I agree that American-designed four-cylinders leave a lot to be desired in the smoothness and refinement, but disagree that the GM Quad-Four used in the Malibu and Aura is an exeption. The Malibu/Aura, more or less twins on the same platform, are nice cars, no question about it (and among the few domestics I would consider owning). But, on the last Aura XE I drove, I was not particularly impressed with the four's smoothness or noise level (the Quad Four has been noted for roughness)....I would probably get a V6 if I had either a Malibu or Aura, though the V6 models have stiffer underpinnings that ride a little rougher, which I don't like.

Another four that is not particularly smooth or quiet under load is the Subaru boxer flat-four. Subaru flat-fours, despite slick advertising to the contrary, have always had a somewhat rough, grating sound and vibes when revved, though the newer ones are MUCH quieter than those of decades ago, which sounded almost like lawn mowers. I like the basic design, however, because it works superbly well with AWD, and is easy to service and work on.

I can't comment a lot about Volvo fours (the thread topic), because my experience with them is rather limited. I did, however, drive a C30 recently, with its 2.5L in-line 5, and it seemed reasonably refined.

 

Comparing "degrees of coarseness" with 4 bangers is exactly the point I was trying to make, they do not compare to the smoothness and power delivery of the best sixs and eights.

Note: What you did not drive is the latest revised version of the 4 cylinder in the Malibu, it's not the piece of crap quad 4 thankfully. The revisions addressing noise, vibration and harshness included different motor mounts, insulation plus adding a 6 speed auto tranny were implemented in late 2008. Obviously everybody agreed that the old quad 4 was not acceptable and needed to be changed.

I agree that Subaru 4 cylinders are not especially pleasant sounding, 2 close family members own them and I've driven several.

 

btw - Forum members, in your opinion who's building the most refined/smooth high performance 4 cylinder engines in the US market today?

 

The new Saturn Aura XE (the same car, mechanically, as the Malibu) that I drove a few months ago at someone's request (I did not write a formal review of it) had a four that was reasonably refined, but noise and vibration were still much more noticeable than with the GM 3.5 or 3.6L V6s. (it did have the 6-speed automatic, as I remember it).


They still are not Honda or Toyota-smooth, but are FAR more refined than years ago. Like I noted above, I can remember some Subaru boxer-fours from the 1980's that sounded and vibrated like lawn-mower engines. The Subie flat-fours and sixes, however, with their low center of gravity, light weight, and rear-pointing output shaft/flywheel, fit extremely well with Subaru's simple, superb AWD systems. There's no better inexpensive AWD powertrain on the market, IMO...especially under 35K.

 

For everything combined....refinement, smoothness, power, economy flexibility, and overall driving pleasure, IMO, the best four-cylinder engine is the VW/Audi 2.0 Turbo, especially hooked to the superb DSG/S-Tronic transmission (which is becoming harder and harder to find, as I've noted in reviews). The Subaru STI and Mitsubishi Evo turbo fours make more power, but not that much more (I've said repeatedly that I think the torque on the VW/Audi 2.0T is underrated). Hyundai has a new 2.0T in the Genesis coupe, but I have not sampled it, and cannot directly comment on it....the Genesis coupe I reviewed was a 3.8 V6.

But, in general, across the board, Honda/Acura and Toyota generally do the best job putting smoothness and refinement into ordinary bread-and-butter in-line fours. My main complaint, though, with VTEC Honda fours (and some Toyota VTEC fours as well), is that the torque curve is too peaky.......too many RPM's (IMO) are needed for good response, and, even then, max torque at high RPM's does not equal the HP figure. That is definitely NOT the case with the VW/Audi 2.0T.

One exception, however, is the Acura in-line turbo four used on the RDX......the first Honda/Acura factory-turbo four in the American market. It provides strong torque at comparatively low RPMs, without the super-high RPMs needed for other Honda-designed fours. The in-line four used in the Honda Element/CR-V is also another exception. Its max-torque figure equals the HP figure, even without a turbo.

 

Sounds like Volvo is going back to its roots. Anyone remember the Volvo 240GL?

 

I do, my brother had one for a little while, truly a durable tank.