from leftlanenews

 

Point? The thing would constantly be shifting between gears, what does it have like 3 overdrive gears? Now they are just getting silly.

 

How many speeds does it have to have before it becomes indistinguishable from a CVT?

I've found that four speeds is about all that a competent driver can handle effortlessly with a conventional shifter. Adding a fifth really complicates things, unless it is simply a tall overdrive gear that is seldom used in normal driving.

The only way to go with more gears is sequential shifting, something the motorcycle people have known for decades, but which for some reason is the latest kewl thing with automobiles. The only reason to have more speeds is to keep the engine in the optimum RPM range at all times as that range gets narrower due to tuning. I don't think that many folks will really want to drive a car that makes decent power only between 8000 and 9000RPM! I've had motorcycles like that and they were pains to ride.

The fact is, we are seeing the last round of manual transmissions. Automatics have become so good that they are surpassing manuals in mileage. The only fault they have is a lag in downshifting because they cannot react until the driver hits the gas. When this problem is licked, the manual shift lever will become as obsolete as the spark advance lever and choke buttons.

George <--whose xB is probably the last stick shift he will own.

 

now THIS is an automatic transmission!!

 

Mack Trucks (18 wheelers) have anywhere from 5 to 18 gears....

 

Mack trucks have that many gears because they NEED those gears...u realize how short those gears are? and they are ALL for pulling...u listen to a fully loaded big rig shift they are MAYBE in each gear for like 2 seconds...and they probably shift gears 5+ times before they are even totally out of the intersection! but if u hear the same rig NOT loaded...there is a good chance they are starting off in like 6th gear!

To me, I dont see the need for 8 gears in a car...I mean, I guess it's kinda cool...but 5 speeds are just fine with me...as for my box, I really want a 6th for freeway cruising!! Mercedes puts their 7-speed in a car with 400+ HP...so it makes at least a little bit of sense...its going to use ALL of those gears to give you a smooth power delivery, and make it a more civilized ride (civilized = old people). ME, I prefer hard shifting and neck breaking acceleration!

To each his own...

 

IMO - I think more gears in an automatic transmission makes for smoother shifting to where you don't feel the car shifting. Some will say CVT does the same thing, but CVT is for front wheel drive...not RWD. so...when it comes to the luxo brand cars...I.E. BMW/MB/Lexus etc.... you want silky smooth shifting. and also you don't want a loss in RPM's when the car shifts, just 1 continous motion forward with the RPM needle.


I guess thats what more gears are for

 

A high number of gears would allow for an engine that is high-torque, but low horsepower, to still be driveable.

 

all those gears are unneeded unless you have very narrow powerband like a semi. after that its just a waste for anything other than bragging you have more gears.

 

and the semi trucks have a 2 speed diff one high one low!!!

 

The Honda Jazz uses a CVT that has a "7 gear mode" for manual shifting. More than likely Toy is planning something similar.

 

The reason for all the gears is better gas mileage. It is even more effective when you have a big engine with lots of HP. That is why the rush is on for larger speed trannys especially with all these SUV and V8 auto's. Manufacturers need to get better gas mileage.
A larger speed transmission is more expensive to manufacture.
Remember CVT transmissions get the best mileage because they have an infinate number of gears. The trick in all of this is to get the tranny to shift smoothly, then it does not matter how mny gears you have!

 

More gears is only true to a point for better mileage but you can only go with so much OD before the car runs out of power. Then you just add more gears in the middle and they get so close together that must are not needed. If anything more gears do better on smaller engines which have to work harder to move a heavy car or ones with narrow powerbands.

 

when you have more gears like that there not added all on the end they are all changed they will have shorter starting gears wich means the car will be stronger off the start and then you have the normal gearing range and then youll have a longer od range wich results in better gas mileage i know that every one of you that have a manual tranny tc have wanted a 6th gear on the highway the tc has low enough starting gears but crusing on th highway at 4 grand really hurts the gas tank with another gear you could get considerably better gas mileage i would not be surprised if they add a 6th gear to the tc

 

i hope m/t dont go away, I would like to learn how to drive one! then I can get a manual, i already drive with my hand on the shifter, anyway....

 

Its amazing how many transmission experts there are.

 

...ZF can build a great transmission , but only one-at-a time .
...example : the tranny plant in Batavia , Ohio .
...their CVT for the masses failed .
...hmmmm , product or management?

 

Since i'm drivin a 5 Spd tC having a 6th gear ain't such a bad idea (for highway cruisin @ 70 MPH around 2-3K RPM), plus changing 4th & 5th to be even shorter...
I'm not claiming to be a tranny expert, but 8 gears seems like its too much (atleast for an under 350HP car).
Manuals will ALWAYS be classic. And I don't see it going away any time soon (even though it might not be made anymore in the future it'll still be around somehow & someway).
I do however see a ton of potential in the CVT design. Perhaps its primarily used in hybrids to save gas, but the concept itself is breakthrough.
In the same way Honda developed Vtec, I see CVT being optimized for high performance applications.

 

I know its a new application n all...but I would hardly call it a breakthrough...its got the same basic principal of a centrifugal clutch on a minibike or go-karts...Manuals will always be around because of their (relative) simplicity and durability...

 

I was putting it in the context of "Continuously Variable Transmission" meaning "in theory" continuously optimizing for maximum performance & efficiency.