TL Dawg

Hey guys,


I was just wondering if anyone could explain to me what the differences are (functionally) between what Acura offers versus BMW, Mercedes and Audi. Or better yet, what the higher performance cars put out.

I actually had the oppurtunity to test-drive the new TL and I wasn't overly impressed with "paddle-shifting". Maybe it was me and I was doing it wrong. It just didn't seem as exciting as driving a true manual tranny.

The Dawg

dramsey

The first thing you need to understand is that there are two basic transmission types:

Manual transmissions use separate gear sets on two shafts; meshing a pair of these gears determines the "gear" you're in. A clutch connects the gearbox to the engine.

Automatic transmissions are completely different internally. They use planetary gear sets connected to the engine with a fluid coupling/torque converter rather than a clutch.

Either transmission can be controlled via a variety of methods. Traditionally, manual transmissions use a gear shift lever and clutch pedal, while automatics use a gear selector lever.

Automatic transmissions shift slower and are less efficient than manual transmissions (energy is lost in the fluid coupling) but are easier to drive for most people and more reliable long term (no clutch to abuse and wear out).

Recently, more cars are adopting a computer-controlled manual transmission (where the computer shifts the gears and works the clutch) instead of an automatic. The benefits are faster shifts than any human could manage without the efficiency losses of a traditional automatic. These transmissions typically offer both a "D" automatic mode as well as manual control via paddle shifters. These are called "sequential manual" transmissions (SMG). A variation on the design is the "dual clutch" transmission, which consists of two gearboxes (one holding the even gears, and one holding the odd) each with its own clutch. These transmissions offer the best performance and efficiency but are significantly more complex and expensive that other types of transmissions. This type of transmission is typically used in higher-end sporty cars, although many Volkswagen models offer it now.

Paddle shifters can also be used with ordinary torque converter automatics. In most cases they merely offer an alternative shift method to the traditional lever-style selector; and most cannot match the shift speed and performance of a sequential manual transmission.

Acura has no sequential manual transmissions; all their paddle shifters back otherwise standard automatics. It's a nice convenience feature, allowing you to quickly select a gear without removing your hands from the wheel. But the shift quality and speed will not approach that of a true SMG.

bmode

The only thing I don't like about the paddle shifters is that it takes two hands to use them. In Cali, most of us drive with one hand as we ghost ride the whip, JK. But seriously I still keep going to the gear shifter for that "tip-tronic" shift in my old TL. I kinda miss that. I mostly used it to down shift when coming to a stop. The one bright spot in the 09' TL is that you can stay in "D" gear and still activate the paddle gears without touching the center console shifter, and it reverts back to auto drive. A nice feature there as you don't have to worry about shifting back up.

PetesTL

I wish Acura offered a true "Sport" mode with their 5sp.AT, similar to what BMW's have. When I had my '05 545i, there was quite a difference in the car's reaction times and dynamics when the trans was put into "S" mode over the normal "D" mode. To me, the paddle shifters are more of a neat gadget than anything really useful....I find my TL to actually shift faster and smoother in the normal "D" mode than with using paddle shifters. The problem with "grade logic" transmissions and drive-by-wire throttle systems is that the system needs some time to "learn" to your driving style before it fully adapts.

Wavehogger

Well Pete, as you know i've been 'playin' and learning more and more with my TL. What I can say for this wonderful 5 speed.. ahem.. is that in S mode it does shift differently. It will downshift more aggressively, taking you down gear by gear rev-matching nicely up to 5500 RPM and maybe higher I'm not sure yet, still playing. Which is very nice because in all of Acura's previous 5 speeds you couldn't get it to downshift until the next lower gear was around 3-4K and that wasn't very good because then you were way out of the powerband and VTEC. So I guess the positive side of us being stuck with 5 gears is that they did give us more versatility with this tranny. But if you leave it in D and try to get it to downshift quicky it pretty much acts like the previous trannys. Cheers!

bmode

I'll second that Wavehogger. Keeping it in "D" and down shifting with the paddle shifters is very smooth, and not what it used to be in my 05' TL. It's almost like a automatic mode, it won't rev high? However, I'm am using it Pete, so I wouldn't say it's useless, but true it is kinda of a gadget, a gadget that I will use. The car is getting better and better every day ain't it? I get so many looks in LA freeway traffic it's sick. I just need to switch out the rims, coming soon.

PGSberg

The best use I can find is that driving at higher speeds during rush hour, taking your foot off the throttle doesn't slow the cars down now adays. The paddles are great to bump down a gear or two rather than riding the brake and bump back up.
During hard acceleration the car shfits smoother and quicker in "D". I do notice that when using the paddles, the response is instant - not a big pause as I found in the IS250AWD I had. I rarely used the paddles in the Lexus.

PetesTL

One thing I've noticed lately is that once I'd hit the 500 mile mark, the car is beginning to feel more "loose" and lively now than before when new. When I hit the gas hard now, the car launches with authority with absolutely no hesitation and doesn't seem to let up. I love the growl in the SH-AWD car over the base car......it sounds meaner and sweeter than on many of the cars I've had before.

BEAR-AvHistory

A manual transmission gears are all alway in mesh. What determines the gear you are in is which gear is locked to its shaft.

The part known as a dog collar has teeth called dogs on its inner surface which engages into slots on the gear & the gear shaft locking them together.

These dog collars are what actually move inside the transmission when you move the shift lever.

When you do pull the lever the dog collar applies force to a cone-shaped brass clutch attached to the gear, which brings the speeds to match prior to the collar locking into place.

The collar is prevented from bridging the locking rings when the speeds are mismatched by synchronizer rings, also called blocker rings or balk rings