CowboyRL

Seriously? Acura is now pulling a "Nissan". I used to own a Maxima back in the day, and I remember how they made the Altima pretty much the same thing as the Maxima but less expensive. Now here I am in an Acura showroom to find a TL with the SH-AWD (which is one of the main differentiating factors of these two vehicles) Is this the end of the RL? The service guy said something about how Acura is/was trying to bump up the RL to some super 80K vehicle.......

**before anyone gets on me for not reading prior posts, I dont remember reading this discussion. **

TampaRLX-SH

Yes, the TL SHAWD model overlaps the RL more than before. But the RL was released in 2004, when the TL was in it's previous generation. It is the purpose of a flagship to introduce features and technology that trickles down the product line.

The RL cycle has been longer, and this generation is no exception. But expect the next gen RL to supersede the TL by a larger margin.

But look at the bigger picture. SHAWD has been integrated into all Acura models now except the TSX. The RL introduced SHAWD into the brand, and has done it's job bringing it to the brand, nearly in it's entirety.

I believe the SHAWD of the RL is still more sophisticated than the other versions in other models until the TL SHAWD launch. Though the TL version has now included this, the RL was the only model that utilized a planetary gear to over accelerate the outer rear wheel to simulate the yaw effect of RWD oversteer.

Yes, the TL SHAWD does overlap many of the RLs features and capabilities (and is nearly priced for what an RL can be purchased). But the RL has been doing it for 5 years already.

db22

The biggest mistake that people make is that they think that the RL and the TL are similar vehicles. I am not going to explain the difference on this forum because most of us in this forum paid more for the RL for a reason and the TL lurkers are trying to tell themselves that they really got an RL for the price of a TL. I have driven the new TL and I would still have my 05 RL instead of the new TL.

rockstar143

iTrader: (6)

If SHAWD is all they were looking for, then for all practical purposes that is exactly what they did.
The TL is not the RL...I don't think anyone contests that. If I had my choice, price being the same, I would probably still opt for the TL because I like the styling a bit better. You don't have to have that superiority complex tone to get that point across.

db22

Acura should give you a TL. You maybe the only person out there who not only likes the TL styling but also prefers the TL over the RL.

CowboyRL

Tampa: You make a lot of very good points that I completely agree with. I'm just protective of my RL and its features. :-)

037

when the price was the same, I chose the RL over TL.

Chas2

Actually descriptions of the TL SH-AWD do not include the so called acceleration device or the third planetary gea rset that Tampa describes above. While the RL can vary rear overdrive speed, the TL rear over drive remains fixed at 1.7%, just like every other SH-AWD implementation in the Acura line...

...which prompted my question a couple of years ago, as to whether the fixed rear over drive speed is v 2.0 of SH-AWD, (simpler, lighter, more reliable in that there is one less component to mess with) or whether the third planetary gear set is truly the shiznit as neuronbob likes to say.

TampaRLX-SH

Chas, have you found Honda's official tech spec on the TL's SHAWD? I saw several non Honda references, and they were conflicting. One did mention the planetary gear, but it may have been copied or referencing the RLs set up. I am searching for Honda's detailed specs to clarify.

As far as SHAWD 'lite', I believe that was the case when it was introduced on the MDX and RDX. I wonder if being CUVs and a higher center of gravity, the planetary gear may not work with those vehicle's dynamics. That yaw 'kick' that the RL gets might make a CUV unstable in a turn with the additional height. The TL being closer to the the RL in dimensions, weight and platform may be able to accommodate the RL's SHAWD version. Just my guess.

037

for some stupid reason I always thought that SH-AWD was the same in every car, otherwise it's just plain AWD and that'd be stupid.

Chas2

Here is my source.
It is a very different description than the RL, and the constant 1.7% over driven rear wheels is consistent with the two CUV's.

http://www.hondanews.com/categories/735/releases/5197

SH-AWD® System Layout
The TL SH-AWD® is a full-time all-wheel-drive system that requires no driver interaction or monitoring. A torque-transfer unit is bolted directly to the front-mounted transaxle. The torque-transfer unit receives torque from a helical gear that is attached to the front differential's ring gear, and a short horizontal shaft and hypoid gear set within the torque-transfer unit's case send power to the rear propeller shaft, which in turn transfers power to the rear drive unit.The TL SH-AWD® rear drive unit is constantly overdriven by 1.7-percent and the resulting overdrive effect is regulated by left and right electromagnetic clutch packs which independently control the power delivered to each rear wheel.


http://www.hondanews.com/categories/735/releases/5197

23109VC

i've driven the new TL, and have an 06 RL. the 2nd gen RL is a nicer more upscale/luxurious car than the TL. that being said, the new TL is a very nice car. it feels more "modern" and sportier.. they are similar in size and features...but if you drive them, the RL still feels more expensive and luxurious. sitting in the two cars, opeinign anc closing doors, the feel of the car as it drives - the TL is nice, the RL is nicer.

the great thinga bout an RL is that you can pickup a CPO one for half what they want for a new TL.

in a few years, maybe i"d consider a CPO TL SH-AWD...

as Tampa has said - they are NOT the same car and have very substantial differences...

037

so, in plain english, does the TL have a differently behaving SH-AWD was the RL?

TampaRLX-SH

Gotcha Chas. Good find. Then in fact the planetary gear to dynamically over-accelerate the outer real wheel on the RL is in fact, unique to the RL. Though similar on the TL it is over-accelerated at a constant 1.7 %.

I guess we have Super Duper Handling - AWD!

037

what % range can RL over accelerate is the better question.

It would be lame if the TL has a more advanced system.

I know some software mods were done for the RL in 2.5G so maybe they just copied whatever the current TL had...

TampaRLX-SH

*sigh* 5.7%

Even if they were the same, the cars ARE different. They perform to programming logic and sensor reactions because they ARE different. The RL's yaw sensors will trigger SHAWD reaction differently than a TL. They have different mass and that will cause different behavior in the turning conditions as the geometry is different. Copy RL programming logic into a TL (if even possible) could likely plow it into a concrete wall. Likewise why it is different for and MDX, RDX or even the MMC RL (with changed suspension geometry, wheels, engine HP and torque and sensor thresholds).

Other than playing a pissing match with TL SHAWD owners, this is just trivial.

For what is worth:

Acura RL's exclusively contain a third planetary gear set and clutch pack that are packaged into a so called "Acceleration Device", which is bolted in front of one the rear differential unit[2].

As of early 2009, SH-AWD has been implemented by Acura in two functionally similar, but mechanically different configurations, with and without Acceleration Device. The more complex SH-AWD version uses the Acceleration Device[13] and can be found in:

2005–2008 Acura RL Sedan
2009-TBD Mid-Model Change Acura RL Sedan

The less complex version of SH-AWD omits the Acceleration Device[12][16][17] and can be found in:

2007-TBD Acura RDX CUV
2007-TBD Acura MDX SUV
2009-TBD Acura TL SH-AWD Sedan

The Acceleration Device allows the rear wheels to be variably overdriven with respect to the speed of the front wheels up to 5.7%.[13][16][17] The Acceleration Device in the Acura RL is positioned in front of the rear differential. During normal steady state driving, the Acceleration Device input shaft (from the engine) and output shaft (to the rear differential) spin at almost equal speeds. In a cornering situation, the output shaft spins up to 5.7% faster than the input shaft, effectively speeding up the rear wheels. The electromagnetic clutch packs, based on sensor inputs, will vary the torque sent to the rear differential from side to side providing constant and dynamic balancing of the car handling characteristics.[13]

The SH-AWD configuration with no acceleration device is simpler and overdrives the rear wheels at a constant 1.7% with respect to the speed of the front wheels[12][16][17].

The Acceleration Device was first introduced in the flagship Acura RL sedan, and continues in the MMC Acura RL sedan. This more complex configuration appears to be unique among the SH-AWD equipped Acuras. This more complex RL configuration could be considered an exclusive flagship vehicle feature, and not specified for vehicles with lower price points. The later SH-AWD configuration without the Acceleration Device could just be a simpler and less sophisticated version due to vehicle dynamics and price points, or it could represent a more refined, less complex and inherently more reliable, new standard SH-AWD configuration. The rationale for the two distinct configurations has not been publicized by Acura.

http://en.wikipedia.org/wiki/SH-AWD

Chas2

If it is worth anything, I wrote much of the SH-AWD entry in Wikipedia some time ago, as well as enhancing much of the Acura RL Wiki. A lot of stuff got canned because it carried detailed wheel and tire data, and other "tuner" mods, so was considered out of scope. It was meant to be a more cohesive compilation of the info on Acurazine, backed up, as much as possible with data from manufacturers...oh well...we have something better, bob's garage section!

TampaRLX-SH

I knew that Wiki sounded researched and intelligent!

I hereby nominate WikiChas to be purveyor of all SHAWD specifications!

rockstar143

iTrader: (6)

Hmmm...well, maybe I would have to reconsider then. I DID notice some CPO used 05 and up RL's on the lot that were actually relatively affordable for what they offer. Maybe I WOULD prefer the more sophisticated AWD for half the price, plus the more luxurious feel. Maybe my next move. Get that and then make it look the way I want.

My comment was not to stir crap, it just annoys me when the tone gets snobby about a car being better than another as if the person is classier because they can afford a more expensive car. I moved on from an RSX and I try and maintain my humbleness even though I think the TL is superior to it.

Off to prepare for the PACMAN fight...have a great night, all!

neuronbob

And +1 to everyone who recognizes the difference between the TL and RL. Acura has done an awful job marketing the RL and telling why it is worth more than the TL. The interior of the new TL is a step above the old TL to be sure, but it is no RL. "I know the RL.....and TL, you are NOT an RL.

037

Tampa, thank you for that huge post.

In essense, the bottom line is this:

09 TL-AWD has a constant 1.7% over drive on rear wheels when required.

RL has a variable up to 5.7% power shift.

Was that so hard? I hate over complications!

TampaRLX-SH

I believe Google Search functionality is the same for everyone.

TampaRLX-SH

Interesting....the last post was deleted.

Without much thought, it spoke so clearly.

MIKEYDRED

Ther RL started this mess with the headlights not lining up with the grill IMHO the TL does look better than the RL, better seats (SH_AWD Tech) and better tech for now. Obviously the next generation RL if there will be one will be better but right now the TL is the better package. Nothing on the RL would make me say I wish I had that (maybe the power telescopic wheel) The RL is a fine package though hand sanded paint process etc, but through to the lack of advertising it suffers.

037

RL got cooled seats, noise cancellation system, 10 speaker Bose, cabin real wood for CMBS...I'm sure I'm missing a few.

Oh yea, it's made in Japan.

rockstar143

iTrader: (6)

Hand sanded, and all the mentioned things above are def. good reasons to consider the extra scratch.

db22

perfect!