Smart 451 Automatic Transmission Conspiracy

[hoov23]

Hear me out. We all know (450 owners) that our cars have 6-speed semi-automatic (aka automated, electrohydraulic) single-clutch manual transmissions. Anyone who's driven a BMW SMG car knows that it's the same transmission, the same shifter, the same feel. Ferrari F1 and Maserati Cambiocorsa are also the same, they just are deprived of the console shifter and are only given paddles and reverse and automatic buttons. But they all use a single clutch with no clutch pedal. We all know they aren't automatics. There are also many new double-clutch gearboxes out now, which are much smoother, like Audi's DSG and the new Porsche DPK.

Porsche had Tiptronic shiftable automatic transmissions for years, and nowaways every mundane automatic car is "shiftable." Torque converter.

The thing that gets me is the new North America 451 Smart. I swear it seems like they have a shiftable automatic trans but EVERY person that I've told in America denies it and says it's an automated manual. If you look at the shifter of a US 451 and a Euro 451, you'll see the Euro has the same type as a 450 but the US 451 has P R N D and moves to the side for "manual" shifting. It has a button on the front that you push to move the shifter. If you drive a US 451, you'll notice that from a stop on level ground, if the car is in D or R and you release the brake, it will move on it's own, not roll but drive. Manuals don't do this in my experience. ALSO the feel of driving the cars is very different from any automated manual I've ever driven, yet eerily similar to every automatic car.

I'm not just talking completely out of my @$$. I worked for years at an exotic car dealership, and I've driven almost every type of automated manual Ferrari, BMW M car, Maserati, and Lamborghini. In addition to that I've driven many shiftable automatic cars that have "paddle shifters," like Porsche, Aston Martin, and Bentley for examples. I used to have a Tiptronic 911 (PRND). We also sold about 75 G&K Smarts (including my own now with 31k miles) and over a half dozen 451's, which I've extensively driven on drives up to 2 hours and at max speed (which is lower than the 450).

And yet everyone says I don't know what I'm talking about. Can an automated manual be made to replicate the characteristics of an automatic? Can they be reconfigured to PRND and allow the car to creep without throttle? Or are the NA Smarts given different transmissions than ROTW 451s, with official documentation denying it? All it takes is for someone to confirm a torque converter in the NA parts catalog.

Anyone have anything to say about this - confirm or deny?

Look here for Smart USA's product description, under Engine/Drivetrain:
smart fortwo passion coupe

USA 451 Shifter:



European 451 Shifter:


450 Shifter (obviously):

[Old smart]

Here goes:

Originally Posted by hoov23

... I'm not just talking completely out of my @$$.

Yes you are.

And yet everyone says I don't know what I'm talking about.

You don't.

Can an automated manual be made to replicate the characteristics of an automatic?

Yes.

Can they be reconfigured to PRND and allow the car to creep without throttle?

Yes.

Or are the NA Smarts given different transmissions than ROTW 451s, ...

Slightly (the PRND and a parking pawl). The PRND is just a sop to the American driver teethed on torque converters.

All it takes is for someone to confirm a torque converter in the NA parts catalog.

Don't bother.

...

[forestacademy]

THe US Version has PRND only so It can be sold to folks in the US who have no idea what to do with a manual transmission. It sure drives like a Manual and has a Clutch just like a Manual, but it has no manual input to the clutch. Even is we wanted one their is no room in the footwell to add a clutch pedal.

If it was an automatic designed to be manualy shifted, it sure would shift a lot better than it does.

[jwight]

Confusing? Maybe. Conspiracy? Hardly.

[powerbookguy]

thread hijack. can the creep be turned off? it is really annoying.

[jwight]

Originally Posted by powerbookguy

thread hijack. can the creep be turned off? it is really annoying.

No, although full application of the brake cuts out the creep mode.

[WhiteNBlack08]

Check out your own link. When you look at technical specs, it plainly says:
"single plate dry clutch"

smart USA - passion coupe technical specs

[forestacademy]

Originally Posted by powerbookguy

thread hijack. can the creep be turned off? it is really annoying.

Be Glad you didn't have an 08 before the upgrade. That creep was harsh, and when you applied the break parialy it would squat.

Pop the car into N to turn it off if its a long light.

[hoov23]

I just read an article about the early American version which clarifies the differences between the US and Euro 451:

"The gear shifter in the [NA 451] smart fortwo reflects a standard American selector lever with Park, Reverse, Neutral and Drive (PRND) clearly marked."

"The automated manual transmission of the U.S. version of the smart fortwo is specially configured for use in the United States. First gear has a somewhat shorter ratio than the European versions to enable the smart fortwo to better demonstrate its spirited nature when pulling away at traffic lights. By contrast, fifth gear has a longer ratio for low revs and a low noise level when cruising.
Like an automatic transmission with a torque converter, the smart fortwo will also creep slowly when the driver removes his or her foot from the brake pedal in reverse or drive. This function facilitates parking or driving in stop-and-go traffic. In creep mode the car moves along at walking speed and can take uphill gradients of a five percent maximum. Creep mode is stopped as soon as the handbrake is engaged."

http://www.benzinsider.com/2007/10/t...-smart-fortwo/

I was unaware that "creep modes" existed in automated manual transmissions, and only having driven 08's with the "harsh" creep the difference between the 451 and the 450 was magnified. Thanks for the info all.

[John_H]

Accellerate hard from a stop. The delay from when the clutch applies in first to when power is finally back is waaaaay too long for a torque converter. I'm impressed with how well the "creep" works without bucking or surging, but it's still not a torque converter approach. Pull up the parking brake one notch when creeping and the power will immediately drop out and do so smoothly - not a braking issue - further suggesting there's no torque converter.

PRND is just a software difference. Control over the throttle is software, in the end, and can "allow the car to creep without throttle."

It's funky. It's decent but still sub-par. I understand a double-clutch (for a significant cost) is being investigated as well.