New Volkswagen Engine Deactivates All Four Cylinders To Save Fuel
Volkswagen really is doing everything it can to reduce its environmental impact in the wake of its persistent diesel-related troubles. Its latest 1.5-litre turbocharged petrol engine actually shuts down all of its cylinders when you lift off the throttle.
There are two versions of the new 1.5 Evo engine, with 148bhp and 128bhp. The more powerful one uses technology similar to that which we’ve already seen in various VAG products, where half of the engine’s cylinders – two, in this case – shut down, but it seems that in this case it’s only when the driver lifts off completely, not under light throttle loads as well.
But the 128bhp model, which will arrive later this year, actually stops all four cylinders completely, eliminating engine braking completely and allowing drives to coast long distances without using a drop of fuel. Touching the brakes will reactivate the engine, and although we’re waiting for confirmation on this, it’s likely that dipping the clutch will do the same. The tech stops the engine in a decoupled state, so the car can simply glide along, unpowered.
VW says that the engine will go to the Golf first, but could be transferred to other models in due course. The 128bhp motor will slot into SE- and SE Navigation-spec cars, while the 148bhp upgrade will grace the GT and R-Line trim grades.
Performance figures for the lower-powered Evo unit haven’t been released yet, but 148bhp Golfs will be able to combine 55.4mpg and 116g/km with 134mph and 0-62mph potential in 8.3 seconds. Peak torque of 184lb ft will be yours from just 1500rpm, VW says, making it flexible as well as clever.
Comments
It is an old trick but in modern packaging. If you’ve driven an old car with carb, without servo and without steering wheel lock, you’ll know that you can shut down the engine completely and coast down the hill. You can’t do that in a modern car because you’ll lose your brakes and you can damage some of the electrical components. If VW system is working like described above it will be un-efficient compared to that old trick. There is no point of starting up the engine when you put the brakes on if you want to save as much fuel as you can down the hill. It will be way more efficient to backup the Servo unit in some other way than starting the engine to ensure that the car will have brakes. Maybe they just left space for EVO 2, which will cost more of course.
You’ve got it wrong man, first the engine is always rotating but the valves are closed and it doesn’t inject any fuel, but since the engine is still rotating the oil, coolant and air pumps are still working therefore the brake assist is working too, and when the engine “starts” back up, it doesn’t mean it’s injecting fuel, it just means the valves will come back to their normal operation to create the engine braking effect again and help with the brakes.
That’s actually very efficient, it’s just not well described in the article ;)
If we had that electric valve system that koenigsegg is developing you could just leave the exhaust valves open when coasting so the engine isn’t fighting compression, sure it’s not the same as stopping the engine completely but should be alot faster to switch on and off
You mean closed, leaving valves open is way less efficient than closed because when the valve are closed the air compressed by the pistons pushes back with equal force used to compress it plus friction loss of course but if you leave the valves open the pistons will just suck air in and instead of using its energy to push back the pistons it will just pump it out and then you add friction… so closed valves is the most efficient way therefore VW tech will work fine without adding to cost and complexity of the Freevalve system :)
Up next: the car automatically ejects the driver to save weight and therefore fuel when coasting
car be like:
Prius did it first
Might ask my dad to upgrade
This is getting out of hand. Do they not realize the best way for Volkswagens to use less fuel is if they stop making them!
Cut their emissions to zero that way.
I’m actually getting scared that when I do actually get a license every car will be electric.
The old cars will be arround. How old are you?
Sounds good, but that’s awful on the engine itself.
correction
Deactivates power to the wheels to create more emissions
vw should make check engine deactivation instead of this ….