Continuing My Thoughts on the Air-Cooled Engine

The other day, I introduced Part 1 of asking my husband, who drives the 911 (964C2) almost every day, what he likes about it, and now I’d like to share Part 2.

毎日のようにポルシェ 911（964C2）に乗っている夫に、何が良いのか聞いてみた【前編】

However, after finishing this part, my husband said, “I said it like that before, but the more I drive it, the more my feelings change again.” (laughs) Well, since I already wrote it, I’ll share his thoughts as they stand now.

About the Air-Cooled Engine

The 991 (964C2) Engine

You often hear things like “Air-cooled engines are different from water-cooled ones” or “Air-cooled engines are great!”, but I wondered how my husband feels about it.

He says the engine wakes up quicker than expected when you turn the key. After a brief moment of uneven idling, the revs stabilize quickly, and he thinks it’s not that different from modern cars.

Following German automotive philosophy, he doesn’t warm up the engine by idling but starts driving slowly right away to warm up the engine, transmission, and moving parts. He said, “It has enough torque and power to move a body weighing 1410kg as stated on the vehicle inspection certificate.”

Like other Porsches, the 964 responds faithfully to subtle throttle inputs. He feels once again that it’s truly a Porsche in that it moves exactly as much as you press the accelerator.

However, he honestly feels that “Although air-cooled engines are said to rev well, compared to modern Boxsters and 911s, they don’t quite match up.” Of course, this depends on individual cars and how they’ve been used, but based on his experience, modern Porsches take the lead. (This feeling is based on driving, not just revving the engine in neutral, which is influenced by flywheel weight and other factors.)

To be clear, it’s not that the engine doesn’t rev well—it does. But the latest Porsche six-cylinder engines rev even better, are more torquey, and smoother. It feels like water-cooled engines have less friction (small “rubs” and “resistance” throughout the engine) and higher compression ratios than air-cooled ones. (This is just an impression, not actual figures.)

Still, he thinks air-cooled engines are great! This was something he didn’t realize in the first few days but now says “The revving feel and torque sensation are strangely addictive.” (I still don’t quite get it myself.)

When I asked why he feels that way,

He said it’s hard to explain in words, but maybe it’s the “contradiction of a loud mechanical noise yet smooth revving” that’s addictive. The air-cooled engine isn’t quiet; you can hear the cylinder vibrations and sounds clearly outside. Despite the noisy clatter, it surprisingly revs smoothly, pulls strongly, and as the revs rise, the sound changes into a well-rounded, pleasant tone. That might be the charm.

The 991 (964C2) Engine Sound

What about the sound of the air-cooled engine?

He has no objection to the idea that “air-cooled engine sounds are great.” Even at idle, the sound is quite audible. Most of it is mechanical noise, with exhaust noise playing a smaller role. This ratio doesn’t change much even at mid to high revs, and the sound is a unique blend of combustion, moving parts, intake, and tappet noises. This analog sound is rare in modern cars and has a lot of character. People who love air-cooled engine sounds are probably drawn to this.

He also said that when comparing water-cooled and air-cooled engine sounds, it’s not easy to say one is better. Modern water-cooled Porsches and air-cooled Porsches belong to completely different sound categories.

Modern water-cooled Porsche engine sounds tend to have a larger proportion of exhaust noise compared to air-cooled ones. For example, the Boxster’s engine sound is audible, but the exhaust sound is equally or even more prominent. Some might call this “manufactured” or “artificial” sound, but it’s still a great sound. If I had to force an analogy, air-cooled engine sounds are like percussion instruments, while modern water-cooled engines are like wind instruments. Maybe that gives a rough idea.

So, regarding which engine sound is better, it’s purely a matter of personal preference and not something to judge as superior or inferior.

Fun, Comfort, and Reassurance

At this point, my husband’s impression is that “the 964 Carrera 2 is a touring machine.” He honestly says that if you want to attack winding roads like the Royu Driveway, the Boxster GTS personally offers a stronger sense of “comfort.” He attributes this to the Boxster’s mid-engine layout providing stable turn-in, and the engine’s piercing exhaust note and power delivering rapid rev increases.

On the other hand, for touring use, the 964 feels less tiring than the Boxster. (However, he hasn’t done very long trips in the 911 yet, so his impression might change later.) Although the 964 has more noise and vibration than the Boxster, the strong road contact and solid body feel probably make it feel that way. Because of that, the 911 gives a stronger sense of “reassurance.”

So, the road he most wants to drive in the 911 (964C2) is… “a country road.”

In Japan, that would be roads like the Tsumagoi Panorama Line, the Mimasaka and Manami highways in Okayama, or wide rural roads across the country. Ideally, Germany’s Romantic Road would be perfect. Fix the Tiptronic in 2nd or 3rd gear and cruise at a comfortable pace while listening to the air-cooled engine sound—it’s the best. It’s not about pushing hard but enjoying the mechanical noise as background music, maintaining a slightly brisk pace, and smoothly flowing through gentle curves one or two at a time. You consciously shift weight entering tight corners and apply traction firmly to the rear wheels to exit the corner. That’s the kind of “fun” the air-cooled 911 offers.

He’s already completely hooked on the air-cooled car (laughs). When I say I’m going shopping, he keeps saying, “Why not take the air-cooled?” But I still prefer the Panamera, and if I drive the air-cooled for more than 20 minutes, our daughters in the back seat start getting restless, so I haven’t quite reached the point of sharing the air-cooled fun with him yet… but I hope to drive it again when I get the chance.