walls99

Hi All,

New member here. Sorry if I am asking a question already posted. Forgive if my questions are all over the place.

I want to get a better understanding of the cost of charging the E-Hybrid. Humor my hypothesis and let me know if I am way off. The capacity of the battery is 17.9 kWhs. If I consider the inefficiency in charging lets say it costs 20kWh to charge. Give the price of 1 kWh is 10 cents in Virginia, that will cost me $2 every time I charge, correct? Does the fast versus slow charge time determine the amount of power used/wasted during charging. I am willing to charge slower if it extends the life of the battery. If I can get 20 miles to the battery that translates to 10 center per mile on electricity versus, if a gallon costs $3.80, that translates to 18 cents per mile at 21 mpg.
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Another thing I want to get some feedback on is, is it worth it to get a Hybrid based on our driving needs. Both of our commutes have city/highway miles. Mine is 100 miles a day and my wife drives 40 miles. I might have a chance to charge at work. No chance for my wife. If I drive it 2 days a week and my wife drive 3 days that translates to 320 work miles: 100 miles on battery and 220 miles on gas. Is it still worth it to get the Hybrid ?

The price difference between the base and E-Hybrid is $7200 after the govt rebate, but no one knows what the rebate will be in 2022. We normally change cars after 5 years, but given that we are spending 100k on this, we plan to keep it for 7 years at least.

Thanks in advance.
Wally

JustinL

You have a very long daily commute and that's where the hybrid is going to lose out. No matter what you do, the hybrid is going to be more efficient, but the gap narrows the longer the trips are. The other benefit of the hybrid is performance, so a closer comparison might be the S.

daveo4porsche

the speed at which the water flows does not change the size of the bath tub - i.e. the volume of the tub - or gallons of water - slower water flow just takes longer to fill the tub - but at the end is the same amount of water - i.e. 50 gallons

the slow vs. fast charging for a Hybrid is either 3.6 kW or 7.2 kW - that’s the flow - gallons/capacity is 17.9 kWh - you are billed by capacity/volume (kWh) - NOT flow rate (kW)

it costs the same to charge the hybrid no matter how slow/fast you fill it - because at the end of the day you need to pump 17.9 kWh (kilowatt hours) into the battery - it will take about 20 kWh of billing +/- to “fill” the battery at what ever rate you do it.

the impact to the batteries longevity for slow/fast charging also tends to only apply for larger batteries charging at MUCH MUCH MUCH faster flow rates - like the Taycan can charge as slow at 1.44 kW or as fast as 270 kW - that’s a 200x multiple an range of charge rate - if you were to charge a Taycan every single day at 270 kW there might be some accelerated degradation - but it would be hard to measure across the 8-10 year/250,000 mile life of the battery…

there is virtually no difference/impact to a hybrid battery at 3.6 kW vs. 7.2 kW - the charge rates need to be much much higher before that becomes a factor

17.9 kWh / 3.6 kW = 4.97 hours to charge teh battery - call it 5.5 hours
17.9 kWh / 7.2 kW = 2.486 - call it 3 hours

the 7.2 kW charge rate means you can charge once after morning errands and the car will be “full” again for afternoon errands - and then again overnight for the morning

get the faster charger and don’t sweat the charge rate - the fast vs. slow moniker in this context is laughable since neither are particularly “fast”

there are two things you never hear from an EV owner:

1. my EV goes too far on a single charge
2. my EV charges way to fast I need it to slow down

get the faster charger - you are much much much more likely to run into problems with the traditional ICE motor in predictable mechanicals failures endemic to all complex mechanical ICE motors than you are to impact your Hybrid’s battery life.

walls99

Thanks for the details on how the charging works, daveo4porsche. Appreciate it.

daveo4porsche

I’m routinely getting 24-27 miles with the ‘21 TurboS eHybrid
gas for me is $4.50 or more - 21 mpg - LOL - I wish

my math for the past 7 years on EV vs. gasoline is EV = 1/3rd cost per mile of gasoline @ 28 mpg - that is a pretty good rule of thumb. Gas is $0.15/mile and EV miles a $0.05/mile has been my math backed up by data.

your math checks out and might be a little conservative.

the cumulative effective of daily driving an Hybrid is impressive - my wife and I just finished this morning 870 miles on a “single” tank of gas - that’s what can happen across 2 or 3 weeks of nothing but short trips where 90% of them are EV only or less than 3-5 min of ICE motor time for daily errands.

walls99

Thanks for the details about the point of diminishing returns. I would get the S in a heart beat, but trying to justify the extra cost is an easier argument with the Hybrid

walls99

Thanks for some real world numbers, daveo4porsche.

In your first sentence did you mean to laugh at the price of gas or at my hoping to get 21mpg on the E-Hybrid with the gas engine ?

Thanks again

kayjh

The US fuel economy site has a handy calculator button when you use the “compare side by side” utility. You input your driving habits, electricity cost and fuel cost, miles driven per year (broken down by weekdays, weekends and long trips) and whether you have access to charging at work. It works out your annual fuel cost. Personalize then press the Hybrid button. You can find it here: https://www.fueleconomy.gov/feg/Find...n=sbs&id=43775

daveo4porsche

Hybrid will be better than the S performance wise cause the EV motor is instant torque - also the Hybrid squeezes every ounce of power out of the car and I’m constantly amazed at often the ICE motor is shut down and I’m running on “pure” EV power even when the battery is “empty” - the whole thing is just “better” over all cause the two motors are working together and Porsche’s software is just excellent at switch between the two power units or combining them for what ever circumstance the vehicle is in - it will also prepare you and accelerate your comfort level with pure EV cars which are in your future…the Hybrid is a great place to start…

when having the electrician come out to install your EV charging plug - recommend you “over” do it a bit for your eventually EV…do it once rather than multiple times over the next few years…

I’ll find the link for my diatribe on this topic and post it shortly…

daveo4porsche

yes 21 mpg is a fantasy for the Turbo - the base Cayenne might be more realistic - but it’s a porsche and they encourage spirited driving - both the base and the Turbo can be quite thirsty if driven in the manner they excel at - it’s also safe to say gas isn’t likely to get cheaper over next several years…so the math for EV driving just gets better as gasoline goes up in price…

daveo4porsche

these links might be helpful

https://rennlist.com/forums/cayenne-...rd-review.html
https://rennlist.com/forums/cayenne-...s-1400-km.html
https://rennlist.com/forums/cayenne-...s-ehybrid.html
https://rennlist.com/forums/cayenne-...in-hybrid.html
post #26
post #32
post #37

https://rennlist.com/forums/taycan/1...-charging.html <——— this thread - very well received

walls99

OK, I understand now. We are getting the Porsche to drive it like it was meant to be driven

walls99

I'll check it out thanks, kayjh

Ericson38

We are planning on getting a 2023 Cayenne in about 6 mos to replace our 957 base with 161K miles.

I was using the calculator (handy) at My Plug-in Hybrid Calculator (fueleconomy.gov)

I plugged in our California energy cost at 31 cents per kW, and our price per gallon at $6.80 for premium.

For a 1200 a month profile with 1 charge per day and 5% combined stop and go driving, the calculator came up with:

1200 miles
$254 in fuel cost for 818 miles at 21.8 mpg (68% of energy)
$81 in electricity costs for 382 miles using 269 kWhours (32% of energy)

If the 382 E miles would have been gasoline miles, it would have cost $119 at 6.80 a gallon using 21.8 mpg.

The additional cost over the $81 PG&E bill (if full ICE) is $38 for this 1200 mile monthly travel estimate.

Scale this up to 120,000 miles and it would have cost an additional $3800 (being a total ICE SUV).

Its almost not worth it to me to go Hybrid on the Cayenne, since over the life of the vehicle, I paid an additional $3800 over an 8-9 year period. And there is no battery to worry about or haul around.

Actually, the pure ICE car may get closer to 22.5 mpg, since it is not hauling the additional 600 lb battery around.

daveo4porsche

most of my daily miles are pure EV - if you move to PG&E's EV biilling program and charge the hybrid "off peak" the costs are way lower ($0.14 kwh/less)

we can go weeks with the ICE motor never starting…

we have 14,000 miles on the Hybrid - 8000 of which are EV miles - if we don't road trip - a tank of gas lasts in excess of 900 miles of driving - and pure EV miles is about 2.8 miles/kWh - or less than $0.04/mile to drive…

it all comes down to how much pure EV vs. ICE driving you do - but the numbers your using don't match my usage for the past year…YMMV