So, has there really been no credible news…

[ptsturbogt]

Here's some fully achievable numbers based on an Boxster EV:

• 0.25 CD - this is reasonable. A Taycan is 0.22. A Cayman EV should also be 0.22
• Not a skateboard platform. Battery behind seat. Doable now with modern energy dense batteries. This preserves lower height which aids driving position, handling and range.
• Overall 10% lighter, with a lower Polar Moment of Inertia, lower Center of Gravity, and fine throttle control of an electric powertrain.
• 60 kWh = 300 mile range at 70 mph.
• 10C charging means 2X-2.5X faster than the Cayenne Electric.

	Weight (lb)​	Total​
2025 Boxster GTS with PDK	3241​	3241​	With fuel
PDK Transmission	-247​	2994​
Engine with Accessories & Exhaust	-552​	2442​
Fuel System with Fuel	-115​	2327​	90 lb fuel
Cooling System weight reduction	-20​	2307​	50% reduction
250 kW (335 hp) Twin Torque Vectoring Rear EESM Motors	+183​	2490​	Using Lucid Atlas & BMW iX3 data. This will smoke a current GTS.
60 kWh Battery	+528​	3018​	CATL Qilin Condensed. Expensive but compact, light and 10C charging.
LFP 12V Battery	-33​	2985​	Using 718 Antigravity. OEM design would be even lighter.
Zonal Architecture	-20​	2965​	New Rivian architecture which is coming to Porsche.
25mm Narrower Tires & Wheels	-20​	2945​	About 10% reduction in tire width which is same as weight reduction.
Lighter Brakes	-15​	2930​	Lighter vehicle plus regen effect.

how would you get to 300mile range from 60kW battery? 5.0m/kW is ridiculously efficient and even the Lucid Air that did that hasn't ever been replicated in real world driving. @70 mph no chance.

 

[babylou66]

how would you get to 300mile range from 60kW battery? 5.0m/kW is ridiculously efficient and even the Lucid Air that did that hasn't ever been replicated in real world driving. @70 mph no chance.

The numbers are mostly laid bare but I'll try to expand a bit:

• Powertrain Efficiency is based on BMW's EESM + SiC inverter. The coefficient can be back calculated. This technology has been in use since 2024 in the iX. An EESM (Externally Excited Syncronous Motor) is more efficient for highway use (high speed + low laod) than a PMSM (Permanent Magnet Synchronous Motor) that is used by Lucid and most others. A PMSM is most efficient in city driving with high load and low speed.
• Frontal Area reduction. A Boxster is 5" lower than a Lucid Air and 6" narrower. The width can also be another 2" narrower than a Boxster GTS using 25mm narrower tires but maintaing the same load due to the ~8" weight reduction.
• Coefficient of Drag does increase about 5% versus an Air.

I know this stuff as engineering is my life and my passion. Why else would I mine this data and do these calculations?

 

[ptsturbogt]

The numbers are mostly laid bare but I'll try to expand a bit:

• Powertrain Efficiency is based on BMW's EESM + SiC inverter. The coefficient can be back calculated. This technology has been in use since 2024 in the iX. An EESM (Externally Excited Syncronous Motor) is more efficient for highway use (high speed + low laod) than a PMSM (Permanent Magnet Synchronous Motor) that is used by Lucid and most others. A PMSM is most efficient in city driving with high load and low speed.
• Frontal Area reduction. A Boxster is 5" lower than a Lucid Air and 6" narrower. The width can also be another 2" narrower than a Boxster GTS using 25mm narrower tires but maintaing the same load due to the ~8" weight reduction.
• Coefficient of Drag does increase about 5% versus an Air.

I know this stuff as engineering is my life and my passion. Why else would I mine this data and do these calculations?

so from all of those numbers, your thinking 5.0kW/mile for the overall efficiency? that would be awesome if that happens.

 

[babylou66]

so from all of those numbers, your thinking 5.0kW/mile for the overall efficiency? that would be awesome if that happens.

It is fully possible. Will Porsche do it? I have no idea but I sure hope so. So far they have not used EESM's but who knows. Another method to improve highway efficiency is to use a multi-speed gearbox like the Taycan rear motor. This is why the Taycan has great range on the highway relative to its rating (pick your favorite) because the ratings are skewed toward lower to medium speed driving. I prefer the EESM over a two speed motor because EESM is a bit smaller, lighter, lower cost, does not need rare earth materials and is overall simpler so likely more reliable.

 

[babylou66]

Here's some calcs:

• 2026 BMW iX XDrive 45
  • EESM front and rear motors
  • SiC inverters
  • Front motor not used during cruise
  • 100.6 kWh gross battery capacity
  • 94.8 kWh net battery capacity
  • 338 miles 70 mph real world tested range - aggregate of three tests (journos and YouTubers)
  • 7.7 ft^2 CDA (this is frontal area X coefficient of drag)
• Porsche Boxster
  • 25mm narrower tires than the GTS 4.0 which equals same contact pressure because the EV will be lighter if it uses semi-solid state batteries
  • 20.7 ft^2 frontal area due to 2" than GTS due to narrower tires. This will not affect cabin interior width.
  • 5.0 ft^2 CDA. Assuming 0.24 CD. Porsche Taycan is 0.22 so I feel this is a reasonable goal for Boxster. Cayman should hit 0.22.
  • Let's use 60 kWh gross and 57 kWh net for battery.

338 X (57/94.8) X (7.7/5.0) = 313 miles @ 70 mph

 

[babylou66]

And I do realize the above calc ignores rolling resistance, friction losses like seals and other power losses like steering, HVAC, ETC. Those are basically "in the noise". The second largest loss, rolling resistance, is even more favorable than the aero.