stringent fuel economy standards looming in the U.S. and elsewhere, auto manufacturers
are looking to pull out all the stops to improve economy as much as possible.
Carmakers are turning to technology like direct injection and automatic start/stop.
Several automakers are also using cylinder deactivation on their larger
Cylinder deactivation is something that some carmakers in the U.S. and abroad
have used for years. Chrysler has used the technology in its Hemi engines,
Honda uses it on some of its V6 models, and Audi will use cylinder deactivation
in its new
line of “S” performance models.
VW is set
to make a first in the automotive market by offering cylinder deactivation on its 4-cylinder
The VW tech will turn off two engine cylinders under certain conditions. The
engine is called the 1.4L TSI and VW promises that it will offer a fuel
savings of 0.4-liters/100km and when combined with start/stop technology the
vehicle would save 0.6-liters of fuel. For those more familiar with U.S. mpg
ratings, that works out to an improvement of in the range of 3 to 4.5 mpg on average.
The engine would turn off two of the cylinders under low to medium loads, and
VW says that the tech will meet the future European EU6 emissions standards.
The cylinders will be deactivated when the engine is operating between 1,400
and 4,000 rpm and the engine torque is in the range of 25 to 75Nm.
VW claims that operating range applies to about 70 percent of the driving
distance in the EU fuel economy driving cycle. VW also points out that as soon
as the driver presses the pedal the cylinders will reactivate without the
driver being able to tell it happened. The cylinders also would not turn off if
the vehicle were being driven in a sporty manner apparently.
quote: The cylinders will be deactivated when the engine is operating between 1,400 and 4,000 rpm
quote: In my opinion, unless it's a sports car or truck, there's no reason for a vehicle to have much more than 100hp
quote: there's no reason for a vehicle to have much more than 100hp
quote: Ideal would be a small engine and the capacity for quite large power surges, even if small in duration (50 HP sustained, with surges of 120+HP for 10 seconds or so).
quote: 15 seconds may have been adequate in the days people saw cars attempting to merge onto the highway and actually moved over a lane to allow access. Now that rudeness and texting are the norm you risk your safety with anything that reaches 0-60 in more than 12 seconds.
quote: you gotta have something that can accelerate with aplomb
quote: Unless it's a sports car or truck, there's no reason for a vehicle to have much more than 100hp -- and otherwise only lends to a close friend's thought that his Mazda 6 is a super-car..
quote: Unless it's a sports car or truck, there's no reason for a vehicle to have much more than 100hp
quote: It may just be me, but who regularly drives past 4000 rpm unless racing or speeding..?
quote: The engine will run on 2 cylinders ONLY if between 1,400 and 4,000rpm AND the load conditions are satisfied. If you're trying to accelerate then the engine will use all 4 cylinders even if under 4,000rpm. There isn't just a sudden power surge at 4,000 when the other two cylinders come online.
quote: 3) It's less profitable for manufacturers to make automobiles that, given today's material and manufacturing improvements, wouldn't break so often anymore and would be inexpensive to fix if the complexity weren't increased.
quote: Your should understand why when the dealer tells you "30K miles is normal."
quote: That they actually believe that? Yes, I think they do.
quote: with a 70hp engine that was just capable of reaching highway speeds.
quote: My girlfriend years back had an '88 Plymouth Sundance that got 40+ mpg, even with an intake manifold leak losing loads of vacuum..
quote: Personally, I don't know why they don't go back to the 70s-80s concept of a light car with a 70hp engine that was just capable of reaching highway speeds.