One reason DRLs shouldn't be opposed...

It not only is possible, it is the norm for small cars with small
engines. The difference in mileage is often quite substantial (10% or
so). Larger vehicles tend to do as well or better with an automatic,
however, really large vehicles (OTR rigs) still do better with manual.
There have been attempts over the years to develop an automatic for the
large trucks, but so far they've not succeeded ... at least not the last
I knew.


Matt

 

Sure it is. It is using some of the gasoline that was used to
accelerate the car to speed or to climb the hill that it is now going
down. There is no free lunch.


Matt

 

What is a small engine? A 1.5 with an automatic I'll agree with you.
Most 1.8 L or larger engines with 4 speed (or more) automatics with
locking converters will give the average driver of a manual trans one
real good run for his money.

 

Matt, it uses the same amount of fuel to accelerate whether the lights
are on or not (in addition to what is required to run the lights) andf
on decel, even with the lights on, the fuel injectors on many cars are
shut off COMPLETELY. The alternator is still charging, and using no
fuel. The kinetic energy of the car in motion runs the alternator -
and the alternator slows the car down marginally.

 

| On Wed, 04 Aug 2004 17:47:26 -0400, Matt Whiting
|
| > wrote:
| >
| >>
| >>
| >>>
| >>>Larry Bud wrote:
| >>>
| >>>
| >>>>Hey Dan, bite me. Are you an asshole in real life, or just on usenet?
| >>>>
| >>>>There is hardly a discussion of any calculations here, except for the
| >>>>info on howstuffworks, and they don't break it down per vehicle. 400
| >>>>million gals/year is peanuts. Nowhere in their "calculations" do they
| >>>>indicate the number of cars, or covert that into MPG. So I'll do that
| >>>>for you Dan.
| >>>
| >>>
| >>>I think the issue is that you were not aware of the principle of
| >>>the conservation of energy, which is taught in any elementary physics
| >>>course (high school level).
| >>>
| >>>Some people have little patience when confronted with ignorance combined
| >>>with arrogance.
| >>
| >>
| >> Another thing not taken into account is that whenever a car is
| >> decellerating or coasting, going down hill, etc, the alternator is not
| >> using ANY gasoline to produce the power. In typical urban driving
| >> cycles, that would be well up in the 25% plus range. If not in
| >> gridlock, possibly over 50%. Try driving an electric vehicle sometime
| >> to see. This will skew the calculations a bit!!!
| >
| >Sure it is. It is using some of the gasoline that was used to
| >accelerate the car to speed or to climb the hill that it is now going
| >down. There is no free lunch.
| >
| >
| >Matt
| Matt, it uses the same amount of fuel to accelerate whether the lights
| are on or not (in addition to what is required to run the lights) andf
| on decel, even with the lights on, the fuel injectors on many cars are
| shut off COMPLETELY. The alternator is still charging, and using no
| fuel. The kinetic energy of the car in motion runs the alternator -
| and the alternator slows the car down marginally.

It's still the same amount of kinetic energy that has to be made up to maintain
vehicle speed. Think about it. Downhill at 60MPH with DRLs the car increases
speed by 5MPH...without it increases by 6MPH...the car will coast farther on
the flat or at the next hill before fuel is required to maintain
original/desired speed if the DRLs are off. Where the energy would be close to
being "free" is when coming to a stop where the kinetic energy would normally
be wasted in the heat of friction within the brakes anyway.

 

From
http://www.findarticles.com/p/articles/mi_m3059/is_2002_June_1/ai_88679770
:

"Another trend is the use of automatic transmissions in
heavy-duty trucks. Last year, 18% of all Class 8 trucks
built and sold were equipped with automatic transmissions,
up from 5% in 1996. "A big factor is the change in the
responsiveness of diesel engines as a result of pollution
controls," he explains. "Despite all the electronics on
today's engines, there can be up to three seconds of low or
no torque between shifts when you use manual or automated
mechanical transmissions."


Also see
http://www.roadstaronline.com/2004/05/056a0405.asp
http://www.istate.com/idd/products.php?kind=allison
http://www.allisontransmissions.com/documents/product/specs_HS.pdf
and/or
http://www.allisontransmissions.com...issions/model/hs/index.jsp?CTAMR=distribution
http://oee.nrcan.gc.ca/publications/infosource/pdfs/E_Transmissions_Book.pdf


Allison has been making automatic transmissions for large
trucks for at least 30 years. The difference in mileage is
minimal (and possibly the automatics actually can do better
now). The difference in maintenance is not - the trucks with
the automatics almost always cost less to maintain. However,
they aren't cheap to buy, and most "professional" drivers
don't want them.

Regards,

Ed White

 

They won't get me as a customer.

 

20 years ago.... not so today.

 

They don't necessarily "do better," and more and more fleet buyers of
big trucks are going with automatics (FWIW- Greyhound busses have been
mostly automatics since the early 70s). Owner/operators will always go
for gear-jammin' instead of automatics as a matter of pride and
preference, but the fleets are seeing the benefits of autos more and more.

 

Yep- the voltage is proportional to how much current the alternator
pushes into the load/battery combination. Ohms law still applies- the
alternator produces a current, which results in a voltage... and its
that voltage that the regulator senses.

 

Me either. Its Chrysler first (until Diamler screws it up too bad) and
then Ford. Warts (aka modular engines) and all, I still prefer Ford
over GM by a wide margin.

 

WHy does someone ALWAYS have to ruin a good wisecrack by actually
taking it seriously... :-/

(Corvettes may be fast, but they're still Chevys)

 

BZZZZT! Wrong again.

The alternator load slightly decreases the distance that the car will
coast at the bottom of the hill, meaning that you have to get back "on"
the gas sooner than you would have if the alternator hadn't been drawing
any power.

You NEVER get something for nothing, not as long as the laws of
Thermodynamics are in play.

 

BZZZZT! There you go, trying to violate the laws of physics again.

 

Me and my family's experience with GM products have all been bad. So even
without the DRL and data recorder fiascos I would not consider them. We've
had good results with Chrysler, Ford, Nissan, Toyota, and Mazda's.

 

Yes, and this marginal slow down means that more gas is used to climb
the next hill. As much as you want to believe it, it takes chemical
energy to create electrical energy in a car.


Matt

 

I don't consider 18% market share to be a success. Maybe in another 20
years...


Matt