I read here:

http://www.topgear.com.ph/features/columns...uck-in-traffic#

Hi, Ferman!

I recently bought a Toyota Vios 1.5 equipped with a four-speed automatic transmission. I have a habit of shifting to neutral during stop-and-go traffic conditions and while waiting for the light to go green.

My question is: will this have a bad effect on my transmission? I feel like leaving the gear set to D during traffic consumes more fuel and might place additional stress on the brakes because it is trying to stop the car constantly. Is this true as well?

I used to drive a Lancer 1.6 equipped with CVT. I never really had a problem with the transmission despite doing the same thing. But I've read that CVT is different from a traditional automatic transmission, which the Vios has. I'm really wondering if this driving habit is good for my car or not.

Thank you very much for reading this letter.

Regards,

Dennis

Hi Dennis,

What you are doing is correct.

Quite a number of drivers, particularly the ones who picked up bad driving habits from other drivers who didn't know any better, often practice improper driving by not shifting to neutral when the car is not moving. While I would like to tell you that there is a good reason (under normal circumstances) for keeping it in D and stepping on the brakes at a stop, I can't. It's mostly born out of laziness and improper training.

As you have correctly surmised, the engine does consume more fuel and you do wear down your brake-system components more when you leave your transmission in D or Drive while the traffic light is red or when you’re idling and waiting.

With automatic transmissions, the engine is energizing or driving the transmission to move in the direction of the gear you've selected--forward or reverse. When you keep it in gear, you are telling your vehicle to move; when you're on the brakes, you're preventing motion. You're unnecessarily and slowly raising your automatic transmission fluid, wearing out your transmission clutches, and consuming more fuel because you're on the brakes to keep the car from inching forward. You're also unnecessarily wearing down and heating up your brake pads. By simply shifting to N or neutral there would be no need to apply the brakes with the amount of force required to resist forward motion.

If you notice all of the above result in unnecessary wear, all of which increase the cost of operating and maintaining your vehicle. It's also a very unsafe practice as if you happen to accidentally lift your foot off the brake, you will most likely get into an accident.

While we're on the subject of automatic transmissions, it is also a very bad habit to shift into P or Park when you're at a stoplight. Numerous drivers have adopted the practice as well and, quite frankly, it is also an accident waiting to happen apart from slowing damaging a different part of your transmission, which will eventually lead to the a different sort of automatic transmission failure.

It won't matter if your car has CVT or the conventional multi-speed automatic transmission. Shifting to neutral under most normal conditions is good practice.

Best regards,

Ferman Lao
Tech editor

Leave a car on a flat road, shift the gear to D, forward gear engaged and the car will move forward. A car has 4 wheels, whenever being placed uphill or downhill, depends on the moving direction, it will move faster or slower. A car carries weight and has an engine. On the other hand, if we put our hand on a table, our hand does not have wheels, nor engine. So I disagree there is no friction. The friction applied by the brake pads offset the force vehicle moving forward, therefore it is not moving, under D gear.

I am amuse by some people who are so particular on taking care of their cars. My POW is that, car is a liability, and subject to wear and tear. On the roads, how many cars have you seen are >10 years, >15 years or even > 20 years. I believe most of these major parts, should last at least during the ownership of the vehicles. A car is designed in a way to wear out, therefore IMHO, it is good to know but no point argue over this. If it is something very crucial, it will be told and mentioned. Too bad if you do a search, there are 2 schools and no definite answer. To take care of transmission, it is not only D and N, the way the driver maneuver, maintenance, design and etc. have more influences.

This post has been edited by gold member: Dec 30 2013, 03:40 PM