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When you don’t want to go on the trip, that’s a good thing… ask me how I know?Play nice, kids. Don't make me turn this car around...

When you don’t want to go on the trip, that’s a good thing… ask me how I know?Play nice, kids. Don't make me turn this car around...
Daniel,This is not true. The overall circumstance of the tire is approx the same. A larger wheel is fitted with a tire with a shorter sidewall.
Larger wheels are much heavier and the extra rotational mass decreases efficiency.
Also, summer tires are designed to deliver better grip which means more friction with the road surface and less efficiency.
The 21s are just heavier in general as well, more inertia therefore eneergy used to move them.The circumference of the wheel has almost nothing to do with the reduced range of the 20" and 21" wheel vs. the 19" wheel. The tire circumference is about the same on all the wheels offered by Lucid (the smaller wheels have taller profile tires mounted to them resulting in about the same tire circumference on all three). The impactful differences have more to with wheel width and which tires are installed on each. The 20" and 21" wheels have higher rolling resistance summer tires. Also the 20" and 21" wheels have wider tires mounted to them which is detrimental to aerodynamics.
Agree, given the same radius of gyration the increased mass requires more torque to rotate the ‘disk’ I,E wheels, assuming the radius of gyration is the same distance from the center of rotation (axle). However it is likely the 21” inch wheel sans tire has more mass at a greater distance from the axle which is a squared function requiring disproportionately more torque to rotate and maintain rotational speed.The 21s are just heavier in general as well, more inertia therefore eneergy used to move them.
The 19s are all seasons, not winter tires. The AS tires have lower rolling resistance than both the summers and winters, as both of those are made with traction in mind.Daniel2022AT
Oops - not per Google:
“Summer tires have lower rolling resistance than winter tires, which can improve handling and efficiency while also reducing noise. However, summer tires are not designed for winter driving conditions and perform poorly on ice and snow.”
So per the above the rolling efficiency of 21” is better than rolling resistance of the 19” M/S option leaving the increased torque to turn the 21” option as about the only rational conclusion for the negative range impact.
Ok rephrased the question with same/ similar response:The 19s are all seasons, not winter tires. The AS tires have lower rolling resistance than both the summers and winters, as both of those are made with traction in mind.
You can't believe AI...Ok rephrased the question with same/ similar response:
“Summer tires typically have lower rolling resistance than all-season tires, which can improve fuel economy”
However, because of their soft rubber compound, they wear out faster (compared to all-season tires) and increased rolling resistance, making them less energy efficient.
These tire sets offer low rolling resistance all year long. Therefore, all season tires guarantee better fuel efficiency.
The decreased rolling resistance manages to minimize the vehicle's fuel consumption and CO2 emissions.
Wow, what a great pitch for All Season tires. That’s been my choice for all my vehicles as I’ve always lived in snow country (currently preferring Michelin CrossClimate 2 for my Subaru Ascent).You can't believe AI...
From America's Tire regarding summer tires:
Discount Tire | Tires and Wheels for Sale | Online & In-Person
www.discounttire.com
From Priority Tire regarding all season tires:
Wrong comparison. Summer tires compared to high efficiency all season tires.Daniel2022AT
Oops - not per Google:
“Summer tires have lower rolling resistance than winter tires, which can improve handling and efficiency while also reducing noise. However, summer tires are not designed for winter driving conditions and perform poorly on ice and snow.”
So per the above the rolling efficiency of 21” is better than rolling resistance of the 19” M/S option leaving the increased torque to turn the 21” option as about the only rational conclusion for the negative range impact.
While there is often a correlation between traction and rolling resistance, especially in wet conditions, they are not the same thing and the rolling resistance certainly does not come from the coefficient of frictionThe tires themselves have significantly different coefficients of friction which impacts efficiency. By definition, sports tires or summer tires have greater grip which means greater friction and less efficiency. I think that is about a 10% difference. Maybe half of that again comes from the mass and geometrical physics. I’m guessing a 15% overall difference in efficiency between the 19’s and 21’s.