I bought this used with 70,000 miles, it now sits at about 86,000. This may be a bit poorly structured so I apologize in advance, but here are my thoughts.
HYBRID SYSTEM
It's a practical car if you mostly putt around town as I do, but the electric range of the 12kWh battery pack is severely limited in temperature extremes. When it's below 50 degrees or above 90 you'll only get 17-18 miles, likely much less in a colder climate. Closer to 70 degrees and you can expect 23-24 if you're in a pleasant mood, 21 if you're not.
I discovered that the battery charge range is software limited between 30-90% real SOC in the USA. Through coding, I was able to reduce it to the European spec which stops you at 17% SOC instead. With the EU spec coding, I was easily able to achieve 33 miles driving around town with the A/C off on a nice day.
The cells are made by Samsung SDI. Regarding battery degradation, my BMS reports about 1500 equivalent full charge cycles. It shows 93% state of health and 96% of the stated gross capacity. I would consider this quite good considering that it's been operated in a hot climate. The battery thermal management (R1234yf) is pretty aggressive in that it keeps the average cell temperature in the low to mid 80*F range even when the ambient is 100*F or above. The compressor kicks on while charging on a warm day, even when using the 120v/10a granny cord.
The hybrid platform is based around the ZF 8P75H transmission, which is a version of the trusty 8HP75 with the torque converter assembly removed in favor of an electric motor module which also houses an engine separating clutch. The shift from 1-2 in electric mode is often clunky and one of my main gripes about this car, but you have to understand that it's a hard thing to engineer out. First gear is very short on the ZF8 and without a spinning engine/torque converter to dampen the shock, you'll feel a stiff bump when the TCU miscalculates your driving style. Sometimes it gets it right, and it does improve as the fluid warms up. With the engine spinning this is a non-issue, and gearshifts are superb otherwise - firm and quick in sport, light and precise in hybrid.
I've been pleased with the operation of the hybrid system. With the stereo turned up, I usually can't tell when the engine has kicked on.
ENGINE
Up front you'll find the B46 (US market). It sounds like a bag of spanners, produces a very slight but noticeable vibration at idle, and was generally a major disappointment coming from owning a butter-smooth N54. However, thanks in part to the balance shaft, it smooths out quite nicely once you get moving, and it produces a sound that's easy on the ears. It's already a torquey engine, and when linked up to an electric motor, it feels almost diesel-like in its power delivery.
There are two "fun" modes: Sport and "Extraboost." In Sport, I've logged the electric motor output and it basically gives the car an extra shove until the turbo has spooled up, at which point it mostly lets off. Extraboost runs the electric motor and the engine in parallel at full output. In either mode, the instant response to the accelerator pedal greatly improves the driving experience.
It will throw you back in your seat from a dig (particularly with launch control), but once it gets up to speed you're left with the same mild disappointment that a regular 530i delivers. Oh well... at least you got the tax credit.
CHASSIS/SUSPENSION
My car has the base suspension, and 18" square 245/45 wheels were a must when I was shopping around. It's surprisingly stiff compared to what I'm used to in a "luxury" car, but I'll take it because it can handle itself quite well in the corners. Yes, seriously... it's composed, predictable, and about as playful as a 4,100lb granny hauler can be. Keep your expectations reasonable - it's no sports car - but I've been thoroughly impressed with the chassis dynamics of BMW's G chassis cars. They're down to clown. A major, major, major step up from the F10 that preceded it (I cannot stress this enough).
INTERIOR/FEATURES
The ergonomics are superb and iDrive 7 is fantastic. Being able to use the iDrive knob is great as someone who's developed that muscle memory over the years. Seats are comfortable and supportive.
My favorite feature is the complimentary lifetime remote services, which allows you to precondition the cabin from a cell phone. My BlackBerry does not support the BMW app, so in order to take advantage of this I've had to connect my Raspberry Pi to BMW's connected services and run it through there. This works great though and is a lifesaver in Arizona. I also reprogrammed the alarm button on my key to precondition the car.
The base audio system sounds decent. Good clarity, although lacking in technical capability for bass-heavy music. From what I've heard, the amplifier is a huge bottleneck with this system.
Trunk space is poor due to the high voltage battery. This is a major compromise over the 530i. Your use case will dictate whether this is a problem or not, but I've unfortunately been burned by this when trying to haul some wheels home.
I have a pretty basic spec with only the 360 camera/parking assistance package, which is nice but not a necessity. The automatic parking is nice for parallel parking, but for regular perpendicular parking it's not at all useful - a trained orangutan could probably pull it off quicker than this system can. The 360 camera is nice and it adds full-surround object tracking for side impact automatic braking/warnings. I could probably live without this package... the standard backup camera and front/rear parking sensors are likely enough for most folks.
Driving Assistance Professional is something I wish I had. I've used it in other BMWs and it's a pretty well-executed hands-on "self driving" system. If you often go on long road trips, this might be something to look for.
----------------------------
Overall, I'm happy with this car and wouldn't mind holding onto it for a while. While not super exciting, it's a nice all-rounder that can be had on the used market for dirt cheap.
