Another very small incremental improvement in efficiency, 6% is quoted. So if we have a car that uses 20%, which is quite high as efficiency goes, of the potential energy in a gallon of gasoline and gets 30 mpg, a 6% increase would be .20 x .06 = .012 gain in efficiency, a one percent gain.
Or, 30 x .012 = .36, Or, about a third more mile per gallon.

Wonder what this wondrous mechanical engineering experiment cost and is it really worth bringing to market. Perhaps the money would be better spent on adding an electric motor/battery.

In other news, ZF believes their new buggy whip is more efficient, takes less effort from the driver and will get an extra 3% of effort from a team of two horses!

Lad:
Agree with the 6% (relative to previous) corresponds to 1% (absolute). But you are applying the wrong percentage to the MPG, so it is 1.8 more MPG.

Any efficiency boost now, is better than no boost at all. 1% improvement over 10s of thousands(even millions) of vehicles does add up. The sooner its implemented the more vehicle miles it effects....

Okay, I can totally appreciate an electric drive system, and I would love a battery car with the capabilities and range of my current car (could happen), but I don't know why people here are fussing over the addition of a planetary gear set into a technology that's been around for a long while.

The same thing can be said about complication and cost when it comes to EV's batteries. Most chemistries pose a fire risk, require thermal management, safety circuits, etcetera which all grow with the number of Kwh available to the vehicle. To electrify light duty trucks we may see 150Kwh+ battery packs.

If you look at the MTBF for a cell, and you take how many hours a vehicle is in service, then you multiply how many cells by the hours, then divide by the failure rate... you could see how scary a proposition it would be for certain long range EV's especially it is a larger vehicle. Yes, modularity and very good monitoring can reduce the downtime/effect, just something to think about,

I just don't see anything that jumps out and screams that this transmission is vastly more complicated or vastly more expensive than slush boxes of the past, sorry for the rant.

I probably overreacted, but I dream of a holistic approach in the near/mid term... one that includes PHEVs, and lots of them... even plug in FCVs.

Think of the longer gears, the engine off operation, getting to a destination without using fuel, AWD, regen-braking, overnight charging, hardly any engine maintenance on almost every vehicle... but none require an impressive yet to be released battery, nor are dependent on such a battery for its day to day operation. The volt is a great example. 60 miles electric capacity on a vehicle would easily reduce the operator's fuel consumption to zero most days of the year.

CheeseEater, you reminded me that
most, if not all transmissions (since 2000 at least) just get rebuilt at a remanufacturer, it cheaper to just swap for a rebuilt.

I agree that back in the day, repair of three-speeds used by those 350 cubic inch engines was indeed practicable. However, following the advent of five speed or more sophisticated transmissions with their electronic interface to the ECU it is no longer so. At least not unless significant proprietry technical resources are made available.

I would have to rebut that the more pricier rebuild may be the option for late model vehicles, but often or not, particularly outside of the warranty, it is increasingly becoming a deal breaker with older vehicles.

ZF provides complex mechanical solutions in a world that is intent on moving the complexity part into the electronics where the reliability improvement is a thousand fold. In this world only the simplest mechanics will exist.

On this note I predict that even Tesla will eventually eschew the differential final gear that is possibly giving them the occasional gear lash problem (from what I read) in favour of a slightly more robust twin motor drive.

In manufacturing you strive for repeatability and reproduceability. That these goals are more easily reached with electronic systems is probably an understatement.

CE88 makes some very good points.

An 8 speed is repairable while most electronic things like radios, televisions etc. are disposed of when they fail.

When a ICE or EV car has electrical problems you usually must take it to a professional or, if it is older, live with the degradation - but you can fix the brakes, suspension, belts, radiator and low fluids yourself.

Electric/hybrid (as well as ICE) vehicles are getting MORE complex (while those that think this is due to a conspiracy are staying simple).

At 3.5% of the market EVs save little gas; they are indeed "a market that is a thousand times smaller."

And the decision of where the money is best invested should be made by those that have earned it.

Thanks for the responses. You are obviously more adept mechanically than I. Perhaps I ought to have stopped by my local transmission shop for their take before I posted.

My life experience through aquaintances, who have kept older vehicles on the road, is that despite having immaculate interiors, no dings nor any signs of exterior rust at 150k kms will never be enough to prevent these vehicles from going to the crusher when their transmissions begin to fail. They just shrug and start searching for the next and newer CPO.

CE88 , you countered mechanical reliabilty by introducing the question of EV battery longevity. I have to agree that this is a sensitive matter over on the Tesla Motors forum.

There are a number of members on that website who are also owners of the Model S . Several of the latter group seem to be unaware that they are still in the early adopter phase for vehicles of that type, specifically the 300+Hp electric sedan. Regardless of that they persist in clocking up much more mileage than the average 1000 miles/month usually demanded from a typical gas car. One particular character increased his odometer reading by 17K miles in just four months !

Now we know that for the S85 (denotes the 85Kwh battery version) the complete powertrain warranty is eight years with unlimited mileage.

The problem is trying to get a fix on exactly what this warranty supports in terms of battery failure. Leaving aside the obvious pack total failure, how the battery pack warranty intends to deal with a pack whose charge retention is beginning to deteriorate needs to be answered. On this Tesla is somewhat vague.

There are of course a whole bunch who are quick to dive in and attest to their packs proficiency after 40K miles etc etc. Then there have been extreme cases that allow Tesla to extend some goodwill and do a full replacement. But there are now increasingly more cases where the company factors in the usage delivered and replaces the pack with one of similar wear. In some of these cases customers have turned around and demanded a pack which is capable of the original mileage at delivery on the grounds that so_and_so has reported that his battery is only a couple of miles down after a full year of use.

That of course is the problem. Perhaps so_and_so has a commute where he doesn't exceed 45mph whereas the other profligate owner likes to bury the needle so to speak. Of course the console display is merely a computer prediction based on best practice modelling and headwinds and low ambient temperatures will also eat into the rated miles as displayed on that console. For the future maybe they should consider the pack's Kwh storage - let the supercharger decide - at ownership change and leave the car and the rest of the powertrain out of the equation.

Finally mechanical transmisions are based on a mature technology with lots of history whereas battery packs are only on their second iteration. Time will tell.