Automatic stop and so on the red light in the end which stop the fuel-saving?

The auto-stop car is waiting for the traffic lights in the end is the empty block or D-block. This is actually a commonplace problem, and I believe the owner's friend has seen a lot of information on the Internet, and many of the answers are correct.

But why did you read the articles, the owner of the friends will also feel confused? I think it may be because there is very little article, both analysis of the impact of machinery, and analysis of various situations of safety considerations. So, today, the small part of the pen again, try to answer the car friends of all kinds of worries and doubts.

Before unfolding the analysis, the small series first announced the answer, the correct way is "empty gear + hand brake". This is not purely mechanical considerations, but from a security standpoint, it is a must and the only way.

First, why must be "empty gear + hand brake"?

Analyze the possible risks of hanging D-block or P-block first.

In the first case, the traffic lights hanging D block, wandering around playing mobile phone or something fell on the ground to pick up, foot a loose car forward a leap, easy to cause rear-end collision. If the car happens to be the first in the queue, it is more likely to hit pedestrians on the sidewalk or bikes with a faster speed.

The second situation, in the case of rear-end, the first reaction is to loosen the foot brake, then the car will be further forward, whether the front of the vehicle is stopped or moving pedestrians, are not safe.

The third situation, hanging p block solves the first two cases of hidden trouble, but the p block has a transmission lock mechanism, moving the gear lever to the p block, the locking mechanism in the cable drive connecting the ball pin, the work pin sliding so that the locking pin pawl fastening the parking gear, thereby achieving the parking lock. If rear-end, the impact will directly affect the gearbox lock mechanism. If the damage is relatively small, can not be seen, then found that the insurance company does not compensate, the loss is greater.

In the fourth case, the car with the start-stop system is hung D-block. In the off state, even if the D-block, transmission clutch and gear is also in a detached state, so if the rear-end, there will be no risk of damage to the gearbox. But if the owner of a temporary tension to loosen the foot brake, the car automatically ignition forward, and appear similar to the first or second case of risk.

Summary: "EMPTY gear + hand brake", to solve the vehicle to maintain static and under the impact of external force transmission protection problems, although the action is a bit cumbersome, but safe and reliable. At the same time, "empty gear + hand brake" the benefits of fuel-saving, prevent slip slope, so that the driver's right foot to get a short rest.

Exception: AUTO hold+ engine Start-stop collocation, less go home block or keep in the D block of trouble. Traffic lights temporary parking directly put d, brake on the engine automatically start and stop involved in the stall, and then autohold intervene, to maintain the vehicle still. Need to move forward, click on the throttle, the vehicle starts, directly from the D-Block walk, no additional wear and tear gearbox, no increase in fuel consumption, more frequent D-file/n-file switching brought by the gearbox wear.

Second, purely mechanical considerations, whether go home block or maintain in the D-block have some negative effects, no one who is inferior, there is no way absolutely correct. We can say it in the form of gearbox.

(1) automatic transmission (at)

A. In the case of empty, the engine idling speed is low, the gearbox hydraulic torque converter speed is lower, in this case, the comparison of fuel-saving, engine jitter is also small. But in the D-block, due to the engine speed and torque converter speed difference, the impact of the shift will be on the clutch control unit such as the original device in the sliding valve box caused damage.

B. Hanging d gear brake, hydraulic torque converter is still working, the vehicle is more fuel-consuming, engine load, jitter large.

Second, dual-clutch (DCT)

A. In the case of an empty block, the DCT gearbox stops working and the fuel consumption is reduced slightly. When walking, from the air to the D-block, the same will have the power output and transmission mechanism coupling impact force, it is also wear.

If the low-speed walk when the short stop, the gearbox is in 2 block, this time go home block, and then into the D block, the gearbox from 1 to start work, this time the stutter sense and wear is more than go home block.

B. On the brakes, the gearbox is in low position, a loose brake, the engine output shaft and clutch plate hard connection (no torque converter double clutch gearbox), bring a relatively large impact, in theory will increase the wear of the clutch.

Third, stepless speed Change (CVT)

The CVT and at are similar in that the clutch is separated when the air is in, so there will be an impact to the D-block, which always maintains the D-block, the engine load is large, the jitter increases, and the fuel consumption increases.

Summary: Automatic transmission at the time of the traffic lights, regardless of the hanging or the D block will inevitably produce wear or other losses, of course, these losses are usually negligible negligible. From a safety point of view, in addition to the Auto hold+ Auto-stop car, all the automatic transmission form, waiting for the traffic lights, should be "empty gear + handbrake."

Automatic stop and so on the red light in the end which stop the fuel-saving?