Really I suppose this all started far prior to my M8... about 7 years ago, I got a BMW X6. This was my first real step above an entry-level level luxury car. I happened to also have a 4 series GC at the time; the 4 series was great and for a guy that tends to swap out cars often, it was the only BMW lease (out of 7 in as many years) that I kept through to lease-end, however, highway cruising in that generation just couldn't compare to smooth ride and sound isolation I experienced with my X6.
Another year or so went by and the kids were growing so I needed a car with 3 rows. The X7 wasn't yet available and I wasn't a fan of other options so picked up an X5 35d with the tiny third row when my 4 series lease was up... it did its job, but it was missing the DHP, multi-contour seats, and individual full leather, so it was a bit of a disappointment when directly compared to the X6 I still had at the time. I ended up getting rid of the X6 anyway since I didn't like having 2 SUVs and needed the 3rd row in my X5 and decided to treat myself to an F80 M3 as it was basically a second car at the time. I then upgraded my X5 to the X7 as soon as I could, and I had what felt like the perfect pairing at the time. The G07 X7 was just as smooth and quiet as my X6, and the F80 was fast, fun, and still practical being able to fit all 5 of us in a pinch.
I went along for a good year with that combo, then got into an accident with the X7. I had a rental, but of course I didn't really want to drive that so the M3 became our main family/trip hauler for about a month. Those F80 M3s with full leather were certainly a step up from an F3x, but it wasn't the car I wanted to be on the highway with 3 kids for over an hour. After I noticed this, I realized it wasn't even the car I wanted to be in on the highway by myself for over an hour. Once I got my X7 back, I immediately started looking toward an M550, M5, 8 series, etc. (along with the other German equivalents), to replace the M3... something that could still have a bit of a fun factor with performance, but more importantly be a good highway cruiser for myself that could fit 2+1 small child as the older kids growing meant we weren't going to try to squeeze them into the second car if we were all heading out. I figured I could get a way with a 2+2 coupe or another GC if it tickled my fancy since I didn't have to worry about it fitting 5. The G82 wasn't out yet and I was a bit skeptical of how it would be on the highway with my F80 experience anyway, so I decided not to wait and unload my M3 a little early. I kept hearing of this magical "trunk cash" on the 8 series, so I decided to look around. I was able to get out of my F80 M3 and into the F92 M8 at about the same payment (my F80 payment for inflated a bit because I rolled some negative equity into it).
The M8 certainly ticked all the boxes I was looking for, but something about it made me get bored of it quicker than any other BMW I had owned. It's possible it was just due to me getting a base car (without full leather) in Alpine White, possible it was a little too numb compared to the M3 so I couldn't feel the power the same, but what should have been my dream car just had me feeling a bit "bleh" within about 9 months. It wasn't horrible by any means as it still ticked all the boxes... but I started looking around last summer since my crazy deal at the end of 2020 in combination with the continuing supply chain issues already gave a bunch of positive equity. I didn't put a lot of time into it and the winter approached quickly so I decided to wait until the Spring, at which time I realized my X7 was going to be well over mileage by lease end and I wanted to replace it with a pre-LCI version so ended up ordering that car in April and taking Delivery on 5/2.
During the delivery of my X7, I let my CA know I was in the market for something new to replace the M8. At this point, my little one had a growth spurt and was complaining of the room in the back of the M8 Coupe, she actually only rode in the back of that car twice in the last two months as she was just big enough to get away with riding up front now. This really meant the car that was mainly my daily commuter that could also drop my daughter off at school in the morning, didn't necessarily need 4 seats (or if it did, shouldn't be in a 2+2 configuration), so my potential replacements really grew and I had to weigh the balances between fun and practicality. I thought about the i4 pretty quickly since I knew the new G2x/G8x cars were pretty quiet by this time and looked around in May/June, but pretty much gave up since I wasn't going to get anything without paying markup, not having the right options, or waiting. I still went to a UDE in July so got to drive the car on the autocross course along with a street drive. I certainly wasn't blown away by any means, but I was content that it could still be a viable replacement if I could ever get my hands on one. Last month I included the Z4 into my search and made some good progress a couple weeks ago. I was excited about getting back to more of a driver's car, but would have likely been annoyed that it wasn't a good highway cruiser again. Most of the Z4sI really wanted were not going to be available for delivery until October either so I gave up knowing that come the fall, I wouldn't be too excited about a roadster in PA. Anyway... I was heading on vacation and asked all the CAs I was working with to close the leads and leave me alone, figuring I might just wait until next spring to look around again as I certainly wasn't "settling" by keeping my M8.
The last few days have been a bit hectic... I came back from my trip on 7/30, got a dog on 7/31 (our previous pup fell ill over the 15 months and we had to say goodbye a couple of weeks ago), and I then received a call from my normal CA on 8/1 that they just got an i4 M50 off the truck that someone cancelled their delivery on. He sent me the build sheet Monday afternoon, they charged it during the day yesterday, and I took delivery last night!
Now for an actual comparison as the title suggests... I drove down with the M8 on a low-traffic highway enjoying the peaceful cruising I could achieve in that car. I started to worry if the i4 could compare with how quiet the cabin could be and decided to take some readings so I would at least have an objective point to compare against. I averaged 66.9 dB in the M8 while cruising at 75 MPH on a smooth road with the engine in comfort and exhaust sound off (74.8 dB in Sport+ with exhaust on if you're curious). That 66.9 dB reading was also coasting downhill for about 10 seconds, so basically just a road/wind noise measurement. I was happy to see on the way back, the i4 was averaging 63.4 dB in about the same spot.
In terms of power, the instant torque is what it is, 0-30 is pretty intoxicating, as is 60-70, 100-110, etc.., but you could certainly tell the difference in the power-to-weight ratio when you go beyond that as you see with the numbers. 0-60 might feel quicker than the numbers suggest as many mention due to that initial torque, but it's certainly not even close to what the M8 can deliver as it just can't pull as hard toward the top end. Obviously I knew this getting into it, but I would say it's still satisfying, just in a different way (likely a safer way as I don't feel the desire push that top end like I did in the M8).
The handling was a nice surprise for my drive one the way home. Obviously the M8 is a pretty heavy car with a bit of understeer. I certainly felt that understeer in the autocross course at the UDE with the i4 M50 (especially with regenerative braking off), but for real every day driving with on-ramps/off-ramps, etc., I felt like I could push it pretty hard and still maintain some limited body roll and good control. It has all-seasons on it that are brand new, so I didn't really want to push it too hard, but I felt they would at least by the main limiting factor. The weight of the car makes it feel just as stable as the M8 at those... higher... cruising speeds as well.
Overall, I'm happy with the switch. I have an EA fast charging station within 2 miles of my house, so I should have fun playing around in the upcoming weeks. I used it once this morning and went from 50-80% within 19 minutes.