Performance not getting 310 miles promised

[Feathermerchan]

Actually lighter is always better. They don't add weight to race cars to make them faster.
Two big gripes for me are 35 series tires on the street is asking for trouble. And you have no spare.
Put a tape to the tire sidewall from the edge of the rim to the concrete. You'll see what I mean.
I have already bought a set of 18" tires and will but wheels soon. The sticky tires are real fun but they do rob range. Probably more than the wheels.

 

[darnelli]

I just picked up a performance 3 coming off a LR RWD getting about 250 Wh/mi (over a 100 mile total commute), and not driving at 65mph in the very early and very late return commute hours.

The P is pushing around 350 Wh/mi, only thing that I’m seeing to help solve this is new wheels and tires as well (only 18s that seem to fit the P are the tsportline turbines), and matching them up with the stock primacys from the aeros (since aero 18 wheels won’t fit).

Does this make sense to do or is there a more cost effective way to go about this?

 

[gilscales]

And the smaller your wheel the heavier your tire.

Yes, the 19" sport/tire combo and the 18" aero/tire combo are about the same weight.
The tires on the 18" are 3 lbs. more and the wheels on the 19" are 3 lbs. more (Approx.) One would think that with the weight more towards the center of the mass with the 19's they would be close in range but the range difference is mostly due to aero covers but also partly because the 18's are lower rolling resistance than the 19" tires.

 

[AlanSubie4Life]

Actually lighter is always better. They don't add weight to race cars to make them faster.
Two big gripes for me are 35 series tires on the street is asking for trouble. And you have no spare.
Put a tape to the tire sidewall from the edge of the rim to the concrete. You'll see what I mean.
I have already bought a set of 18" tires and will but wheels soon. The sticky tires are real fun but they do rob range. Probably more than the wheels.

I knew this would be the response!
This is a discussion about range. If you want handling and acceleration that is a different discussion. Definitely lighter is better in that context because you are changing directions/speed all the time! As I said, lighter is better (even for range), but it is definitely 2nd order and I doubt it will be noticeable on a 300-mile freeway run. Just doesn’t matter for range much (as you already said above!). We agree on that I think.

 

[NathanielHrnblwr]

I just picked up a performance 3 coming off a LR RWD getting about 250 Wh/mi (over a 100 mile total commute), and not driving at 65mph in the very early and very late return commute hours.

The P is pushing around 350 Wh/mi, only thing that I’m seeing to help solve this is new wheels and tires as well (only 18s that seem to fit the P are the tsportline turbines), and matching them up with the stock primacys from the aeros (since aero 18 wheels won’t fit).

Does this make sense to do or is there a more cost effective way to go about this?

Use chill mode and see if your numbers change. Getting 274 Wh/mi here.

 

[Dan_LA]

Smaller wheels with the same size tire will give a better ride quality for commuting, while larger wheels will reduce sidewall roll for performance and track usage.

opinion:
The 18's look too small, and 20's look best. I personally like the 19" option as they look better than 18's and are a nice in between. Light weight 19's would be nice.

Yea, and read some places, downsizing 2" might be too much as car is setup for 20" ... so 19" might be safe route, but then again, not sure is worth the headache for 7% improvement. Now if 18" is like 20%+ range improvement.. that's a lot... might be good idea to have one set for those longer trips... get someone that's trying to get rid of new 18". Just need to make sure I get good tires, not the Primacy ones (i think

 

[gilscales]

Aerodynamic wheels with lowest rolling resistance tires = most range but sacrifices some handling and some would argue the aesthetics as well.

 

[gilscales]

Yea, and read some places, downsizing 2" might be too much as car is setup for 20

Don't see how wheel size has anything to do with it, overall diameter of the tire is what the car is set up for

 

[AlanSubie4Life]

. Just need to make sure I get good tires, not the Primacy ones (i think

You are asking for the impossible here. Handling and LRR trade off with one another. There is probably an optimal tire which is a good mix of both, but that tire will not be the BEST for both. The Primacy is a great tire given how LRR it is. I am not aware (other than the Ecopia - but no data on a Tesla!) of a tire that does better for range. I would not be surprised if any other tire you pick is somewhat worse for range. The Primacy may in fact be the optimal tire - but it depends on the weighting function you use for your personal optimization preferences!

I think the best option is to stock multiple wheel/tire sets and swap out as appropriate. Then you almost always have the optimal solution for your current use. But this is not practical for everyone.

 

[Dan_LA]

I just picked up a performance 3 coming off a LR RWD getting about 250 Wh/mi (over a 100 mile total commute), and not driving at 65mph in the very early and very late return commute hours.

The P is pushing around 350 Wh/mi, only thing that I’m seeing to help solve this is new wheels and tires as well (only 18s that seem to fit the P are the tsportline turbines), and matching them up with the stock primacys from the aeros (since aero 18 wheels won’t fit).

Does this make sense to do or is there a more cost effective way to go about this?

Yep came to same conclusion but with different tires.. 18" TST with Pilot Super Sports (or the one offered by TST for All Weather Performance)... can't give up much handling, it's a 450HP vs previous 271 HP, the Primacy was extremely terrible on the 1st day rain in LA early Dec18. I think that's the best and most "cost" effective solution... And also what AlanSubie said up there, it would be a 2 set thing.. Although I doubt I would be swapping 20" back and forth... trying to find a better solution for range and keeping car handling as acceptable as possible. If not I will just live with 20" and maybe next tire change get a less tacky tire... Someone posted he could get 285 miles range (or was 285 Wh/mi) with 20" on warmer months and 5k driven... I am happy with that if that's doable.

There is also 20" TST forged option, we can reuse our tires I guess.

Aerodynamic wheels with lowest rolling resistance tires = most range but sacrifices some handling and some would argue the aesthetics as well.

Would you say more than wheels weight? Don't want to geek out on this (is it possible? ) at the end of the day I think it all adds up.

 

[gilscales]

Would you say more than wheels weight? Don't want to geek out on this (is it possible? ) at the end of the day I think it all adds up.

My best guess is aerodynamics of the wheel first then rolling resistance of the tires but for sure wheel weight last, AFAIK

 

[MXWing]

Smaller wheels with the same size tire will give a better ride quality for commuting, while larger wheels will reduce sidewall roll for performance and track usage.

opinion:
The 18's look too small, and 20's look best. I personally like the 19" option as they look better than 18's and are a nice in between. Light weight 19's would be nice.

I am digging those 19 inch Chinese Aeros.

 

[gilscales]

A somewhat technical and lengthy article written about EV aerodynamics covers wheels on pages 37- 39
http://publications.lib.chalmers.se/records/fulltext/250512/250512.pdf

 

[Glamisduner]

My best guess is aerodynamics of the wheel first then rolling resistance of the tires but for sure wheel weight last, AFAIK

Unsprung weight first, aerodynamics last would be my guess

 

[AlanSubie4Life]

My best guess is aerodynamics of the wheel first then rolling resistance of the tires but for sure wheel weight last, AFAIK

For range only (not handling) my guess based on Troy’s spreadsheet (though it is an inference on my part to some extent) is likely:

Tires > Aero > Wheel weight

What we can say for sure is the benefit of putting Aeros on the 18” will be a lot less if they are shod with PS4S rather than the stock Primacy. It’s just the way this stuff works, since the higher the overall losses the less aero matters. Less % impact on range. Another way to look at it: Energy saved with the reduced drag due to Aeros of course is the same in both cases, it just matters less.

 

[gilscales]

Unsprung weight first, aerodynamics last would be my guess

Only if start/stop and under 30mph is the goal after that aerodynamics rule, look at the Chalmers study I posted above in post #273

some graphs on pages 1 and 2 show where aerodynamic drag overcomes rolling resistance.

You can see that aerodynamics play the largest role in drag above 30 mph and the second graph shows where this drag is coming from with 45% on the top half of the car but an amazing figure to me is the wheel/wheel-well area accounting for a full 30% of the drag coefficient so now we see why the aero covers work so well.

 

[Glamisduner]

Only if start/stop and under 30mph is the goal after that aerodynamics rule, look at the Chalmers study I posted above in post #273

some graphs on pages 1 and 2 show where aerodynamic drag overcomes rolling resistance.

You can see that aerodynamics play the largest role in drag above 30 mph and the second graph shows where this drag is coming from with 45% on the top half of the car but an amazing figure to me is the wheel/wheel-well area accounting for a full 30% of the drag coefficient so now we see why the aero covers work so well.

Downloading now 45mb!, but isn't acceleration usually where all cars are the least efficient thus the biggest difference over all. Drag isn't the only factor? Rotating mass requires significantly more energy to get going than non rotating mass. The energy stored in rotating mass is lost in most cars when you use the brakes, maybe slightly better for ev's. But if you take 12 lbs peer wheel off that's something close to having an entire extra passenger in the car weight Wise. also there is more reported efficiency losses between 20" wheels and uncovered aero wheels than aero wheels with covers on/off.

 

[gilscales]

Downloading now 45mb!, but isn't acceleration usually where all cars are the least efficient thus the biggest difference over all. Drag isn't the only factor? Rotating mass requires significantly more energy to get going than non rotating mass. The energy stored in rotating mass is lost in most cars when you use the brakes, maybe slightly better for ev's. But if you take 12 lbs peer wheel off that's something close to having an entire extra passenger in the car weight Wise. also there is more reported efficiency losses between 20" wheels and uncovered aero wheels than aero wheels with covers on/off.

I remember reading about a guy who races his p100d on youtube, he gutted his interior until he got in the 10's I think but he then went to lighter wheels shaving several pounds of weight per corner with no effect on his quarter mile times.

Found the video

He does mention that even though the wheels are much lighter he put that weight back in with the heavier tires

 

[Glamisduner]

I remember reading about a guy who races his p100d on youtube, he gutted his interior until he got in the 10's I think but he then went to lighter wheels shaving several pounds of weight per corner with no effect on his quarter mile times.

Found the video

He does mention that even though the wheels are much lighter he put that weight back in with the heavier tires

Tire weight is worse than wheel weight due to the location of mass being father from the point of rotation.

 

[AlanSubie4Life]

Tire weight is worse than wheel weight due to the location of mass being father from the point of rotation.

Sure, but to first order it doesn’t matter if you’re talking about range. If you’re constantly speeding up and slowing down you’re never going to get the rated range anyway, so that particular case (where wheel/tire weight matters a little more) isn’t too relevant to the discussion.

The OP is concerned about how to get close to the rated 310-mile range. And for that my opinion is that it is tires first, aero second, then wheel weight.

Tires are a constant drag. Wheels, on the other hand (except for aero losses), once they are spinning, they’ll stay spinning basically forever (neglecting all other sources of drag which slow the wheels down - like the TIRES). That is why tires matter and weight does not (to FIRST ORDER). It’s the sources of drag that limit your range! Otherwise these cars would go forever!

And as I said earlier, it takes more energy to get the boat anchor wheels spinning, sure, but it is a small percentage of overall vehicle weight (which, YES, would matter on a racetrack/drag strip where every fraction of a second counts!), AND you get a large fraction of it back on regen. And this process (to FIRST ORDER) only happens one time on a long freeway run. (And yes, as mentioned earlier...the EPA numbers are a blend of highway and city driving...so yes, this is a first order effect argument...of course lighter wheels will help a tiny bit - just not as much as something that matters for every inch you travel - tire rolling resistance)