Car and Driver Test Drive at 75mph - 190 miles

[JupiterMoon]

Does anything also agree that the Bolt should have upgraded wheels and suspension options? Like the BMW i3 with 20 inch rim upgrades, Chevy should also give this car a bit more pizzaz as an option.

Not necessary.

The Bolt is already much better shod with 215/50R17 vs. the i3's 155/70R19 unless you're the person looking to ride around on bling wagon wheels.

Bigger rims, more weight. More expense. Less tire options. More rotational mass. Probably no perceived improved handling. No thanks.

The i3 looks great with 20 inch rim option and it doesn't look bling at all. It matches the vehicle well. Plus the weigh of those rims is perhaps lighter than a standard rim as they are far narrower. It also makes for a quicker vehicle in general due to the torque multiplier by virtue of the larger rim diameter given a constant rotational speed.

 

[michael]

[ It also makes for a quicker vehicle in general due to the torque multiplier by virtue of the larger rim diameter given a constant rotational speed.

Huh?? What are you saying???

 

[JupiterMoon]

[ It also makes for a quicker vehicle in general due to the torque multiplier by virtue of the larger rim diameter given a constant rotational speed.

Huh?? What are you saying???

Basic stuff here man what do you mean what am I saying?

 

[GetOffYourGas]

[ It also makes for a quicker vehicle in general due to the torque multiplier by virtue of the larger rim diameter given a constant rotational speed.

Huh?? What are you saying???

Basic stuff here man what do you mean what am I saying?

In Michael's defense, doesn't the larger rim just mean a lower profile tire, and thus the same total wheel diameter?

 

[JupiterMoon]

Huh?? What are you saying???

Basic stuff here man what do you mean what am I saying?

In Michael's defense, doesn't the larger rim just mean a lower profile tire, and thus the same total wheel diameter?

Two things happen with a larger rim: A) due to a larger diameter it puts down more torque on the pavement. B) larger rims mean more distance required to travel due to a larger circumference so it can slow the car down. The two are competing so it depends where that balance is. Too small you lose performance...too large you lose performance. It's a curve of sorts.

 

[GetOffYourGas]

Basic stuff here man what do you mean what am I saying?

In Michael's defense, doesn't the larger rim just mean a lower profile tire, and thus the same total wheel diameter?

Two things happen with a larger rim: A) due to a larger diameter it puts down more torque on the pavement. B) larger rims mean more distance required to travel due to a larger circumference so it can slow the car down. The two are competing so it depends where that balance is. Too small you lose performance...too large you lose performance. It's a curve of sorts.

And all of these effects are too small for the typical driver to notice or care. It's only for those seeking to optimize to peak performance that even think about these things.

 

[SeanNelson]

Two things happen with a larger rim: A) due to a larger diameter it puts down more torque on the pavement. B) larger rims mean more distance required to travel due to a larger circumference so it can slow the car down. The two are competing so it depends where that balance is. Too small you lose performance...too large you lose performance. It's a curve of sorts.

The power and braking forces both have to be applied to the pavement, and that's done by the tire, not the rim. So it's really the tire diameter that matters, isn't it?

The rim size has an effect on the distribution of rotating mass. Assuming that the rim has a higher specific gravity than the tire, a smaller rim means the mass is concentrated closer to the axle, which means less overall angular momentum. That allows more of the torque delivered by the engine to be available for acceleration of the vehicle rather than the wheel and tire.

...or so it would seem to me.

 

[JupiterMoon]

Two things happen with a larger rim: A) due to a larger diameter it puts down more torque on the pavement. B) larger rims mean more distance required to travel due to a larger circumference so it can slow the car down. The two are competing so it depends where that balance is. Too small you lose performance...too large you lose performance. It's a curve of sorts.

The power and braking forces both have to be applied to the pavement, and that's done by the tire, not the rim. So it's really the tire diameter that matters, isn't it?

The rim size has an effect on the distribution of rotating mass. Assuming that the rim has a higher specific gravity than the tire, a smaller rim means the mass is concentrated closer to the axle, which means less overall angular momentum. That allows more of the torque delivered by the engine to be available for acceleration of the vehicle rather than the wheel and tire.

...or so it would seem to me.

Of course tire diameter matters but it's largely also dictated by how big the rims are. Usually a car that requires both a balance of straight-line performance and handling is limited to the tire it can use. You wouldn't use a large sidewalled tire for example on a car that requires such a balance for example. So then the rim becomes the main factor in the equation because it drives the tire size.

 

[JupiterMoon]

In Michael's defense, doesn't the larger rim just mean a lower profile tire, and thus the same total wheel diameter?

Two things happen with a larger rim: A) due to a larger diameter it puts down more torque on the pavement. B) larger rims mean more distance required to travel due to a larger circumference so it can slow the car down. The two are competing so it depends where that balance is. Too small you lose performance...too large you lose performance. It's a curve of sorts.

And all of these effects are too small for the typical driver to notice or care. It's only for those seeking to optimize to peak performance that even think about these things.

The average driver may not realize it but that's what differentiates the performance in cars that the average driver appreciates.

 

[GetOffYourGas]

No, I said that the typical driver wouldn't notice the difference, not that they wouldn't rewalize why. Heck, most drivers almost never actually demand full power from their cars.