why so many multi speed automatics?

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Emissions must factor too, somehow. I'm quite sure I could lug my engine to better mpg but it would rather downshift. Closer spaced ratios means the engine doesn't have to spin faster than necessary.
 
You could not possibly know if you need a 9 speed tranny until a marketing campaign would finally let you know. Between government regulations and product marketing you will come to know exactly what you need in a next new car. Just make sure you don't entertain any nonsense about keeping a car past the factory warranty. Feature creep is far more important than longevity, just as any car salesperson. Don't be embarrassed by being seen in last year's new car. That old car of yours might only have a 6 speed transmission and what possible explanation could you give for driving a dinosaur like that?
 
Originally Posted By: edwardh1
why just recently do you see more 5, 6, 7 ? speed automatics? Has there been some break thru in auto trans design in the last 5 years that did not exist in decades past?


Ed, it's about ratio spread. Smaller engines, heavier cars, and higher mpg requirements are why we need ratio spread.

This is exactly why engineers love wide ratio spread cvts. More gears keeps the engine in the power band when you need acceleration and yet allows ultra low rpm cruising for high mpg.

Frankly the ZF 8 speed is in so many different cars from Bentleys to BMW's that I don't know why EVERY car maker isn't using it...
 
It is kind of like those razor ads you see on TV telling you how great the latest razor is because it has 6-8 blades or whatever. You "need" this! Once you get onto the highway you can only have so much of an overdrive ratio or the engine will lug and not push the car anymore. Most of the new cars still have a similar final drive ratio they have had for years but the extra gears keep the RPM's down in city driving.
 
Originally Posted By: SteveSRT8
Originally Posted By: edwardh1
why just recently do you see more 5, 6, 7 ? speed automatics? Has there been some break thru in auto trans design in the last 5 years that did not exist in decades past?


Ed, it's about ratio spread. Smaller engines, heavier cars, and higher mpg requirements are why we need ratio spread.

This is exactly why engineers love wide ratio spread cvts. More gears keeps the engine in the power band when you need acceleration and yet allows ultra low rpm cruising for high mpg.

Frankly the ZF 8 speed is in so many different cars from Bentleys to BMW's that I don't know why EVERY car maker isn't using it...


It' still probably more expensive than developing something in-house. Ford/GM has been working together to save development costs - but not sure how reliable those will be. Toyota makes their own ... obviously going to be reliable there.
 
"The main transmission shaft is another technical highlight of the 9G-TRONIC. First, at 550.9 millimeters, it is one of the longest shafts in the entire automotive industry. Second, it performs other functions in addition to its main purpose of power transmission: using a sophisticated internal ducting system, the shaft also performs various lubricating, cooling and control functions."

It's easy to guess what happens with this kind of systems with "lifetime" fluid. Channels get blocked with dirt coming from the clutches, and eventually everything falls apart.
 
Its like Gillette constantly adding blades for a "closer shave"
The best razor I ever owned was the 2 blade Gillette Sensor, what are they up to now nine blades?!

Or adding megapixels to cameras...

At somepoint it is the law of diminishing returns.

My sisters 1993 accord with a 4 speed- returned AMAZING gas mileage... (And it was bulletproof)

Just sayin'
 
Maybe it's a sign that multi-speed transmissions will be a better solution then a CVT. The most reliable one of them all would be the Prius when is not a CVT an has only one gear forward and no reverse and never shifts from one gear to the next.
 
My sister's ford freestyle has a ZF AWD CVT, and has been very reliable. Of course while dad owned the car, he followed the maintenance schedule to the letter, including the $5-600 transmission service,every 30,000 mi.( I'm still not convinced that service was more than a fluid change...)
 
Good news for manual's..except the part about performance. I wanna see if a manual Hellcat can hit that 1/4 mile number.


"The 2015 Dodge Challenger SRT Hellcat is offered with the buyer’s choice of a 6-speed manual transmission that was borrowed from the Dodge Viper and a newly designed 8-speed TorqueFlite automatic. While most people expected that the self-shifting transmission would be the more popular of the two gearboxes – early sales have told a different story as the manual transmission has outsold the automatic by a ratio of about 55/45.

The New TorqueFlite Arrives

Since the information on the 2015 Dodge Challenger SRT Hellcat began trickling out, the majority of marketing attention has included the new 8-speed automatic and there are plenty of good reasons for that. First and foremost, the TorqueFlite automatic was the transmission used for the NHRA certified quarter mile times of 11.2 with stock tires and 10.8 with drag radials. Those are smoking fast times and they can be achieved with less experience than a comparable Challenger with the 6-speed manual so for those looking to go fast, the TorqueFlite is the way to go."
 
Originally Posted By: OneEyeJack
Maybe it's a sign that multi-speed transmissions will be a better solution then a CVT. The most reliable one of them all would be the Prius when is not a CVT an has only one gear forward and no reverse and never shifts from one gear to the next.


Not a CVT? What is it then? Here is a hydraulic clone of it with 2 range gears:

https://www.youtube.com/watch?v=dgtIKMAjvFI
 
Last edited:
Originally Posted By: LFN
Good news for manual's..except the part about performance. I wanna see if a manual Hellcat can hit that 1/4 mile number.


"The 2015 Dodge Challenger SRT Hellcat is offered with the buyer’s choice of a 6-speed manual transmission that was borrowed from the Dodge Viper and a newly designed 8-speed TorqueFlite automatic. While most people expected that the self-shifting transmission would be the more popular of the two gearboxes – early sales have told a different story as the manual transmission has outsold the automatic by a ratio of about 55/45.

The New TorqueFlite Arrives

Since the information on the 2015 Dodge Challenger SRT Hellcat began trickling out, the majority of marketing attention has included the new 8-speed automatic and there are plenty of good reasons for that. First and foremost, the TorqueFlite automatic was the transmission used for the NHRA certified quarter mile times of 11.2 with stock tires and 10.8 with drag radials. Those are smoking fast times and they can be achieved with less experience than a comparable Challenger with the 6-speed manual so for those looking to go fast, the TorqueFlite is the way to go."






Who cares if it shifts faster?!

For me, it is just much more enjoyable to have a TRUE manual transmission.
But to each, their own.
 
Originally Posted By: Nickdfresh
Originally Posted By: Olas
It's because people are too [censored] lazy to change gear.


LOL
laugh.gif


I wish my manual had a 6th overdrive...


What car? I can't believe your fifth isn't over drive, never mind 6th! Just about everything is drive in 4th, under in lower gears and over in 5th an upward..
 
Fifth probably is overdrive. Sixth would be a second overdrive. My two Toyotas are that way, fourth is direct.

But really it doesn't matter, not as much as bringing rpm down. the I4 RAV4 4spd auto for a few years was actually an under drive in top gear. But with a tall final drive it didn't matter as much as you would think.
 
Originally Posted By: Olas
Originally Posted By: Nickdfresh
Originally Posted By: Olas
It's because people are too [censored] lazy to change gear.


LOL
laugh.gif


I wish my manual had a 6th overdrive...


What car? I can't believe your fifth isn't over drive, never mind 6th! Just about everything is drive in 4th, under in lower gears and over in 5th an upward..

What constitutes overdrive? Presumably a gear ratio of less than 1? My 530i is right at 1 in 5th gear.
 
Originally Posted By: CHARLIEBRONSON21
Surprised they even make so many gears and don't just jump on the cvt bandwagon.

Historically, CVT has had trouble with reliably handling large amounts of torque/power.
 
All the reasons for using an 8-speed transmission have been mentioned.

However, I have heard some people say they would be impossibly expensive to rebuild. I disagree.
FWD was supposed to be impossibly expensive to rebuild. Somehow, transmission mechanics and parts companies made it affordable.
Overdrive transmissions were supposed to be impossibly expensive.
Electronic transmissions were supposed to be impossibly expensive to rebuild. Eventually those went down in price to rebuild as well.

8-speed transmissions and DCT transmissions are expensive to rebuild now. However, how many parts companies and mechanics understand them?

Also, just because an automatic transmission was purely mechanical and had 3 gears did not mean it would be cheap to rebuild. Just look at some of the older European cars, such as the SAAB 900.
 
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