Plug-in Hybrid Systems Compared - Volvo vs Audi vs BMW vs Porsche

i have driven Volvo, Audi and BMW plug-in Hybrids and Porsche system is an improved version of Audi system so combined with my Electrical Engineering degree i feel qualified to make this analysis / comparison …

the PHEVs ( Plug in Hybrid Electric Vehicles ) we will compare:

Volvo S60 Recharge ( i am daily driving it )

Audi A7 TFSI 55 e ( i have driven an Audi SUV with the same exact drivetrain ):

BMW 550e ( i have driven an X5 with the same exact drivetrain, as well i have driven this G60 chassis with an ICE drivetrain ):

Porsche Panamera E-Hybrid ( similar system to Audi but with important improvements, platform shared with Bentleys - i have driven a modified version of that Platform in Audi E-Tron GT )

first up the Volvo

you have:

  • forced induction 2.0 liter 4 cylinder transverse engine in the front, that has a CISG ( Crank Integrated Starter Generator ) unit on it

  • battery mounted in transmission tunnel on top of exhaust system

  • ERAD ( Electric Rear Axle Drive ) in the back

  • Fuel Tank in normal location ( under rear seats )

Advantages of this system:

1 - battery is completely protected from physical damage in a crash. its mass is also centralized front to back and low to the ground. this is the ideal location for the battery. it can’t even be damaged by road debris because it is recessed in the floor plan of the car to make room for exhaust to run underneath it.

2 - ERAD is direct drive single gear, which means in EV mode there are no gear shifts on either acceleration or braking and it feels smooth as EV should.

Disadvantages of this system:

1 - because transmission tunnel is used by the battery the car can’t deliver the power of ICE to the rear wheels, giving it FWD ( Front Wheel Drive ) driving dynamics at the limit even though it has ( Electronic ) all wheel drive, that performs well in rain and snow. this AWD system is optimized for safety over performance as you would expect from the brand.

2 - the FWD platform with transversely mounted engine is designed for 4 cylinders and 4 cylinders ONLY. in fact all Volvo engines are 4 cylinders. Volvo went this route in 2015 when Electrification was seen as inevitable and they decided to not invest in bigger engines and focus on electrification instead. in latest iteration of this system the ICE puts down about 300 hp to front wheels while the ERAD puts down about 150 hp to rear wheels, giving the car roughly a 65% front / 35% rear torque split.

Ideal torque split would closer to 45% front, 55% rear so the disadvantages of the system are that it is inherently FWD biased and ICE torque is limited by 2.0 liter displacement.

even though turbocharging can boost power of the 2.0 liter squeezing over 300 hp from a 2.0 liter results in a peaky torque curve compared to a larger engine with smaller turbos.

the 1st gen of this system used a supercharger up to 4,000 rpm and turbo above 4,000 rpm to achieve a flat torque curve, but the supercharger was dropped when ERAD started developing better power and ICE power became less of a handicap.

even so, the 2.0 liter transverse layout with no mechanical connection from ICE to rear wheels is ultimately the limitation of this system.

this limitation is ENTIRELY ACCEPTABLE at $60,000 price point of this car, but it would NOT be acceptable at the higher price points commanded by Audi, BMW and Porsche in this comparison.

you have to understand what Volvo is. Volvo is a car that drives like an Acura ( which is one step above a Honda ) but has Scandinavian Style, Audi level seat comfort and Mercedes level safety. In addition this particular Volvo is a Plug-in Hybrid which you can’t get in an Acura because Plug-in Hybrids are a European thing ( due to tax breaks for PHEVs in place there ).

European Tax breaks for PHEVs is the reason why all cars on this list are European. It isn’t out of snobbery. The Japs simply aren’t into PHEVs or EVs due to political climate differences. The Japs are also not into Wagons or hatchbacks ( both of which are popular in Europe ).

if Lexus made a PHEV Wagon i would get it in a heartbeat. but they never will because they are Japs, thus i am forced to look at overpriced and unreliable Eurotrash.

next up Audi

so this system is different from Volvo’s …

the engine is still 4 cylinder turbo but it’s longitudinal and drives all 4 wheels directly through mechanical AWD system …

unlike Volvo that has separate CISG and ERAD the Audi has a more traditional system with just one electric motor between the engine and transmission ( BMW and Porsche are the same way ).

the Twist is that the transmission is a DOUBLE CLUTCH type.

pros of this Audi:

  • Double Clutch transmission is superior for use in plug in hybrids. though it has been a while since i drove this drivetrain i remember being impressed by it as much as i remember being disappointed in the BMW’s drivetrain due to its use of regular transmission.

  • AWD system works the same whether you’re on EV or ICE power ( BMW and Porsche are the same )

  • hatchback opening makes it easy to put a bicycle in so you can drive to a trail and have a good cardio workout there without fear of being hit by a car.

cons of this Audi:

  • battery location is very poor. not only is it very high up ( bad for center of gravity ) but it completely blocks all trunk space underneath it. this was a deal breaker for me. not because the trunk is unusable but because the level of stupidity of that design was unconscionable to me. i should note some of the space under the floor is used by the subwoofer but the sub could have been placed anywhere else in the car.

  • 4 cylinder engine is out of place on a $70,000 base MSRP car. the Volvo is $60,000 fully loaded. the Audi is $70,000 bare bones. at this price you want more than 4 cylinders - hybrid or not. this was another deal breaker.

  • audi’s four cylinder engines are CAST IRON when even Toyotas use Aluminum engine blocks … this was yet another deal breaker for me. Audis of course are notorious for being nose heavy - more on this later …

turns out i wasn’t the only one who felt this way because that car has been discontinued in USA ( good riddance ).

in Europe the tax incentives for plug in hybrids are so massive and gas so expensive that this car makes perfect sense there. people there don’t want more than 4 cylinders ( due to gas prices ) and they DEMAND a plug in hybrid system ( for tax breaks, even if they have nowhere to charge ) and the styling of that car is bang on and people in Europe like hatchbacks so that car makes perfect sense there …

but it makes NO SENSE in America. in America people would rather buy a V6 SUV that will be faster and have way more cargo space and it will be cheaper too. i can’t really blame them.

i wanted the convenience of hatch opening for transporting a bicycle but couldn’t justify price difference over Volvo for a car that is on the whole just as compromised as Volvo is.

next up BMW:

note images above are for the European hybrid that has 4 cylinder, whereas American model will have inline-6 engine that will fill out that empty space in the chassis seen in the images above.

the BMW system is similar to Audi in that there is a mechanical AWD system and a single electric motor between Engine and transmission but there are a few differences from the Audi, namely:

  • BMW uses regular ZF 8HP transmission

instead of 7 speed double clutch in the Audi …

now the ZF 8HP is widely regarded as the best Automatic transmission ever made but it is still no match for double clutch, especially in this application where it loses the Torque converter to make room for the Electric motor …

  • BMW uses a pre-gearing stage on electric motor which ensures the motor rotates at 1.9X the RPM of the engine, which is smart because the motor has 1.9X higher redline than engine. this boosts effective torque of electric motor to about 330 foot pounds however the Audi and Porsche electric motor has about 290 lbs as well even without pre-gearing stage so they probably just use a slightly larger motor there.

the reason to use a pre-gearing stage versus a larger motor is gears are made of steel while motors use copper and neodymium so as BMW system is newer and designed for use in more affordable cars ( as most cars today have to be hybrids ) it must be more frugal with semi precious and rare earth metals. by contrast the Audi was a premium product further back in time when there wasn’t as much a scramble for minerals as there is now so they just went with a larger motor.

  • BMW places the battery under the floor of the car instead of in the trunk. this is overall a better location than Audi’s but not as good as Volvo’s. it’s better than Audis because it’s lower to the ground and also more centrally located front to back of the car … but the downside is it requires mechanical protection from both side impact and road debris and this adds weight.

to make matters worse in dedicated EV platform cars like E-Tron GT the heavy battery protective housing is used as part of car chassis to improve stiffness and handling but BMW is not a dedicated EV platform and the protection on the battery is just dead weight on the car. but at least that weight is in the best possible location for handling - under the center of the car.

now that car isn’t out yet so i couldn’t test drive it but i test drove the gas model ( 2024 530i ) as well as X5 50e that uses the same hybrid system but in a different body and … i was not impressed.

the problem with sedan body is that with the spare tire kit there is basically no trunk space left and also despite huge car dimensions interior space is not any larger than Volvo’s. this is because a lot of space is used by the long hood of the car ( to accommodate longitudinal inline 6 engine ) and also the battery under floor lifts the car up and the seats are also high plus the transmission tunnel is wide so at the end of the day you get a car that is billed as being a size up from Volvo but is exactly the same size inside. the abysmal trunk is what really gave me pause - this generation 5 series is bigger and heavier than 7 series used to be yet the trunk space with the spare tire kit is smaller than in a Honda Civic hatchback.

the drivetrain gave me pause as well. B58 engine is the gold standard and the electric torque multiplied by the pre-gearing stage works as advertised but … the transmission is a poor fit for this setup. the Z8 HP was meant to work with a torque converter not electric motor … the motor has so much inertia that to avoid breaking the transmission power must be cut before shifting gears and this is very noticeable …

there is a huge surge of torque from B58 plus Electric motor and then it just stops and there is a long gap while transmission rev matches and shifts then the power comes back … there is also a similar delay when coming off the line as well … frankly once you drive an EV like E-Tron GT you will never accept this nonsense …

between the non-existent trunk, a transmission that takes an eternity to shift ( because it was never designed for the inertia of electric motor and has to wait for it to slow down ) and a compact car sized interior in a car that has size, weight and cost of a full size car, plus styling only a BMW fanboy could love … yeah, i’m not sure about that one.

finally the Porsche

the system is similar to Audi’s ( as both Audi and Porsche are under VW ( VolksWagen ) umbrella ) but there are key differences …

  • instead of an old 7 speed double clutch the Porsche uses a new 8 speed design, but more importantly the Porsche transmission isn’t a transaxle like Audi which allows it and the engine to mount deeper into the chassis for better weight balance … essentially Audi engines are always in front of the axle because to save money they eliminated the front propeller shaft and the axles go straight into the transmission, which allows them to offer bargain priced AWD but at a cost of poor weight distribution …

  • instead of cast iron ( cheap but heavy ) 4 cylinder that Audi uses the Porsche has an Aluminum V6 as the base engine ( V8 is available )

  • instead of battery being on top of the trunk like in Audi the battery is IN the trunk ( all the way down ) in the Porsche

i never looked at the Porsche until last week because knowing the prices in my mind it would be a waste of time to even consider as i have assumed that being under same umbrella as Audi the system would be basically the same just at a higher price …

what i haven’t realized is that the Porsche solved all of the problems that Audi has … even though it actually came out YEARS BEFORE the Audi …

and that’s when i realized that MARKET SEGMENTATION was at work …

market segmentation is when some products are DESIGNED TO SUCK in order to protect the value proposition of more expensive products …

i was SEETHING when i saw the stupidity of Audi’s design and couldn’t understand how German engineers could be so stupid … well they weren’t. they were ORDERED to ruin that car.

everything in the Audi is wrong - the Engine is wrong size ( 4 cyl instead of 6 ), wrong material ( iron instead of aluminum ), wrong position ( too far forward ), the battery is wrong shape and in wrong place. there was so much stupidity in that beautiful car i wanted to choke myself.

but as usual when smart people make such dumb “mistakes” there is a reason … and the reason was that Audi A7 was designated to be inferior to the Porsche Panamera and inferior it is … IN EVERY WAY

engine is smaller ( by a third ), battery is smaller, trunk is smaller, fuel tank is smaller ( by a third ), interior is smaller, wheels are smaller and the transmission has 1 less gears … this is despite both cars being roughly the same size

the reason fuel tank is smaller in Audi is because when the Audi put the battery in the wrong place they didn’t just waste all of the space underneath it they also cut into the area where half of the fuel tank in the Porsche was. mind you they did this AFTER they already knew the right way to do it because Porsche came first … they DELIBERATELY moved the battery from the right location to the wrong one to make everything worse. now THAT is what i call German engineering !

in Audi’s defense the Prius Prime at the time had the battery in the same location as Audi but that’s because the Japs are fucktarded. the Germans KNEW where the battery SHOULD be but PRETENDED that they didn’t know and put it in the same location where it is in the Prius to make the car worse so it doesn’t step on Porsche’s toes.

well to play the devil’s advocate the Audi’s battery has single level cooling design whereas Porsche’s is two-level. it is basically Audi’s battery but folded in half for space saving. compare Porsche battery:

to Audi battery:

this folding does add additional cost / complexity and you could argue that in a cheap car like Prius the buyer might not want to shoulder this cost … but in an Audi A7 i expected better …

of course the Porsche was about $30,000 more than Audi but like an idiot i assumed they would be close since they are made by the same company and they have such similar overall dimensions …

but kudos to VolksWagen group they went out of their way to protect the Panamera by royally fucking up the Audi on purpose …

OK maybe i’m too harsh on Audi - there are actually some cost saving benefits to their solutions over what the Porsche is using - i guess i just never realized how much cost cutting is actually happening in a car like A7 … it’s almost as outrageous as when Tesla removed the entire Dash from Model 3 to make it cheaper than Model S …

now the Panamera Hybrid is $120,000 but a certified pre owned is $70,000 which puts it on a more level playing field with the other 3 options in this list.

i haven’t driven the Panamera yet but i drove an Audi PHEV that has same electric motor and similar double clutch transmission and i drove E-Tron GT that is built on Panamera’s platform as well as has similar body style and based on those experiences my expectations for Panamera Plug-in Hybrid are pretty high …

but then so is the price … is it worth it ? only a test drive can tell.

a refreshed Panamera was announced 2 weeks ago. my hope is once the hybrid version of the refreshed Panamera goes on sale people will start to trade in their 3 to 4 year old hybrids for a new one and there will be some decent CPO ( Certified Pre Owned ) deals to be had …

right now the only decent deal on a Panamera Hybrid is all the way in Boston ( a whole day of driving for the round trip from NJ ) and even that deal isn’t that great.

but since i am buying out the Volvo with 1 year of warranty left i will have an entire year to wait for the right deal to come up hopefully closer than Boston.

i may have to buy extended warranty for Volvo and wait longer than a year depending on how the situation develops.

if i were to switch now i would be giving up a $29,000 car ( my buy out price on the lease ) with 17,000 miles to buy a $68,000 car with 41,000 miles and that’s a really shitty deal.

but i hope the situation will change a year from now due to the refreshed model coming out. if not then i will have to drive the Volvo a bit longer until it starts showing signs of age before getting something else.

by then of course EVs may be the way to go. they are already the way to go as far as car itself is concerned but the charging network outside of Tesla is nowhere near ready for prime time.

really the Volvo is super hard to beat. the seating position is low and Porsche like. transmission tunnel is narrow allowing you to not be pressed into the door. you get 4 cylinder hybrid fuel economy with sub 5 second acceleration. you get high grade leather interior, panoramic moon roof and all wheel drive plus Scandinavian styling and you have all this for HALF the price of the BASE Porsche that has the same exact acceleration.

yes of course the Porsche is better. in addition to points previously discussed it has things like soft close doors and ventilated seats for example. but does that make it worth DOUBLE what Volvo costs ?

i need to test drive it. no other way to know.