Does non-moving A/T car consume more fuel if...

[ruelsdcz]

guys....additional info lang po from www.wikihow.com.

It is not necessary to put the car into Park or Neutral every time you stop. However, if you are stopping for a considerable amount of time, you may want to put the transmission into Neutral (N) or Park (P). Neutral allows you to shift back into Drive quicker, but you may need to keep your foot on the brake, depending on the condition of the road. Park will usually allow you to take the foot off the brake. Either one will allow the engine to idle at a more fuel-efficient rpm, and put less strain on the brakes and the drivetrain. However, repeatedly shifting in and out of Neutral and/or Park will strain the transmission.

[Jun aka Pekto]

errr...just to add to the options - does anyone shoft to "park" (P) while in traffic and the engine is running? what happens here and what implications does this have to the drivetrain?

That's what I do if the traffic doesn't move for a long time. Sometimes, I'll even turn off the ignition.

I've replaced brakepads (2 at a time) on our 1995 Ford Contour every ~4-5 years. But, I haven't had repairs or replacements yet for the A/T tranny since I bought the thing in 1994. it's been mostly ATF replacement. I've also driven the car aggressively for much of its lifetime. So, it's durability is quite surprising (for a Ford tranny).

Compare that to replacing the clutch every ~5 years for a Nissan Pulsar and Plymouth Laser. Brakepad replacement was about the same interval.

The 1997 Dodge Grand Caravan did have major A/T tranny repairs in 2004 and ended up with a replacement tranny. But, I think it was mostly due to extended long-distance driving rather than stop and go traffic. Our extended warranty covered it. So we didn't have to spend a single cent.

Add: As for N.... It's only use in my book is when the car's being towed.

[javauser]

i actually read about this topic from an official Honda newsletter a couple of years back. it says that it doesn't really matter. It does not consume more fuel either way. however, it emphasized that you cannot place it in Parking mode while your car is running. Since this came officially from Honda, I assume the statement is reliable. However, I am not sure if this applies to other car manufacturers as well.

[eyshmechanic]

as i mentioned in another thread about a/t i do shift to neutral during long stop. if you are on d or p instead of n during long stop, the torque converter is in stress. coz inside it parang may dalawang electric fans na magkaharap, one is connected sa engine which is running and the other sa tranny. so kung pigil yung fan na naconnect sa tranny and the other is umiikot there's friction building up between them thru atf which translate to heat. but sa neutral iikot lang sila pareho kaya walang stress.
haay sana tama ako he he!