Fuel economy, RPM and neutral with a 2016 AT

[tonyowen]

I wonder to what extent the computer meters fuel during deceleration to a stop, and whether forcing idle RPM by moving into neutral might improve fuel economy. And what consequences there might be in the long run to the transmission.

[Dubcee]

You would use more fuel in neutral than in gear because when you let off the gas, the car uses engine braking and cuts fuel to slow you down (0 gas used). You lose this benefit in neutral (gas is used to keep idle). It's also adding wear. Keep it in gear.

[CarLadyLisa]

The Skyactiv engines go into a neutral mode when at a stop as well. If you pay attention to your pedal when at a full stop you'll feel it kick back in gear. It helps with the lurching feeling that automatics are known for.

[tonyowen]

In the 2007 MT, the car indicates consumption of 2.4 L/100 decellerating in neutral at idle RPM, and 0 if it's in gear with your foot off the gas. In the 2016 AT, decellerating in gear with your foot off the gas, consumption also indicates 0. This cannot be taken literally because the engine is running and must consume some fuel. I interpret the zero as a computer programming oddity. The AT was not designed to be in and out of neutral in normal operation and I suspect there would be consequences in the long term. If I had the MT, I'd still use neutral as often as possible (easy to do without the clutch) to drop the RPM to idle and conserve fuel.

[Dubcee]

https://www.youtube.com/watch?v=6zzEtxJkC7Y