Long-Term Road Tests

"Engines such as the current BMW M5/M6 V10 are not known for their glorious sounds, despite being exceptionally smooth. "
  
"I have never read any criticism of the sound of a BMW engine."
 
The M5s V10 does sound a bit odd at idle as its almost diesel like in character. Once you start the drive and let the V10 fill its lungs, let me just say its a sound that you will never forget.
 
http://youtube.com/watch?v=3R6v4Bm2ecI

"Engines such as the current BMW M5/M6 V10 are not known for their glorious sounds, despite being exceptionally smooth. "
 
I have never read any criticism of the sound of a BMW engine.
 
Roughness is not the same as lack of willingness to rev. Most older pushrod engines like the 3800 do not rev freely and thus they give the impression they are straining as they approach the redline. This has nothing to do with NVH or the ambiguous "roughness" that people keep referencing. Some OHV engines make more noise near redline than some OHC engines but as with any vice you can control it with technology and engineering refinements. LEt's not forget the LS7 redlines at 7000rpm and revs freely due to exotic materials and other things. It makes sweet noises as well.

One thing I've noticed when comparing my Aura XR's 252 hp 3.6 to my previous Grand Prix GT's 200 hp 3.8...the Grand Prix FELT faster, even if it wasn't. If the Aura was mated to a better, more responsive transmission I might feel differently.

The OHV engine in the Aura XE has become my favorite feature of the car. I just admire its performance/economy ratio. I'm getting better mileage than I expected when I bought the car, but the performance is right in line with what I demand. And to think, I had almost bought into the hype about OHV's being somehow "outdated" tech...
 
As for NVH, the engine is butter-smooth at high RPM, but I'm sure the mounts have a lot to do with that. The [lack of] engine note is the only disappointment: when you floor it, all you hear in the interior is an airflow-like "whoosh" sound. I'm not sure if it sounds all that great from the outside...

Low reciprocating mass = smoother operation. Engines with a pushrod/ohv valvetrain have higher reciprocating mass, so they are inherently rougher than ohc engines. This roughness is especially noticeable at higher rpm.
 
If you don't notice it in certain applications, it's because it's been masked through things like improved (i.e. tunable or liquid-filled) engine mounts. These are very nice tools for masking the inherent roughness of the ohv layout, but open the hood and you can still hear it when the engine is revved.

I think you are trying to classify engine noise into the black and white world of "anti american/pro-import bias".
 
Engines such as the current BMW M5/M6 V10 are not known for their glorious sounds, despite being exceptionally smooth.
 
But the V8 version (the 4/5ths of the V10) in the M3 is praised.
 
Some people think the VQ35 is obnoxious sounding...I think it sounds good in it's current and previous iteration, but was tiresome to listen to all the time. It doesnt' change it's tone, it just gets louder. But in it's older iteration, it was a harsher engine (i.e pre 2007). More vibration, more noise outside of it's tuned exhaust/intake sound.
 
I've driven my fair number of american cars, including a few 3800s and my just-traded-in Saturn Ion, mustangs and mustang gts, Dodge rams and Ford Explorers. I have not yet driven the Aura or Malibu, which you have commented on.
 
In past experiences, I did not find an american 4-cylinder or 6-cylinder that had the smooth linear power of the foreign competition. Their engines were less refined, more rackety, and less pleasing to the ear. So I categorize that in the subjective (sound) and the objective (vibration/harshness/smoothness/etc.).
 
I'll turn the tables though...I've never driven a foreign V8 that I thought was as good as one of the Big 3's...I haven't driven some of the foreign V8s from BMW or Mercedes, but I didn't care for the Toyota I-Force V8 compared to the Chevy or Ford version.
 
Some of this is very subjective, but I think you can somewhat quantify smoothness/vibration/harshness. And I think the american companies, in the 80s, 90's and early 2000s did not make the best 4s and 6s.
 
Of course, I'm not backed up by years of journalism across an entire industry, sales trends showing a displacement away from 4 and 6 cyl models, and an appreciation for 8-cyl SUVs and trucks in the 90s....
 
Joe

"1487 - There is a difference between noise, lack of refinement, and a pleasing engine sound. "
 
Its all subjective. No one has a problem with the sound og OHV engines when talking about V8s. Naturally since import companies have always used OHC engines their engine sounds have become what is considered acceptable or even beautiful. Anything that differs (i.e. "low tech" OHV engines) makes unpleasing sounds according to the press.
 
"I dont think that the 3800 was really "loud" it just sounded a bit harsh/rough. It wasnt particularly smooth nor refined."
 
I read this a lot but I don't know what it's based on. OHV engines do not like to bounce of the rev limiter- that's just the way they work. The 3800 exhibited no unruly NVH characteristics at any speed. Sure the growl near redline is more throaty than a Toyota DOHC V6 but the engine is not unrefined or harsh. For an engine to be harsh or rough (in my book) there would have to be some sort of vibration or racket when pushed. Modern iterations of the 3800 do not have this issue. Same goes for GM's other OHV engines that I have sampled.

Jstandefer: I guess I'm the guy who prefers the Aura styling to the Malibu. I'm not crazy about the Malibu's more formal roofline, and I definitely don't like the rear quarter. Overall, I prefer the Aura's sporty cues, which are lifted verbatim from the Opel Vectra.
 
Don't get me wrong, overall I think GM hit it out of the park with the Malibu. I even liked the Impala LT I rented recently; zero interior charisma, but it soaked up some horrible road conditions without ever losing its composure. If the Malibu can do that, then its attractive styling should really make it desirable.

Using manual mode can maximize fuel economy, it's not just for holding gears, you can upshift and save gas.

"Personally, I dont find the engine all that quiet. I'm sure the Camry has a much more hushed engine. For all the hype over DOHC engines I dont find the 3.6L to be much quieter than the 3800 or the 3.4L in the Alero. Its freer revving but not all that quiet under hard acceleration. I'm sure a Toyota owner would be horrified at the amount of racket coming from the Aura's engine bay"
 
The Toyota V6 may be quieter (IDK) but its probably due to more sound insulation rather than greater refinement. Toyota isolation is gross!
 
I dont think that the 3800 was really "loud" it just sounded a bit harsh/rough. It wasnt particularly smooth nor refined. It wasnt fond of reving either as it ran out of breath in the upper regions of the tach. On the contrary it was very reliable, fuel efficient and provided good low end punch.
 
A lot of folks here seem to think refinement and low engine noise are the same thing when its not. For example a Honda Civic Si engine is a very loud (WOT), refined piece BUT makes great noises, and its smooth at nearly any RPM.
 
The same could be said for the 3.2 SOHC VTEC V6 (J32A) in my 03 Acura CL-S 6MT. Its butter smooth, loves to run to redline anytime and sounds great while doing so. It also makes VERY good low/midrange torque while providing that signature VTEC top end. I believe the stats were 260hp and 232lbft of torque, that latter which peaked for a couple thousand RPM.
 
My point is just because an engine is loud or audible doesnt mean it isnt refined. The quality of the sound is the determining factor.

We went to the Saturn dealership to look at the Astra, but we were quickly disappointed by that car... anyway, we decided to look at the Aura. We drove an XR 3.6 with all the options, and we were generally impressed with it. I found the interior to be of good quality materials, but fit and finish could use some attention. I was very impressed with the engine's feel, particularly the aggressive but refined growl when you get on it. But we looked at another car immediately after that caused us to cross the Aura off our list...
 
Knowing the numerous similarities, we headed over the Chevy dealership and was blown away by the Malibu. I crossed GM off of my list of potential vehicles many, many years ago, but the Malibu has really made me believe again. It was basically the same as the Aura, but higher quality and a bit more daring in design.
 
We did have a few gripes with both the Aura and Malibu. The biggest one, for us, was the use of a fabric mesh as the deflector for the moonroof. Yes, it does do a good job of diffusing incoming air, but highway speed wind howls like you wouldn't believe through that mesh. We also didn't care for the central front cup holders... a bit on the small side and a bit shallow (which is sad because the cup holders in our significantly smaller Miata are large and deep). The cup holders we could learn to live with. The moonroof could be a deal breaker (we have two convertibles also, so a moonroof is a requirement in our enclosed cars).
 
Anyway... Saturn should really update the Aura to match the Malibu. Unless the styling of the Aura really appeals to someone, the Malibu is the better car to get.

I love the engine and how quiet it is at cruise. I agree about the dedicated sport mode. I also agree that drive is too sluggish to downshift. I really think that reprogramming it would not really affect mileage all that much.
 
I am curious to see how the 2.4/6 speed dynamics are. That combo will definitely need quicker response.
 
The quiet engine helps to make my spouse fall asleep quicker, so I can make better time on drives :)

did the steering ever get fixed?
 
and Joe said this car had too much power. Ohh the head hurts.
 
I was only half joking in my previous comment.
 
The engine noise one is low on my list of pet peeves.
 
higher up, is when people complain about a soft suspesnion lacking a feeling of being in control and connected to the road.
 
But give them a stiffer suspension to fix the road feel/handling, and they complain the ride is too harsh.

stov001- I agree. Many cars used to have dedicated "sport" modes without manual gates. However they are hard to find in regular affordable cars due to the proliferation of manumatics. With gas prices so high, I leave my car in automatic most of the time to maximize economy.
 
The 3.6L is unique in that it has the same robust torque characteristics as the 12 valve 3800. For a multivalve engine, it produces lots of low end torque while still maintaining the high RPM zest inherent to 4 valve per cylinder heads. It has a beefy exhaust soundtrack that's authoritative without being obnoxious like some VQ variants. In contrast, GM's 3.9L 12 valve V6 doesn't have the same high rpm kick has the 3.6 but is no less refined or noisy at WOT. That engine has one hell of a midrange even if it's overlooked. When GM hooks the sixspeed up to that engine, it'll perform even better a return excellent MPG due to it's AFM.

I like the idea of sport shift mode rather than manual. Unless you're using a great automated-manual, manual shifting an automatic by paddles just doesn't make much sense. Then manufacturers could keep the normal drive mode tuned for efficiency and keeping sport mode for hills and empty roads. Manual shifting an automatic-equipped family hauler just seems pointless.

Ugh I hate the engine bays in new cars....pop the hood and you see.....PLASTIC! Taking plastic covers off of batteries, etc, in cold weather is a pain.

"I think you just made my day by saying that :) "
 
I aim to please.
 
THere are two things DOHC engines can do that OHVs GENERALLY cannot: generate a lot of hp/l and rev freely to much higher redline. That's about it. There is no more NVH from a modern OHV engine than from a DOHC engine. Technological advancements and improved sound deadening mean that today's OHV engines sound just as distant as a good OHC motor. I've driven the Alero, Grand Am, Impala, Intrigue and Lacrosse with pushrod motors and you dont feel anything in terms of vibration during hard acceleration. Often car mags have made the excuse that the sound is "poor quality" when knocking OHV engines even if the noise levels are low.

1487 - There is a difference between noise, lack of refinement, and a pleasing engine sound.
 
Lexus tunes it all out, and the critics complain about the isolation (those who don't like isolation).
 
BMW's inline sixes have a glorious sound, but most are now muted, which the critics don't like because it should be set free...
 
Now the Aura has a really nice engine note (according to this poster) which is quiet except when the throttle is applied (I'm guessing Saturn tuned the intake sound). And it gets praised.
 
But you are not happy. Are you?
 
Joe

prndlol -
 
He said he formed his opinion over miles and miles of driving, and then taking it out on an early morning run outside of the city he really came to appreciate the engine. Maybe in those miles and miles, he didn't have an opportunity to actually let it run the gears (i.e. a 0 to high speed run in one go).
 
1487 - Some people are a little too sensitive? Wow. I think you just made my day by saying that :)
 
Regarding DOHC and engine noise....I don't think I've ever heard, specifically, of DOHC engine design having more or less engine noise than others. I believe they are mostly known for being more eager to run at higher revs and providing a broader overall powerband (due to utilizing multiple camshaft profiles as opposed to one). I think alot of the DOHC engines, historically, have been smoother revving and therefore less noisy/rackety and less likely to contribute to NVH. But I think that was also a function of engine tuning/engine architecture and even the design of things like sound deadening and engine mounts.
 
My DOHC 2.0 liter is very loud, but if I turned up the stereo and asked my passenger to tell me, without looking, what rpm the engine was at they probably wouldn't be able to tell. There's no noticeable vibration from it running at 6000 or 7000 rpms. Just sound.
 
Joe

as OPfreak suggested, I thought quietness was a good thing. 10 years ago most vehicles that lacked a Toyota or Honda badge were derided for lacking refinement as it pertains to engine noise. Now the Aura is TOO quiet. I do indeed feel sorry for any engineers working on the next generation Aura- how do you please the critics?