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2005 BUICK LaCROSSE: POWERTRAIN

The 2005 LaCrosse debuts with a choice of two powerful V-6 engines, with new levels of performance, efficiency, durability and quietness that put Buick's new premium midsize sedan among the leaders in its segment.

Leading the LaCrosse engine lineup is GM's new, all-aluminum 3.6L V-6 VVT (variable valve timing), marking the first application of the sophisticated global V-6 engine in a North American front-drive sedan. The 3.6L V-6 VVT is standard in the performance-oriented LaCrosse CXS.

The LaCrosse CX and CXL have as standard the newest version of GM's renowned 3800 3.8L V-6, which has long been a favorite with Buick owners. Now in Series III form, it easily outperforms the base four-cylinder engines that account for the majority of sales among competitors such as Toyota Camry and Honda Accord, according to Mark D. Hines, marketing director for Buick's midsize cars.

In fact, Hines said the 3800 delivers about 40 more horsepower and 60 additional pounds-feet of torque compared with those models, in addition to excellent fuel efficiency.

Both powerplants are mounted in a newly designed all-aluminum engine cradle and coupled to GM's proven Hydra-Matic 4T65-E electronic four-speed overdrive automatic transaxle, resulting in powertrains that deliver smooth yet responsive performance, good fuel economy and reduced overall operating expenses.

Additionally, LaCrosse has redesigned exhaust systems for even quieter performance, and a slightly larger fuel tank (17.5 gallons vs. 17.0 in the Century/Regal).

3.6L V-6 VVT - a new standard in global engine technology

As the standard engine in the performance-oriented LaCrosse CXS, the 3.6L VVT V-6 delivers an estimated 240 horsepower (179 kw) and 230 lb.-ft. (311 Nm) of torque, giving it both the competitive muscle and benchmark refinement that have become hallmark traits for Buick.

Estimated fuel economy ratings are projected to be 19 mpg city and 28 mpg highway, or 22.2 mpg combined.

As part of the new generation of flexible "high feature" GM global V-6 powerplants designed for use in premium and high-performance applications, the 3.6L V-6 VVT has dual overhead camshafts and four valves per cylinder, while using fully variable valve timing - a first for any GM V-6 engine.

The major customer benefit of continuously variable valve timing is that it enables outstanding flexibility, delivering 90 percent of the engine's peak torque where it is most useful, between 1500 rpm and 6000 rpm.

Specifically, the electronically controlled, hydraulically actuated system places a "phaser" on each camshaft. These phasers enable the rotating of each camshaft relative to the crankshaft, eliminating the "fixed" camshaft positions of most engines.

Typically, fixed camshafts dictate valve openings that are a compromise

between smooth engine idle, low-rpm torque and higher-rpm power. The phasers, which allow intake cam adjustment through 50 degrees of crankshaft rotation and 50 degrees for exhaust cam adjustment, permit variable valve timing to accommodate the often-divergent requirements for power, driveability, fuel economy and low emissions.

In addition, this cam phasing system enabled engineers to eliminate the exhaust gas recirculation (EGR) system typical to most modern engines. By closing the exhaust valves later than normal, the system forces the desired amount of exhaust gas back into the combustion chamber for more complete burning in the next combustion cycle.

Other notable engineering features of the 3.6L V-6 VVT's 60-degree design include an aluminum block and cylinder heads; aluminum pistons with floating wrist pins and piston cooling oil jets; a forged steel crankshaft with sintered, six-bolt main bearing caps; sinter-forged connecting rods; dual-stage variable intake manifold; electronic throttle control; and fully isolated cam covers along with a new structural aluminum oil pan to reduce noise, vibration and harshness.

Other features include coil-on-plug ignition and GM's Oil Life System, which informs drivers when an oil change is required.

"This all-new engine is a perfect match for the Buick LaCrosse buyer," said Timothy M. Cyrus, global V-6 chief engineer for GM Powertrain. "It delivers impressive power across a wide range of driving conditions, while being extremely smooth and quiet - all hallmarks of the Buick brand."

3800 Series III 3.8L V-6 - more power, SULEV rated

The LaCrosse CX and CXL models are powered by the newest version of one of the most proven engines in GM's lineup. Now in Series III form, the 3800 V-6 provides high levels of power and reliability, delivering an estimated 200 hp (148 kw) and 225 lb.-ft. (305 Nm) of torque - class-leading performance for a standard engine.

Fuel economy ratings of the 3800 powered LaCrosse CX and CXL are estimated at 20 mpg city and 29 mpg highway, or 23.2 mpg combined. The 3800 Series III aIso enables LaCrosse to be among the first V-6 gasoline engine powered cars to meet the Super Ultra Low Emissions Vehicle (SULEV) standard.

One of the most significant upgrades in the 3800 Series III is the adoption of electronic throttle control, which improves both engine response and fuel efficiency while reducing hardware complexity. The new throttle control system enables the engine to respond instantly to a variety of driver inputs, while always delivering seamless performance. For example, the system curtails pedal response to facilitate low-speed maneuvers, such as parking. At medium and high speeds, however, the system accentuates throttle response, delivering linear and a consistent acceleration feel .

'QuietTuning' initiatives

The 3800 Series III has also undergone major noise/vibration/harshness reduction initiatives, including a 32 percent increase in overall bending stiffness to 232 Hz, thanks to a new structural aluminum oil pan and additional bracing. The intake manifold is now made of die-cast aluminum, improving stiffness while better isolating air intake noise. All of these enhancements result in a powertrain that has improved levels of smoothness and quietness over the Series II.

In addition to a newly designed aluminum engine cradle and structural oil pan, all other engine components and systems were carefully assessed with the goal of making LaCrosse one of the quietest midsize sedans on the road, regardless of engine choice. Specific changes as part of the LaCrosse's "QuietTuning" initiatives include:

- Acoustic engine covers.
- Recalibrated engine and alternator pulleys.
- Revised power steering reservoir and lines.
- Revised torque strut bushing.
- Revised cold idle calibration (3.6L only).
- Unequal fan blade spacing (for quieter operation - 3.6L).

In addition to these initiatives, the performance-oriented LaCrosse CXS benefits from a newly engineered dual exhaust system, which includes the use of a specifically tuned Helmholtz exhaust resonator to provide a more consistent and pleasing sound quality throughout all engine rpm ranges.

This innovative device - a first for any GM vehicle - is unique because unlike conventional resonators that are usually used at the rear portion of an exhaust system, the Helmholtz resonator is mounted upstream between the engine exhaust manifold and catalytic converter.

"This device enables us to tune out the peaks of unwanted exhaust noise right up front, and provide a much better sound quality at all engine speeds," said Larry Mihalko, vehicle performance manager for LaCrosse.

In addition to the Helmholtz resonator, the CXS incorporates a new dual exhaust system with equal-length crossover pipes - a first for any Buick midsize car. This design provides equal pressure among each engine cylinder bank for even quieter performance.

4T65-E transaxle - tuned for efficiency and performance

All Buick LaCrosse sedans are equipped with GM's advanced Hydra-Matic 4T65-E four-speed electronically controlled transaxle. This transaxle has earned a reputation for outstanding shift quality, long-term reliability and contributing to excellent fuel economy.

The 4T65-E is specifically tuned for LaCrosse, depending on engine selection. The lockup clutch within the torque converter is managed by either the powertrain control module (3800 Series III), or a transmission control module (3.6L VVT), depending on function.

Major customer benefits include the use of DEXRON III fluid with a normal service life of 100,000 miles, and a multitude of safeguards, which include an automatic upshift if the driver neglects to shift out of first gear, as well as an automatic limp-home mode.
 

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Ime glad to see there useing the HFV6 in this car eventhough ime still a fan of the 3800.And with the new refinements to the older engine it seems it will be around a wile longer.Look again at the fuel economy #'s for the LARGER 3800 compaired to the newer MORE ADVANCED and SMALLER HFV6.The slower turning OHV (some would say) OLD TECH engine is more EFFICIENT!And Ille bet that spread will widen even more in real world driveing.
 

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Originally posted by 3eb@Feb 4 2004, 01:12 AM
still a 4 speed auto....what a joke
I agree. I guess GM doesn't have a "high feature" transmission for their cars. Why can you get one in a Saturn and not a Buick?

Mark
 

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cheap *******s!
I would have liked the 3.6 (maybe slightly detuned to 230hp) in the base, and a 3.6 supercharged with close t o300 hp in the ultra.
but then again, the damn car is fwd, you can't do $hit with all that power...
ALSO, A 5 SPEED AUTO!!!!!
if a damn 200 hp ford rustang v6 can have a 5sp, why can't this car (or the vette)??!?
 

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Not much. Given the torque of the engines, this setup is effective and will remain effective. While I am sure a 5spd is somewhere down the line, this package is reliable, powerful and gives good performance.

the 5spd in a mustang is a manual, right? WTF kind of arguement is that?

FWD? Yes. Where have you been. It is well known that RWD models will make their way to the GM line in a few years. It takes time. With that being said, Cadillac has had far more power than that in a FWD chassis, so...?
 

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Originally posted by redly1@Feb 4 2004, 10:58 AM
Just curious...what advantage would a 5 speed auto add to this powertrain?
How about not getting bashed by the auto reviewers for having a 4 speed & improved fuel efficiency?

Well, at least the Corvette doesn't still have a 3 speed 50 years later. :p
 

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Originally posted by sykboy@Feb 4 2004, 04:06 PM
Not much.  Given the torque of the engines, this setup is effective and will remain effective.  While I am sure a 5spd is somewhere down the line, this package is reliable, powerful and gives good performance.

the 5spd in a mustang is a manual, right?  WTF kind of arguement is that?

FWD?  Yes.  Where have you been.  It is well known that RWD models will make their way to the GM line in a few years.  It takes time.  With that being said, Cadillac has had far more power than that in a FWD chassis, so...?
guess what... FORD HAS A 5 SPEED AUTO IN THE BASE V6 MUSTANG

both camry and acord can offer 5 sp auto.
4 sp auto is '80's technology, that for sure will scare people away.
learn to read "old" when you see "proven".

and about the fwd remark... well, bother me when bmw or mb does one, then you'l have an argument :lol:
 

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I wasn't aware of that. I don't give a f'k about a Rustang, especially the secretary special V6. Wait I will check that. Ooops. Your wrong. (Rustang specs)Thought so. Perhaps you meant the next Mustang that isn't out yet. Oh and the rest of the line? No. Guess not.

I will have to say that a 5spd is immenantly necessary, however, not yet. I would also have to hope that just becuase it is a four speed now that that won't mean the 5T65E won't fit when it arrives.

On the FWD remark, it was made in light of the FACT that the move to RWD is being made, it was not a comment on which is better, there are plenty of other threads around about that. Take sometime and read some of the rest of the site if that arguement is what you are looking for. I was simply stating FWD has been the norm. I guess things should happen overnight, huh? I wish too.
 

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well, aren't both this car and the (new) rustang '05 models?

you keep saying that they need a decade to move forward... well, the cts is maybe the only sedan buit competitively, and it's here since some time allready.
competition is tough, I just say the gm should try harder, that's all, not just count on loyality or fleet sales, or morons who don't have an ideea and just go out and buy junk.
personally, I better go out and find a nice lt1 roadmaster if I want a nice large rwd car: if the market dosen't have my product for any stupid reason, I'll buy used and ultimately screw them. that should easily hold its $hit together few years untill the zeta platform hits the market and I would be again pleased by a product built seriously, not some joke
 

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Originally posted by Ming+Feb 4 2004, 11:32 AM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Ming @ Feb 4 2004, 11:32 AM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-redly1@Feb 4 2004, 10:58 AM
Just curious...what advantage would a 5 speed auto add to this powertrain?
How about not getting bashed by the auto reviewers for having a 4 speed & improved fuel efficiency?

Well, at least the Corvette doesn't still have a 3 speed 50 years later. :p [/b][/quote]
seems like a costly way to impress reviewers. Plus, it's not a free fuel efficiency increase. You're going to sacrifice some driving pleasure. Then the reviewers will be saying "seems like it's always shifting"

I think implementing technology for the sake of technology (and not practicality) is a damn bad idea
 

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a 5 spd auto would allow for better fuel economy (b/c it runs lower rpms) better performance (b/c the gear ratios allow the car to stay within its highest powerband for most of the time) and it would also make for smoother shifting. and as for thinking that pleasing auto critics/journalists isn't worth the money...believe it or not some people actually use that as a guide to what car is best for them to buy....weird huh? in other words...good reviews = better sales. and obviously that means a return to GM for the money they put into the car initially. make sense?

it's not technology for the sake of technology. it's technology for the sake of improving the car, and actually keeping up with the competition who is already ahead. why should someone settle for what is "good enough" when they can have something that most people consider better for the same price? GM can't just rest on what has worked in the past.
 

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Originally posted by johnd89@Feb 4 2004, 11:37 AM
well, aren't both this car and the (new) rustang '05 models?

you keep saying that they need a decade to move forward... well, the cts is maybe the only sedan buit competitively, and it's here since some time allready.
competition is tough, I just say the gm should try harder, that's all, not just count on loyality or fleet sales, or morons who don't have an ideea and just go out and buy junk.
personally, I better go out and find a nice lt1 roadmaster if I want a nice large rwd car: if the market dosen't have my product for any stupid reason, I'll buy used and ultimately screw them. that should easily hold its $hit together few years untill the zeta platform hits the market and I would be again pleased by a product built seriously, not some joke
I said nothing of the sort. Once agian, you are wrong.

Anyway, GM, to my knowledge, has undertaken massive product developement. Nearly the whole line has changed or will soon. Despite what you may want or think, there will still be a market for FWD luxury cars. What, because some are moving to RWD ALL have to? I do not think that is wise. If FWD cars had NO market, could understand. However, for a multitude of reasons, there is still and will still be a market for them. Every car isn't made for you. That is why there are choices. Thinking people are morons for choosing something you don't like or want? Nice. Grow up.

I find this car attractive and VERY Buick. Someone should put together some shots of the last Rivi', LeSabre, etc. I think there are definite design ques that exist across the line. Looks like it will be a successful evolution of what exists to me.
 

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I'm a diehard buick fan, how can you say that I should look elsewhere?!?dream on, I have nowhere else to look. I'll just wait longer. I have the time, but what can you do with people who don't want to wait??

gm went so deep in the mud with those premium brands (poor olds also) that it needs a REVOLUTION, not evolution. and they can do it: the proof is the cts.

I am expecting too much from gm, or they don't struggle enough?
 

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I understand the frustration. I was just starting to warm up to Olds and they got the axe. However, now that Olds is gone, Buick will gain some of what GM lost when Olds went under, I hope.

I suppose I see what you mean about being tired of waiting but I don't know if Buick will ever be what it was. Will it ever be a GSX, GN, GNX capable brand again? I don't know. I hope so. Is this the Buick you are waiting for?
 
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