly" in too many situations.

This seems to support my suspicion that Lucid chose the Hankooks exclusively to get the highest EPA range rating it could while trading away handling dynamics.

Here is the link to the test. You have to click on the blue "Tire Rack Test" icon and then click on the video:

https://www.tirerack.com/tires/pirelli-p-zero-pz4

Keep in mind these were not the respective SUV tires. But otherwise seems valid; I’m not sure what changed for the SUV tires, if anything.

 

[hmp10]

Keep in mind these were not the respective SUV tires. But otherwise seems valid; I’m not sure what changed for the SUV tires, if anything.

I know, but this was the only comparison test I could find.

The Hankooks on the Tesla Model 3 and the Gravity both have sound absorbers, are EV-tuned, and have XL load ratings. As nearly as I can tell from pictures, the tread patterns are identical. However, the Gravity tire is designated 111Y (2403 pounds of load, 186 mph) and the Tesla tire 96W (1565 pounds go load, 168 mph). I don't know what, if any, difference that would make to handling characteristics. Also, I don't know what effect, if any, taking both tires up from Tesla sizing to Gravity sizing would have on the efficiency of each tire and whether the small 4% difference would be maintained.

 

[illopp00]

In the Out of Spec video they said they were told it was for looks. Staggered width is also silly in my opinion unless you're building a drag race car or have rear weight bias.

Yes but Gravity has rear power bias...same thing for handling and getting the off-the-line acceleration needs. But it's a trade-off for long term operating ease.

 

[Elfin]

Yes but Gravity has rear power bias...same thing for handling and getting the off-the-line acceleration needs. But it's a trade-off for long term operating ease.

For the SCCA EV-X class which has no tire size restrictions it looks the winning cars are running a square setup. Model 3's with 18" or 19" x 11" with 295 width tires seem to be the norm even though the Model 3 Performance also comes from the factory with staggered wheels. I'm sticking with my opinion that staggered wheels on AWD cars are silly.

 

[hmp10]

I like the look of the 20/21" wheels look pretty well and would seriously consider them if I could mount good high-performance summer tires. However, the only summer tire currently available for those staggered wheels is the Michelin Pilot Sport 4S.

The reason that I would choose that wheel is because I think its aerodynamics have a lot to do with the Hankooks providing so much more range on the Gravity (12%), as the efficiency measures from the Tire Rack testing show a much smaller efficiency advantage attributable just to the tires alone (4%).

Unfortunately, the Michelins were second from the bottom of the nine tires tested on efficiency (watt hours / mile). In fact, the Pirellis were closer to the Hankook efficiency number than to the Michelin number:

Hankook 263
Pirelli 274
Michelin 290.

All I can hope is the Pirelli will get around to sizing a tire for the smallest Gravity wheels before orders have to be confirmed.

If I'm right that the wheel aerodynamics have a lot to do with range on the Gravity*, and if the efficiency comparisons derived from testing on a Tesla Model 3 carry roughly over to the same percentage difference on the Gravity, then it might be possible to see something like 415-420 miles of EPA range with summer Pirellis mounted on the 20/21" wheels instead of the 386 miles for the 7-seat configuration.

* The fly in this analysis ointment is that the mid-size wheels on the Gravity also look to me to be more aero than the largest wheels, and the first are wearing all-season rubber and the second summer performance rubber . . . yet their EPA numbers are identical.

I have given myself a headache now. I hope anyone else who comes across this is fine.

 

[Elfin]

I like the look of the 20/21" wheels look pretty well and would seriously consider them if I could mount good high-performance summer tires. However, the only summer tire currently available for those staggered wheels is the Michelin Pilot Sport 4S.

The reason that I would choose that wheel is because I think its aerodynamics have a lot to do with the Hankooks providing so much more range on the Gravity (12%), as the efficiency measures from the Tire Rack testing show a much smaller efficiency advantage attributable just to the tires alone (4%).

Unfortunately, the Michelins were second from the bottom of the nine tires tested on efficiency (watt hours / mile). In fact, the Pirellis were closer to the Hankook efficiency number than to the Michelin number:

Hankook 263
Pirelli 274
Michelin 290.

All I can hope is the Pirelli will get around to sizing a tire for the smallest Gravity wheels before orders have to be confirmed.

If I'm right that the wheel aerodynamics have a lot to do with range on the Gravity*, and if the efficiency comparisons derived from testing on a Tesla Model 3 carry roughly over to the same percentage difference on the Gravity, then it might be possible to see something like 415-420 miles of EPA range with summer Pirellis mounted on the 20/21" wheels instead of the 386 miles for the 7-seat configuration.

* The fly in this analysis ointment is that the mid-size wheels on the Gravity also look to me to be more aero than the largest wheels, and the first are wearing all-season rubber and the second summer performance rubber . . . yet their EPA numbers are identical.

I have given myself a headache now. I hope anyone else who comes across this is fine.

Do you mean the Pilot Sport 4 SUV?
I've got the Pilot Sport 4S (265/40R18) on my Model 3 and they are amazing tires. Definitely took a 10% efficiency hit over narrower stock aero wheels with all-season tires.

 

[hmp10]

Do you mean the Pilot Sport 4 SUV?
I've got the Pilot Sport 4S (265/40R18) on my Model 3 and they are amazing tires. Definitely took a 10% efficiency hit over narrower stock aero wheels with all-season tires.

Yeah, these (from the Michelin website):

They've gotten great reviews since they've been on the market. (The non-SUV version was OE on our Model S Plaid.) But efficiency is not one of their strengths.

For some reason, though, Tire Rack does not list them among the four tires available for the Gravity 20/21" wheels. So I'm wondering if there is some reason why. They have plenty of load capacity. Maybe it's because the 265 width only has a "W" speed rating (168mph) instead of a "Y" (186)?

Has anyone seen where Lucid has set the Gravity speed limiter?

 

[Bill55]

Remember, the range difference has nothing to do with the size of the wheels. It has to do with the type of tires. If they have a larger contact patch or made of a stickier material, they create a little bit more resistance and therefore exact a range penalty.

Additional unsprung weight and slightly higher ride height both are impactful. The larger contact patch of course. The tire is multi compound with the center being similar across tires, at least that’s what Michelin says. Would be interesting to know exact percent of each item.

I would bet that either aero impact or weight is #1.

 

[Elfin]

For some reason, though, Tire Rack does not list them among the four tires available for the Gravity 20/21" wheels. So I'm wondering if there is some reason why. They have plenty of load capacity. Maybe it's because the 265 width only has a "W" speed rating (168mph) instead of a "Y" (186)?

Yeah, probably the speed rating. I've heard that many tire shops won't install tires unless they meet the OEM ratings for speed and load (and that's even if there are other OEM wheel diameters with lower speed and load!)
Yikes to the 20k mileage warranty (PS4S is 30k.)

 

[hmp10]

I would bet that either aero impact or weight is #1.

This one flummoxes me. I would bet on aero were it not for the fact that the mid-size wheels look more aero than the large-size wheels despite their identical range. Also, the larger wheels look to me to have less metal in the spokes than the mid-size wheels which might somewhat offset the aero effects with weight savings, at least in stop-and-go range testing.

I'm wondering if the largest wheels are forged, which would allow for the more open design in a vehicle that heavy. But, at least with the Air, Lucid specified which were the forged wheels (the Sapphire wheels and the 21" Dream Edition wheels), and they make no mention of forged wheels on the Gravity order configurator.

So the truth lies somewhere in the mix of (1) aero effects, (2) tire tread, compound, and sidewall construction, and (3) wheel and tire weights. We're probably never going to see testing of all the possible iterations or more detailed information from Lucid than we already have.

But the 51-mile range spread relating to wheels and tires seems extraordinary to me, especially since the Air Dream Performance only saw a 20-mile range spread between the 19" and 21" wheels (471 vs. 451 miles). I just can't quit trying to figure out if you can shrink that spread significantly with efficient summer tires on one of the smaller wheel options. I don't mind swapping tires on a new car, but I'd prefer to order the wheels I intend to keep.

 

[hydbob]

This one flummoxes me. I would bet on aero were it not for the fact that the mid-size wheels look more aero than the large-size wheels despite their identical range. Also, the larger wheels look to me to have less metal in the spokes than the mid-size wheels which might somewhat offset the aero effects with weight savings, at least in stop-and-go range testing.

I'm wondering if the largest wheels are forged, which would allow for the more open design in a vehicle that heavy. But, at least with the Air, Lucid specified which were the forged wheels (the Sapphire wheels and the 21" Dream Edition wheels), and they make no mention of forged wheels on the Gravity order configurator.

So the truth lies somewhere in the mix of (1) aero effects, (2) tire tread, compound, and sidewall construction, and (3) wheel and tire weights. We're probably never going to see testing of all the possible iterations or more detailed information from Lucid than we already have.

But the 51-mile range spread relating to wheels and tires seems extraordinary to me, especially since the Air Dream Performance only saw a 20-mile range spread between the 19" and 21" wheels (471 vs. 451 miles).

Worse aero, heavier car, seems like it lines up no? plus, just because it looks aero, doesn't mean it is aero =P LaFerrari has a CD of 0.3

 

[hmp10]

. . . just because it looks aero, doesn't mean it is aero . . . .

That could definitely be part of it. We don't have any actual figures, and probably won't get them.

However, I have to think there are aero benefits at least with the 20/21" wheels, as the Tire Rack tests suggest the efficiency differences between the Hankooks and the Pirellis can't alone account for the 12% spread in range we see in the Gravity between those two tire/wheel options.