Underbody Photos: 2012 BMW 328i

The current Car and Driver features an underbody photo of the Caddie ATS, and the resemblances are striking, right down to to the lower front strut links (instead of a single lower control arm) and the cast iron rear diff.

Is that an oxygen sensor on the tailpipe?

Nice suspension links... but apparently German Engineering consists of an entirely aerodynamically clad underside.

I sure hipe this is a long term car just for the entertainment of reading 648 flame posts :)

1. needs solid rear axle from mustang to be a real handling star
2. needs a diesel engine to get low-end torque and therefore faster acceleration

I don't think that's an O2 sensor on the tailpipe, I would guess some sort of valve that opens in "Sport mode" to make it louder or something like that.

"Nice suspension links... but apparently German Engineering consists of an entirely aerodynamically clad underside."

Unsurprisingly German cars have all the underbody aero to ensure stable cruising at very high speeds. Spoken from experience, a 3-Series is pretty quiet and rock steady cruising at a 130 mph clip. After awhile it feels like 70 mph, until you have to slow back down to 70 which then feels like 35. ;-)

@cynic783

"1. needs solid rear axle from mustang to be a real handling star
2. needs a diesel engine to get low-end torque and therefore faster acceleration"

Either my sarcasm meter is broken or something's very wrong here...

@bimmerjay - amen. My e90 was smooth as silk at 140. It was at that moment I regretted buying an e90.

@lvgti

My guess is that it's an electronically-controlled butterfly valve to enable more exhaust flow under higher loads. Look at the "stub" at the opposite end of this electrical device. Nice idea.

A DIY oil change looks like an all day job.

All that cladding--I hope it won't overheat during rush hour in the summer with 100+ degree heat. Overheating will cook the turbo.

expolrerx4, ther is a very convenient flap that you open to drain oil pan.

Super easy while preserving the aerodynamics...

Looks absolutely gorgeous to me. I've had one 3 series in my life and I always refer to it when complaining about a car's build quality. It ruined me.

My old 2008 Jetta had a few clads like those on the BMW. Anyother car of it's class had it. And the ride was quite good for such a car when over 100mph

I'd expect to see more and more vehicles with nearly full underbodys to reduce drag and improve fuel economy. BMW went a step further and added some to the rear control arms too! Looks like the central air scoop is to cool the transmission. Doing an oil change will not be fun.

Check out the size of that exhaust! I looks to be about 60mm diameter or so which is pretty beefy straight from the factory. The muffler has that butterfly valve to keep it quiet at low loads and open up when power is required. Corvetes have the same thing. Many other cars do too, but it's an internally spring loaded valve internal to the muffler. Like the Nissan Maxima's somewhere around the mid-2000s had that algon with the Evo.

"Unsurprisingly German cars have all the underbody aero to ensure stable cruising at very high speeds. "

Even my 1995 ti has an underbody tray as well as the small wind deflectors in front of each wheel, an aerodynamic detail also used by Mazda on my MS3. Both cars are utterly composed at 130 mph, although the ti is pretty much maxed out at that relatively tame speed.

"The current Car and Driver features an underbody photo of the Caddie ATS, and the resemblances are striking, right down to to the lower front strut links (instead of a single lower control arm) and the cast iron rear diff."

Exactly right - cast iron diff has higher weight, but lower thermal expansion and less bearing preload - nice engineering detail.

As for the cladding, it's exactly right - much more stable even at highway speeds, in a crosswind. Also the car is much quieter with the underbody cladding. Lots of what people had identified as road noise coming up through the tires turns out to be wind noise coming from all the aerodynamically dirty stuff down there. So it's a cheap and zero-weight route to a quieter car.

And yeah, German cars tend to be ahead of the curve on this - my wife's 2000 Passat wagon had the full belly pan in front and the little pants/deflectors to smooth airflow around the rear wheels. I noticed over time (got rid of that car less than 2 years ago w/162,000 northeastern miles on it) that underbody hardware was much less corroded due to the belly pan, compared with other cars with that many miles.

I don’t know about you guys, but I’d rather see a suspension walk-around in a suburban driveway than the one dimensional underbody photos on the fancy new lift we’ve been getting lately. So much detail, that I care about, has been lost.

What gives, Edmunds?

BMW. Still a huge fan. Just hate how they cheap out on not having a spare tire. I always seem to get a flat at the worst possible time.
Run Flats suck. I changed to regular tires and put a spare tire in the trunk.
Good thing I had a spare because I got a nail in my BMW summer tires.
Faster and cheaper to change tire then to call tow truck and repair tire with screw in it later.

@davantriv: "We'll have a full suspension walkaround for you later, but for now just enjoy this look at the latest in German engineering."

BMW has always been good about having easy access flaps for the oil drain plug. This car is no different, you can see the flap in the middle of the front pan in several of the pictures.