Use neutral when idling?

My dad insists that this helps preserve the transmission, and I’ve always done it when waiting at a light.



But does anyone know if this really helps?



Thanks

Certainly doesn’t make any difference with an automatic. With a manual, it could save throwout bearing wear if it’s a particularly long light. If it’s less than about 20 seconds, though, I don’t usually mess with putting it in neutral.

With a standard transmission yes you’re supposed to sit in neutral, foot off the clutch. When the clutch is depressed for a long time the throwout bearing starts to get worn.

This question again?! We get it often.

With manual transmission, shift into neutral rather than depress the clutch the entire time. With automatic transmission it hardly matters. You will get a difference of opinion however, so you can do it either way as it pleases you. Just don’t listen to the know-it-all who asserts there is only one correct way.

It’s no big deal. However, when the car is cold it warms up the automatic transmission quicker when left in gear. When warm, I use neutral at railway crossings and other long waits. But mostly to save my muscles.

With an automatic transmission, the linkage between the engine and the wheels gets stressed each time you put the car in drive. It won’t make a difference in the short term, but over the life of the car, you are better off leaving it in drive and letting the torque converter do its job.

With a manual it’s definitely a good idea, as described by others. With the clutch in the throwout bearing is “loaded” axially by the springs in the pressure plate assembly. That causes faster wear than letting it rest in the “unloaded” position.

With an automatic it really doesn’t matter. Loads between the engine and drivetrain, whether the constant load of leaving it in gear or the minimal “shock” of reengagement are easily absorbed by the torque converter, a fluid coupling device. However, if your dad has an automatic and prefers to do this, I say let him. It isn’t important enough for you to be trying to get him to do it your way.

Depending on what kind of car it is, it may actually use more fuel to put it in neutral.