50% of your EV energy consumption comes from wheels and tires

[j-c-c]

So, my calculus is rather simple, if wider tires stop me say 8'? quicker, that is a potential huge amount damage/injury/time/aggravation/liability/etc savings in an accident that no mileage gains can ever offset.

[CapriRacer]

Originally Posted by Phase

the tire size on the new 2023 prius LE is P195/60R17

what are your estimates in fuel economy improvement if dropping those down to 15 inch wheels?

The differences between make/models of tires is much larger than the difference in tire size within a given make/model. So no one can provide an estimate that doesn't have a huge amount of error.

[CapriRacer]

Originally Posted by j-c-c

So, my calculus is rather simple, if wider tires stop me say 8'? quicker, that is a potential huge amount damage/injury/time/aggravation/liability/etc savings in an accident that no mileage gains can ever offset.

Yeah, that's always the conundrum. There is a risk and a cost no matter what you choose.

[Isaac Zachary]

Ya, cars, especially EV's, are getting heavier and more aerodynamic to the point that it's closer to 50% the energy used up by tires, although, it's complicated.

Even with regenerative braking, you're also still losing some energy to braking, so that's something to keep in mind.

The speed also makes a huge difference, as we all already know. At 75mph your wind drag is going to be more than rolling resistance in a Tesla. At 25mph, your rolling resistance is going to be more. What you average out to will depend on how and where you drive.

That being said, better rolling resistance is better, whether you're going 25mph or 75mph or 3mph or 87.3mph.

However, I'm of the mindset that traction trumps rolling resistance. If they can invent a tire that does well on pavement, water, ice and snow and get great rolling resistance, then awesome! But if not, I'll take the best traction possible over any amount of good rolling resistance. Right now I'm rocking some General Altimax 365's, an all season, all weather tire that has excellent snow and ice traction.

I do have another set of studded snow tires, but depending on how well the Altimax 365's do this winter, I may get a set of dedicated summer tires on those rims instead for better pavement traction and keep the snow-capable tires on during the Colorado traction law period of the year (September 1 - May 31).

[freebeard]

Yeah, that's always the conundrum. There is a risk and a cost no matter what you choose.

When you weigh happenstance against certainty, beefing up the sway bars might tilt the balance.

[Piotrsko]

Tire for all seasons: might i suggest the contitrac plus AS at only $250.00 each

[j-c-c]

Originally Posted by freebeard

When you weigh happenstance against certainty, beefing up the sway bars might tilt the balance.

The way some drive, "happenstance" might be a bit of an understatement.

Not sure of your intended use of the word "balance" here, ie regarding the conflict of chance vs certainty discussion or the say F/R balance of the vehicle, because beefing up a sway seldom except in the most extreme cases of body roll does a sway bar increase overall traction of a vehicle and almost never in a braking/accident avoidance situation..

[aerohead]

I ran an energy balance for the Chevy BOLT:
1) @ 40-mph, R-R is approximately 3.595-horsepower road load, to 3.48-horsepower for aero.
2) @ 85-mph, which is a legal speed in Texas, on certain toll-roads, R-R is 7.63- horsepower, while aero is 33.39- horsepower.
---------------------------------------------------------------------------------------
The velocity-cubed power law for aero really rears it's ugly head at speed.
Which makes assigning a one-size-fits-all relationship between R-R & aero problematic.

[j-c-c]

And in accident-avoidance braking distance calculations, which tire size is a direct factor, speed is squared.

Also I believe it's worth noting, we can assume within normal ranges/surfaces wheel diameter has little effect on rolling resistance or power consumption at steady speeds, but it's mainly determined by frontal area, shape (motorcycle tire vs car), rubber compound, tread pattern, tire aspect, inflation, temperature, load, and road surface.

[freebeard]

Not sure of your intended use of the word "balance" here

Prolly a play on words. OTOH, some accidents are roll-overs.