hmmm - my lovely Taycan is limited to 220 miles range - [Edit] I think it's the tires…

[daveo4EV]

PMCC Energy Graph for the charging session shows no tapering during the session…therefore I think it's reasonable to assume the ratio of "raw" power to "battery" power is mostly constant…review of the graph below clearly indicates a linear/constant charge rate of approximately 9.6 kW…with only minor fluctuations…

based on the graph below I see no reason to assume the battery charge rate deviates from the observed 7.7% delta between the raw power input rate (9.6 kW) to the observed "in car" rate reported by the Porsche Charging User Interface (8.86 kW)…that's an overhead of 7.7% and is inline with my experience for EV charging since 2013.

I welcome any data showing a 20% overhead in a non-thermally challenged environment.

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[Miwa]

Good tires will easily lose you a bunch of range. Which shows just how bad no-season tires are for actually gripping the road.

I've been super tempted to swap out the horrible tires on the Bolt forever, but it's my wife's car and she'd notice the range loss too much.

 

[LonePalmBJ]

sticker tire = increased rolling resistance - by my calcs using 230 miles w/Summer tires as "my range" vs. 260 miles based on my experience with the continentals that's an 11.5% whack on range just for swapping the tires.

FWIW, Road and Track tested this by swapping the tires on an e-Golf and saw a 20% range hit:
https://www.roadandtrack.com/new-ca...stickier-tires-impact-an-electric-cars-range/

Edit: The author also installed larger wheels, which honestly is probably the larger factor in the decline

 

[daveo4EV]

my conclusion is "tires" - in reviewing my past charging sessions with PMCC data - I can find no data to indicate "lower battery capacity" - all charging for daily drives and such are in line with 2.7 mi/kWh consumption rate - which is higher than I have observed in numerous previous trips (many documented on this very forum) - and the increased consumption lines up with my Tire swap in the July/Aug time frame when I took the vehicle in for:

1. the drive train fault software update
2. swapped the tires due to wear while at the dealership to save myself another service visit

to me the data pretty clearly indicates at least an 11.5% "hit" for the sticker summer rubber - good year F1 tires…which is bummer IMHO - but good to know.

the really really good news here is with 15k miles on the car and about 1.5 years and numerous fast charging sessions (not overwhelming) that Porsche's battery degrading is minimal to non-existent - which is happy happy new for all of us.

 

[ciaranob]

my conclusion is "tires" - in reviewing my past charging sessions with PMCC data - I can find no data to indicate "lower battery capacity" - all charging for daily drives and such are in line with 2.7 mi/kWh consumption rate - which is higher than I have observed in numerous previous trips (many documented on this very forum) - and the increased consumption lines up with my Tire swap in the July/Aug time frame when I took the vehicle in for:

1. the drive train fault software update
2. swapped the tires due to wear while at the dealership to save myself another service visit

to me the data pretty clearly indicates at least an 11.5% "hit" for the sticker summer rubber - good year F1 tires…which is bummer IMHO - but good to know.

the really really good news here is with 15k miles on the car and about 1.5 years and numerous fast charging sessions (not overwhelming) that Porsche's battery degrading is minimal to non-existent - which is happy happy new for all of us.

Interesting indeed - I notice that the std 19" wheels come with Performance Summer Tires (at least for the Houston market) - I ordered the 21" Cross Tursimo wheels that presumably would also be shod in Perf. Summer tires by default but I just noticed that there is a $0 option to have All Season tires instead (really was not interested in this option but seeing the big range hit I may have to reconsider). Anyone know what tires these might be (manufacturer/spec) and obviously curious if on a 21" wheel how much difference there might be on range hit effect vs 19" wheel - assume range impact will be a combo of wheel size and tire compound - I would assume the tire grip the bigger factor on range?

Spec for tires on 21" wheels but no mention of tire brand nor any differences if All Season chosen:

 

[JimBob]

I agree in theory - charge rate however does not taper for 240V charging until one is above 93% SOC - until then charge rate is mostly linear…but yes you are correct I'm assuming charge rate losses (raw vs. actually battery kW charge rate) is mostly linear…

my ownership period of EV's since 2013 I've found charging losses routinely run in the 5-8% range - unless weather is a factor - i.e. super cold (50F or less or over 90F) - I"m in mild temps - so charging rate losses are in line with my experience and expectations - 20% charging overhead is very very high - and AC/DC inverters tend to be 9% loss or less…

20% charging loss routinely would dramatically affect the efficiencies of EV process and I've never seen any "real cost" studies that estimate them that high (unless of course again environmental conditions are causing additional drain during the charging process - again mostly do to cold weather charger which was not a factor here).

Couple of points.

First your assumption of a flat linear charging curve in the interval you indicated looks ok.

AC DC inversion is very efficient at around 95% but there other energy losses that raise this number. A quick search will indicate a higher range. Here is one from Car and Driver https://www.caranddriver.com/features/a36062942/evs-explained-charging-losses/

I think the EPA has a number as they estimate energy at the wall. I just haven't found it yet.

In any event this number has the potential to swamp the perceived efficiency you see and should be either accounted for or rejected.

Also note the comments that charging the battery to 100% will generate higher losses. As you are trying to measure the net battery capacity you have to take it all the way to 100% to be accurate.

 

[Wakesurfer]

I've canceled my service appointment - I don't think the battery capacity has changed - calculations shown below:

Green Cells are "data entered manually"
Blue Cells are "calculations from the manual data"

conclusion I'm getting 2.7 mi/kWh - which exactly equals 224 miles of range at that consumption rate - I recently moved from Factory Continental All Seasons to Goodyear Eagle F1 tired (N
F0) - the Goodyears should be a sticker tire - so that may account for the consumption numbers.

in any case my charging sessions data indicated a usable battery capacity of 83.76 vs. 84.3 stated by Porsche which is a 0.77% loss of capacity

I'm going to keep more data and keep checking it - but for now I'm blaming the tires and increased consumption.

my consumption is pretty clearly 2.7 mile/kWh - which means maximum range calculates out to 224 - range isn't going to get better until I get my consumption numbers to be better.

in any case this is some pretty good data regarding the sort of range I'm seeing with the Goodyear F1 tires for Taycan - pretty heft range hit IMHO - may not be worth it for the extra sticky…

Question. If you go to the Connect app what is the miles driven/kWh prior to the new tires? Closer to 3 or 3.1 maybe? Interestingly I find that driving around town with a lot of stops and starts my miles/kWh is around 2.4 to 2.5. On long trips where I get on the highway even at 75-85mph the miles/kWh increases to 3.1 to 3.2. Clearly the stop/go in town takes a lot of battery power. I am very surprised that sticky tires pull the miles/kWh down so much. I don't disagree with your assessment just surprised at how sensitive these cars are to the 'little' things that we take for granted in an ICE vehicle where the measurement of miles/gallon is more like 'who cares.............I'll just stop and fill up'.

 

[porsche_coyote]

I've canceled my service appointment - I don't think the battery capacity has changed - calculations shown below:

Green Cells are "data entered manually"
Blue Cells are "calculations from the manual data"

conclusion I'm getting 2.7 mi/kWh - which exactly equals 224 miles of range at that consumption rate - I recently moved from Factory Continental All Seasons to Goodyear Eagle F1 tired (N
F0) - the Goodyears should be a sticker tire - so that may account for the consumption numbers.

in any case my charging sessions data indicated a usable battery capacity of 83.76 vs. 84.3 stated by Porsche which is a 0.77% loss of capacity

I'm going to keep more data and keep checking it - but for now I'm blaming the tires and increased consumption.

my consumption is pretty clearly 2.7 mile/kWh - which means maximum range calculates out to 224 - range isn't going to get better until I get my consumption numbers to be better.

in any case this is some pretty good data regarding the sort of range I'm seeing with the Goodyear F1 tires for Taycan - pretty heft range hit IMHO - may not be worth it for the extra sticky…

I'm glad it's nothing more serious. And thanks for taking one for the team. I was thinking of getting the F1s to replace my all-season Contis. Food for thought.

 

[ciaranob]

I'm glad it's nothing more serious. And thanks for taking one for the team. I was thinking of getting the F1s to replace my all-season Contis. Food for thought.

How do you find the all season Continentals vs any equivalent Perf Summer tire or have you only used All Seasons with the Taycan? Thinking not just handling metrics but any tire noise comparisons etc.? Have believe it or not never had All Seasons on my M cars so literally have no personal experience in the comparison to guide me! Thx in advance.

 

[porsche_coyote]

How do you find the all season Continentals vs any equivalent Perf Summer tire or have you only used All Seasons with the Taycan? Thinking not just handling metrics but any tire noise comparisons etc.? Have believe it or not never had All Seasons on my M cars so literally have no personal experience in the comparison to guide me! Thx in advance.

I've only ever had the all seasons on my Taycan. I did drive a Turbo S (same wheels) w/ the Summer tires at PECLA, and it definitely felt a lot more grippy.

 

[Miwa]

It's often more than just grippiness, better tires just have a much better feel, even when not anywhere near the limit, that can be really obvious. The Taycan is so heavy that it might not be as noticeable though.

 

[ciaranob]

It's often more than just grippiness, better tires just have a much better feel, even when not anywhere near the limit, that can be really obvious. The Taycan is so heavy that it might not be as noticeable though.

Thx, yes I entirely appreciate the benefits of Perf Tires, road and track, all I have owned - my query was more on how bad might the All Seasons be in every day use!

 

[Jhenson29]

AC/DC inverters

AC DC inversion

AC->DC = rectifier
DC->AC = inverter
?

 

[feye]

7.7% for charging overhead. How do you estimate it?

These are the first 4 full charges I made with 11kW Porsche Charger. I have over 15% loss. Could be because of 3 phase slightly faster charging...

 

[feye]

My home charger keeps a record of how many kWh it has supplied to the car, so I will be able to make an estimate of battery condition based on change in % charge against kWh supplied.
I must remember to set up a spread sheet to follow it from when the new one arrives.

Yes, please do so.

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