speedemn

I am curious as to how the new 5-spd auto w/ manual mode would compare to the 6-spd in terms of power to the wheels. Has anyone dynoed the two head-to-head or does anyone have separate dyno results even?

A lot of the newer cars (including the proposed new Skyline that is coming to North America) are being fitted with auto w/ manual mode, over the traditional clutched manual. I am wondering if these autos are getting to be as efficient or better than the manuals.

Generally (for FWD or RWD) a manual would experience about 15% drivetrain loss and an auto would experience about 25% drivetrain loss. But how do these new auto w/ manual mode (in manual mode) compare?

Any ideas?

Thanks.

dchengmd

Your numbers are about correct. Cars with automatic transmission with a "manual mode" are pretty much the same as automatic cars without the manual mode, except you have the option to shift the gears yourself. However, the inner workings of the auto transmission - namely, the torque converter - are still present, so the drivetrain power losses as well as the 'feel' of the car when you drive it are virtually the same.

This does not apply to the newer BMW cars with SMG (Sequential Manual Gearbox) or Ferraris with the paddle shifters - these cars are essentially clutchless manual transmission cars. Actually, the term 'clutchless' is incorrect as well - the clutch is controlled and actuated by a computer, which results in very fast gear shifts (80 milliseconds in the BMW) as well as computer controlled rev-matching.

If you're considering an automatic car with manual mode, just approach it with the attitude that it's about the same thing as a plain vanilla automatic transmission car. Also, keep in mind that if you plan on using the manual mode often, not all manufacturers approach it the same way. In the Z, the car will stay in the gear you pick unless you shift up/down, or slow down, so you'll hit the rev limiter all day if you don't shift. In the Lexus IS300, I've heard the manual mode STARTS in 2nd gear and will shift up for you if you come close to hitting redline. Kinda defeats the purpose of having a manual mode, IMO.

speedemn

Thanks for the clarification.

The reason I asked is because the new Skyline is rumored to have an 8-spd automatic transmission (with manual shift or paddle shift). If a true clutched manual is more efficient, I don't see why they wouldn't put that in a sports super car like the Skyline. They must have a good reason. Could the BMW technology have seeped into the Nissan workshop?

As for the manual shifted auto, I agree that it seems a little pointless to have it shift before hitting redline, like in the IS300... it defeats the purpose of having the manual shift auto.

I want a true manual tranny for my next car (I currently have a 5-spd manual Maxima) but if they are all starting to scrap the clutched manuals for auto/manual wannabe trannies then I hope they are doing it for a good reason (performance-wise).

dchengmd

8 speeds??? Holy cow!

By the time the new Skyline comes to the US, it may very well have a SMG-like transmission. Currently the market is slowly dividing into 3 camps - the auto w/ manual, true manual, and clutchless manual. It's been speculated in several car magazines recently that the true manual transmission will slowly be supplanted by the clutchless shifter over the next few years, given its better performance. Also, having an SMG-like shifter still allows the driver to drive the car in full automatic mode, so you essentially get the best of both worlds - although there have been some comments that BMW's current automatic mode in their SMG boxes still need a little work.

ThoughtZ

i've owned both a 5 speed auto with manual mode and 6 speed z. unfortunately the 5 speed was totaled so i decided on a 6 speed the second time around and the power to the whell difference is notable. i drove the hell out of that automatic so you can trust me when i say the power application especially at higher speeds is no contest to the freedom you have with the 6 speed. i mean you cant go wrong either way both are very good but if your determining factor is the most raw power at x rpm then go with the stick.

speedemn

Yes, reportedly 8-spd tranny. Here's the snippet of the article:

One of Japan's most reliable car magazines, Holiday Auto, is reporting
that Nissan CEO Carlos Ghosn will make a significant announcement
concerning the next generation GT-R at Nissan's Tokyo Show press briefing on Oct 22.
The car will not appear, but critical information will be revealed.

NEXT GT-R REVEALED
According to the report, Ghosn will outlay a launch schedule for the new GT-R supercar with an unveiling set for the September 2005 Frankfurt show. The car will then appear again at Tokyo and then at Detroit before Nissan reveals the final production version at Geneva in 2006. The report also confirms that the next GT-R will be powered by a specially developed 3.2 litre V6 with a new electrically-assisted twin turbo setup generating in excess of 480 hp (350kW) placing it directly in Porsche 911 turbo territory.

Sitting on an aluminium space frame, the GT-R will employ a steel cabin unit blending light-weight materials with high rigidity strength.
The hydraulic centre differential used in the the outgoing R-34 will be swapped for an all-new magnetic clutch configuration with a choice of 6-speed Getrag manual or an 8-speed CVT inherited and upgraded from the current V-35 Skyline GT-8.

A revised Atessa ETS 4WD system will also be incorporated while the GT-R will sit on 245/40R19 rubber. The new model will also employ 6-pot Brembos on the front and 2-pots on the rear. But while we can reveal these details today, the final styling of the GT-R has not yet been signed off, hence the absence of it from this year's Tokyo show. Nissan know they must keep price down, and several commentators including the Holiday Auto report suggest a price under 8 million yen.

Poison123

iTrader: (2)

Damn with stats like that on the GT-R I really don't want to think what its price is gonna be when it comes over.

Bat_Zignal

If they sell it here below 65K, it would be AWESOME!!!

speedemn

The article says 8 millon yen, which is about $100,000 I believe. That is comparable with other super-cars in its class I think.

Poison123

iTrader: (2)

100k *removes GT-R from list*

speedemn

$74,000 USD...

$98,000 CAD...

Is it back on your list? ;-)

Dissident

iTrader: (1)

By the time a car with a "Skyline" badge on it is actually sold in the US, all cars (except american ones) will have 8 speeds, and $100,000 will buy you two movies tickets, a medium popcorn, and a small drink....


(In the year twoooo-thousaaaaand....)


Seriously, "8-speed CVT" doesn't make sense, unless they are talking about a number of "presets" that make a CVT feel like a normal tranny. CVT is neither a manual nor an Automatic in the traditional sense: it has no gears/speeds, and so far, there aren't any out there that handle that kind of power that I know of. Not sure what HP losses they experience, and I bet it would vary greatly based on how the belt is designed, as there are a few different configurations out there, and some have much more slippage than others:

Donald0730

Here's my input on 5at vs 6mt.

5at- Artificial Sweetener

6mt- Pure Sugar!

dchengmd

Which makes no sense at all.

Boomer

This is a tired old song. Do a search and try not to repeat the same old b.s.

Boomer

This is a tired old song. Do a search and try not to repeat the same old b.s.

Poison123

iTrader: (2)

While the GT-R when it comes over here is supposed to have a MSRP of 75k, the demand will be so CRAZY (and you know it will) it will probably cost 100k after the dealer markups.

My wifes Mini Cooper has the CVT on it, and it truly the weirdest car i've ever driven when going 7-10mph. It feels like it yo-yo's back and forth, which is evidently something that happens in all CVT coopers.

As far as the CVT not shifting, I beg to differ, when that car is manualmatic mode it has 6 speeds on it. And even when in regular auto mode you can very easily feel it shift at 4k rpm's.

Dissident

iTrader: (1)

It is not really "shifting" and there are not 6 gears; jsut 6 set ratios that it will hold. What it does it hold a specific ratio, then at a certain point, it goes to another preset ratio, but there are no gears. There is a min and max gear ratio, and it adjusts in between there. It may be programmed to feel like it is shifting, to make it feel like a more normal car, or it may not just be adjusting very smoothly.

Does the Mini have variable timing? If so, that may also be what you're feeling @4K.

shinz

iTrader: (3)

As someone else had said, the CVT as of now, can't handle too much power, but maybe by the time the skyline comes out, it will have improved. I think currently, Nissan's cvt in the murano can handle up to 260 ft lbs of torque, and Audi's CVT in it's A4 can handle a claimed 224 ft lbs of torque, but i believe some people on Audiworld have gone past that limit. A chip alone for that car bumps torque from around 170 to a claimed 224, more or less, depending on the company. On another note, Audi claims it's CVT equipped cars are faster than it's manual cars, but im not sure how true that statement is.

speedemn

Which is possibly why Nissan would use that in the Skyline as opposed to the 6-spd. But I also heard that they would offer both... 8-spd CVT or 6-spd manual.

Time will tell.