while driving and than stopping at a red signal is it recommended to shift the transmission from 'D' to 'N'?

NO!!! A transmission is designed to do this on its own. When you do this, you are moving the manual shift valve, and wearing it out too. Why would you want to do something that causes double wear on your transmissions valve body? You do know how close reverse is from neutral, don't you? That's right, one click away, and if you moved it that one click too far, well....... you know the answer to that one. When you go from neutral to drive, it places a surge on the hydraulics, and some of the valves. When the transmission downshifts on its own, this surge is cushioned by springs, thus is much easier on the valves than the manual surge of going from neutral to drive. In other words you will be putting more wear and tear on the transmission by constantly changing gears, than you would if you let it do the job by itself. They are designed to be put in drive (D) and left there until you stop, as in being ready to either back up, or park.

A certain amount of slippage is built into the torque converter, and produces heat. If you are going to be sitting for an extended amount of time, then use N or P so the transmission will run cooler. When in N or P the torque converter is not working, and doesn't produce heat. A lock-up torque converter does the same thing as putting the vehicle in direct drive when you reach the speed of about 45 mph. It engages and the torque converter no longer produces the heat from the slipage. When you put your foot on the brake pedal the torque converter disengages, and begins to slip heating up the fluid. The built in cooler in the radiator keeps the fluid at a safe temperature. So when you are sitting still the transmission makes heat, and if you are sitting for any period of time this heat is not good, so use the N or P.

Glad to help. Good Luck!!!

It does depend on what the type of car is but and i am a car frick but never heard of a GMC LST. Leave the car in d is ok if it is a modern car it will usally go into N While in drive and will stop trying to move. The next time you drive see if when you take your foot of the accle if it is smooth or not. if not while than i would put it in to N. If you going to be more than about 1 minute i would put it in N But yo can leave in D and does not Damage your car

You can leave it in "D" forever and it won't harm the car at all. It's designed for that.

Shifting into and out of "D" means the transmission is shifting, engaging and disengaging the clutches and bands inside the transmission. Which wears them very slightly. If you did it at every light, it could add up.

You're not going to save any gas, the engine/tranny computer already knows how to do the right things to save gas.

Dot regulations state that you are not to take the car or truck out of gear . At a stop light or going down a hill it should remain in gear at all times except when shifting from one gear to the next.

If it's at night and you know you'll be there for a minute or two, shift into park. That way, the person behind you doesn't have to put up with your brake lights on the whole time.

No harm in keeping it on D, I tend to do that. For people not used to automatic transmission, it would be better to resort to P while on a red signal, just in case they accidently take their foot off the break while still in D.

Cheers.

If you are stuck waiting on a train or something then yea i would out it in park. But not neutral when waiting on a light maybe p if its a lonnnng wait!

But i disagree with the other. If you don't shift to N, your engine is against your brake. this is not good to engine, brake, transmission

no

u can keep it in 'D' .