HassaanAbdeen

Hello everyone,
Tempted to place an order for the new Macan EV turbo, but since I never owned or tested an EV before I have the following noob question:
How do you downshift in an EV?

In a manual, the answer is straight forward using the stick..
In a PDK, the answer is paddles..

but how do you downshift in an EV going downhill (for example) without engine braking? If the answer is using the brakes, then doesn’t this cook the brakes?

ipse dixit

You don't "downshift"

The Macan EV uses a single speed transmission that has two gear sets.

And no using the brakes (as intended) does not "cook" the brakes, unless of course you're tracking the Macan EV.

daveo4porsche

single speed transmission - no need for shifting - linear torque from zero to max RPM's - with Macan Turbo top speed is 163 mph?

you'll be fine.

daveo4porsche

down hill in an EV has regen when you touch the brakes - so you charge the battery if you apply light braking - with Porsche there is some super light regen when off the accelerator but not touching the brakes, but very very light and non-intrusive - you actually gain battery while traveling down hill say on I-80 coming down from Tahoe - you can actually arrive at the bottom of I-80 entering Roseville with more battery than you left Truckee with…

also doesn't over heat the brakes since they are not used for Regeneration - when doing some pikes peak runs - and the down hill section there is a mandatory "stop" mid way down the hill to check brake temps - the Audi eTron when being tested arrived and recorded the lowest brake temps _EVER_ because all the speed control on the downhill segments was handled by light braking and EV motor regeneration - with the friction brakes almost entirely unused for the entire downhill segment…

https://www.cnet.com/home/electric-v...-braking-test/

daveo4porsche

you'll run out of Battery Thermals and tires well before "cooking" the brakes on most EV's on track…Porsche brakes will easily outlast the max temperature of the battery before the computers limit full power due to high battery temperatures.

the battery will be overheated causing loss of full power
and the tires will be greasy and losing grip long before you overcook the brakes due to the weight

once you're down on power, and your tires are greasy the demand on your brakes is also less given slower overall speeds…

brakes are not a limiting factor for full pace track time on most EV's I've experienced (except Tesla factory stock brakes - 3 laps at thunderhill and they were done on my 2018 Model 3 performance).

daveo4porsche

at the Macan EV briefing @ PECLa i just attended yesterday regeneration handles most/all normal braking up to 0.4 g's of deceleration - no friction braking is used unless you exceed 0.4 g's or there is not enough kinectic engergy (slow speed) to slow the vehicle effectively - Porsche is briefing press and future owners that the regeneration on Macan EV is expected to handle normal street driving deceleration for 98% of the vehicle's needs in this space - this is up from the 90% brief provided during Taycan roll out…

attending a Taycan talk at my local Porsche dealer this picture/slide was presented showing that on Taycan 0.38 g's or less is entirely handled by EV motor regeneration with no friction pad usage…expect life of brakes on Taycan and pads are covered in Porsche owner's manual and recommended service is time based @ 6 years due to expected lack of any actual meaningful pad wear.

basically with Porsche EV's unless you are routinely exceeding 0.4 g's each time you slow down you're not using the friction brakes - your vehicle is slowed down purely due to turning it's kinetic energy into electricty stored in the battery by way of running the EV motors as a generator…so your brakes honestly don't get used.

daveo4porsche

with Macan you actually have quite a bit of "engine braking" - the Porsche representative quoted 240 kW of "engine braking" is max amount of regeneration…so regeneration _IS_ engine braking - and you invoke it when you touch the brake pedal - and Porsche software decided if it needs to "add" the friction brakes into the equation…

you actually have a massive amount of "engine braking"…and recover battery power in the process.

HassaanAbdeen

Thank you very much Dave for all your detailed answers… much appreciated.