I currently have 225/65R17 tires on my car. I have noticed that many new electric cars come with larger wheel rim and lower profile tire, such as 235/45R21 tire. I wonder why -- after all, lower profile tires are less comfortable and have higher rolling resistance. Electric cars, if any, should avoid using low profile tires because range is such a critical parameter for them.
If we pick two rims and pair them with tires in such a manner that the rolling diameter stays the same, which is heavier:
- A traditional tire + wheel rim where the rim diameter in inches is small, or
- A low profile tire + wheel rim where the rim diameter in inches is large and the tire aspect ratio is modified accordingly to keep rolling diameter approximately the same?
The reason I'm interested is that it seems to be impossible to find any electric SUV with 17-inch wheels. Thus, I'll probably have to accept larger wheel rims (fortunately probably not 21" as 19" rims seem to be available in some limited cases). However, the 225/65R17 wheel+tire combo is already so heavyweight that my muscles ache for a day or two after seasonal wheel swap (where I live, I have to use dedicated winter tires during the winter).
Is the added aluminum lighter or heavier than the eliminated rubber in the low profile tires? (Let's consider only aluminum rims -- steel rims are outdated.)