Poor Hybrid sales threaten 2025 CAFE targets

Status
Not open for further replies.
Joined
Nov 9, 2008
Messages
23,725
Location
NH
http://wardsauto.com/politics/poor-hybri...tm_medium=email

Nothing surprising here; cheap gas, and better mpg in general.

Thought this was interesting, a bit about CVT/many speed transmissions:
Quote:
Conventional step transmissions will remain in the mix for the foreseeable future but will evolve at a much faster pace, says Dean Guard, director-Global Engine Engineering, GM Powertrain. The number of gears will continue to grow and CVTs are gaining favor, especially at General Motors, Guard says.
Rather than looking strictly at the mechanical efficiencies of transmissions, GM now is taking a more holistic, physics-based approach to how it evaluates the interplay between engines, transmissions and the entire vehicle.
“We know step-gear transmissions are mechanically more efficient than CVTs, but maybe what we didn’t fully realize is the CVT transmissions could match well with the engines and give us better combined fuel economy due to effectively infinite ratio capability,” Guard says.


More than 10 speeds? That will be interesting. I thought 10 would be deep inside the point of diminishing returns.
 
Originally Posted By: Miller88
Isn't it published somewhere that anything past 6 is diminishing returns?

I would've thought so too, but it seems with pickups atleast, jumping from 5 or 6 speeds to 8+ does help mileage a lot.
 
To me, this just shows how easily lead the majority are. Give us lower gas prices for a while and somehow think that a gas guzzler is ok....its extremely short sighted.

We're hooked on oil, we've all been born into this system so its not surprising but to be shallow and not look at the deeper truths of the whole oil/energy/economic/population picture is stupid.

Im starting my car less and riding my bike more. I just turned off my hot water heater for the next 6 months.
 
Originally Posted By: stro_cruiser
Im starting my car less and riding my bike more. I just turned off my hot water heater for the next 6 months.

So you ride a bike and don't take showers?
 
lolol I ride my bike MORE than I did and take COLD (you cant really call it cold) showers, this is south Florida!
smile.gif
 
Originally Posted By: Miller88
Isn't it published somewhere that anything past 6 is diminishing returns?


I would think so as well, but wouldn't it really depend upon the final gear ratio and number of OD speeds?
 
Last I looked the ZF nine speed took the eight and added a crazy tall 0.48 overdrive. Which probably only engages going downhill at 80mph. Or for coasting, so as to reduce drag.

Which would bug me. I like engine braking, and prefer it to riding the brakes.
 
Originally Posted By: stro_cruiser
Im starting my car less and riding my bike more. I just turned off my hot water heater for the next 6 months.

Bike riding is an option 6 months of the year here, while the tap water is slightly above freezing most of the year.

Your showers would be mighty short given our tap water temperature.
smile.gif
 
Originally Posted By: stro_cruiser
I just turned off my hot water heater for the next 6 months.


Isn't it the ultimate in waste to heat hot water?

We simply use a highly efficient "water heater" and leave it turned on year round.
 
Originally Posted By: WobblyElvis
When I drive a car with a six speed, it feels like it's shifting too much already.


Six feels like the majic number to me.

Four is not nearly enough. Eight is way too many.

I don't enjoy driving CVTs.
 
With modern peak-y engines, how long before we end up dropping the thing out of it's efficient range? If my 2.0L NA I4 was idling along at 80MPH, it's going to get much worse mileage than 2500RPM ...
 
Typical consumer behavior, when gas prices go up again they will buy fuel efficient cars.

On the truck forums everyone is about the 3/4 ton now, no one wants a half ton. I remember when fuel prices spiked in 2008 you could buy a brand new 3/4 ton for a song.
 
Last edited:
Originally Posted By: Miller88
With modern peak-y engines, how long before we end up dropping the thing out of it's efficient range? If my 2.0L NA I4 was idling along at 80MPH, it's going to get much worse mileage than 2500RPM ...

Our motors are some of the last that are "peaky", as they don't have variable valve timing, or a turbo, or variable intake runners, etc... Ford did a good job in tuning them for normal rpms so they feel quite torquey, but with no tricks they run out of torque at higher rpms compared to a new 4 cyl. Also if the motor is tuned for it, you would the most efficient power output at WO throttle at quite a low rpm. 1600-1800rpm? With all the overdrives in a new trans and drive by wire, I think you would be surprised how open the throttle plate is in the highest gears when the driver is just nudging the pedal to maintain speeds.
 
I am surprised at how low my 2.4L 2013 Sonata can go in the rev range before calling for a downshift.

Top gear lock up, 1,300 rpm at 45 mph is pretty common cruise mode.
 
Originally Posted By: hattaresguy
Typical consumer behavior, when gas prices go up again they will buy fuel efficient cars.

On the truck forums everyone is about the 3/4 ton now, no one wants a half ton. I remember when fuel prices spiked in 2008 you could buy a brand new 3/4 ton for a song.


I remember back when things slowed down in 2008 and gas prices went through the roof I came across a 2 or 3 year old Suburban with the Vortec 8100 for something stupid like $5000. I realllllllly wanted to buy it ... but had no use for it.
 
Originally Posted By: Miller88
With modern peak-y engines, how long before we end up dropping the thing out of it's efficient range? If my 2.0L NA I4 was idling along at 80MPH, it's going to get much worse mileage than 2500RPM ...


Not the case at all. Wide open throttle (WOT) operation reduces pumping losses and reduces BSFC increasing fuel economy. Ultimately we'll get nearly-continuous WOT operation and vary engine speed to match the load.

Today's engines are much more flexible than in years past. Who's still driving a 4AGE equipped Toyota? The early 4AGE was not big on low speed torque, but had great RPM potential. These days even my lowly 4 cylinder Frontier pickup has VVT. It idles at 600 RPM and pulls well from just off idle to over 5500 RPM. Almost nothing from the 1980s would do that.
 
Fuel consumption is not linear to RPM. Especially with GTDI engines that have to overfuel to prevent pinging.

If I were to gear my Focus so that I had to hold my foot to the floor to maintain 65MPH, while at 750RPM ... it's going to get significantly worse fuel economy.

Yes, there are less pumping loses, but there is much more to it than just pumping loses.
 
Status
Not open for further replies.
Back
Top