254 miles real-world range at 75 mph around freezing

[Kingske]

Question. What tire pressure do you have? Big impact on range? I have 20" snow tires, pressure about 42psi at 10c.

In my garage (about 12C) the front tire pressure is 40 psi and the back 38 psi. 19” wheels with all-season tires.

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[NC_Taycan]

On the tire pressure, don't go by the sticker in the door sill - that's for full load. In the PCM menus you can find the partial load pressure. Go somewhere in between full load and partial load (better traction at lower PSI, better range at higher PSI).

 

[Mike in CA]

@Kingske yes I agree

I moved from a Model X with 21” wheels (2016) to a (2017) with 19” wheels and range was dramatically improved

EV’s are sooo close to efficiency limits you can actually “see” the efficiency impacts, something much more difficult with gas cars.

Since the issue of larger versus smaller wheels and range has come up I'm curious about something.

There are several attributes of larger wheels that can have an effect on range and I've read that one of the major ones is weight. I haven't seen any discussion around this, but Is it possible that PCCB's, with rotors that are in the neighborhood of 10lbs lighter per wheel than their cast iron cousins, could have a positive effect on range? Just asking as someone who spec'd 21" Mission E wheels and PCCB's.

 

[JimBob]

Like most things, somewhat complicated. Here is a link to an article on Wikipedia https://en.wikipedia.org/wiki/Rolling_resistance

To get a definitive answer you would have to run a test comparing the two.

 

[Mike in CA]

Like most things, somewhat complicated. Here is a link to an article on Wikipedia https://en.wikipedia.org/wiki/Rolling_resistance

To get a definitive answer you would have to run a test comparing the two.

I agree completely that it's complicated and I've no doubt that rolling resistance, aero drag on wider tires, wheel/tire circumference etc. all have an effect on range. But so does wheel weight, so I would expect that a lower rotating mass would be beneficial and PCCB's should make up most if not all the weight difference between 19's and 21's.

As you say, the only way to get a definitive answer would be to do some kind of controlled test.

 

[kort]

I wouldn't worry. You should eventually see the ranges you are referring to, once you figure out the best configurations.

What would the best configurations look like?

 

[JimBob]

To follow the logic through. If you are driving on a track with multiple accelerations and decelerations, you probably want a lighter tire because its easier to spin up and down. On the road a bunch of other things come into play.

 

[kort]

Question. What tire pressure do you have? Big impact on range? I have 20" snow tires, pressure about 42psi at 10c.

I have 179 miles on the car. 20 inch all seaon contis, 40psi

 

[JimBob]

What would the best configurations look like?

Here is my suggestion. Run a test and see if your results make sense in the context of what other people have to say.

Most tests are in Range mode so use that.
Make sure your tires are inflated to the appropriate pressure.
Do it at constant speed say 70 mph using cruise control.
Run it for an hour if possible.
Note the air temp. If its warm where you are then you won't have to worry about the cold.

Then post the details as to the distance traveled and the battery per cent ages and see what the comments are.

 

[kort]

Here is my suggestion. Run a test and see if your results make sense in the context of what other people have to say.

Most tests are in Range mode so use that.
Make sure your tires are inflated to the appropriate pressure.
Do it at constant speed say 70 mph using cruise control.
Run it for an hour if possible.
Note the air temp. If its warm where you are then you won't have to worry about the cold.

Then post the details as to the distance traveled and the battery per cent ages and see what the comments are.

I'll give it a try when I have some time to kill

 

[Persuader]

the performance battery is the larger one

On the UK Porsche website the Performance Battery Plus is the bigger one and the Performance Battery is the smaller one.

 

[kort]

On the UK Porsche website the Performance Battery Plus is the bigger one and the Performance Battery is the smaller one.

gotcha, I have performance plus

 

[PanameraFrank]

The trip computer accurately computes regen. It will give a negative number (ie.. kWh/100 gained) if you reset it while going downhill. I firmly believe the kWh/100 number in the trip computer is as accurate of a number as we're ever going to get. I've tested it hundreds of times and it's always been completely reliable for calculating range.

Based on extensive tracking of my charging I estimate my Taycan to have a usable capacity of around 88, which lines up with your number.

I've noticed similar discrepancies with % of SOC used on the same legs of trips, one direction vs the other, but on both the front & back half of the trip. I believe it has more to do with the road & conditions.

One of my trips is 90 miles each way. I get much better efficiency on the trip there rather than the return trip. Another trip is about 110 miles each way and I get much better efficiency on the return trip. Same road, same conditions, just going the opposite direction without any marked elevation gain. I think the battery is (mostly) linear and would guess your better return efficiency was due to other factors.

Amazing range, though, 254 is remarkably good given those weather conditions. I'm guessing as the car becomes less efficient in winter you get even more benefit from the 19" wheels. I can make it about 230 miles using your conditions on my 20" wheels, so I would not be surprised if you're getting a 5-8% efficiency gain with the 19" wheels.

 

[Kingske]

The trip computer accurately computes regen. It will give a negative number (ie.. kWh/100 gained) if you reset it while going downhill. I firmly believe the kWh/100 number in the trip computer is as accurate of a number as we're ever going to get. I've tested it hundreds of times and it's always been completely reliable for calculating range.

Based on extensive tracking of my charging I estimate my Taycan to have a usable capacity of around 88, which lines up with your number.

Amazing range, though, 254 is remarkably good given those weather conditions. I'm guessing as the car becomes less efficient in winter you get even more benefit from the 19" wheels. I can make it about 230 miles using your conditions on my 20" wheels, so I would not be surprised if you're getting a 5-8% efficiency gain with the 19" wheels.

 

[Kingske]

Thanks @PanameraFrank for these very relevant reference data. If the Trip computer takes regen into account, then the usable battery capacity is indeed likely to be more than 83.7 kWh. 88 sounds about right. Referring to @daveo4EV 's explanation in this thread why relatively small aero and other differences have a significant impact on energy consumption of an already very efficient vehicle, it seems indeed reasonable to attribute a 5-8% efficiency difference between 19" and 20" wheels. That would make sense in light of the 10-15% difference which has been quoted for the difference between 19" and 21" wheels before, although I read in other threads that the delta between 19" and 20" would be smaller than between 20" and 21" wheels.

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