[jecilop]

I'm new to an automatic of my own. I came across a general comment on a fuel tracking site about coasting and whether or not it helps your MPG.
I was wondering if anyone in these forums knows enough about the Ecotec engine in the 2011 Equinox to know if:

1) Is it safe to switch to coast when you know you'll be slowing to a stop no matter what the initial velocity is?
Personally, I've never just shifted from drive to neutral to have ever considered this although it seems like it should be ok.

2) Is this beneficial with this engine?

Below is the comment that made me wonder:
"Coasting to a stop in neutral with a modern manual (and in some instances automatic) transmission might not actually save you as much gas as keeping it in gear. Many modern engine management systems sense deceleration and negative load while the car is in gear and cut off fuel from the injectors, allowing the turning drive shaft to keep the engine going. Shifting into neutral while decelerating means the system has to keep the engine running with gas."

 

[gar187er]

if you anal, go ahead and go all out on hypermiling....

i dont think its worth it..... IMHO

 

[RIT333]

2) Is this beneficial with this engine?

Below is the comment that made me wonder:
"Coasting to a stop in neutral with a modern manual (and in some instances automatic) transmission might not actually save you as much gas as keeping it in gear. Many modern engine management systems sense deceleration and negative load while the car is in gear and cut off fuel from the injectors, allowing the turning drive shaft to keep the engine going. Shifting into neutral while decelerating means the system has to keep the engine running with gas."

According to what I have read, the above statement pertain to the controls of the Ecotec, and this shifting into neutral, while being illegal, also burns more fuel. IIRC

 

[bballr4567]

You want to keep it in gear. When you are slowing down and the car senses you dont have your foot on the it goes into DFCO, decel fuel cutoff.

Basically, it literally almost stops all fuel delivery into the engine. Its why our vehicles slow so much faster than others because its so harsh. In my G8 I can coast forever because its DFCO is really not that much but the I4 on our theta vehicles is.

Shifting to nuetral causes the engine to HAVE to stay running so it uses much more fuel.

 

[KCorey]

This is a very old idea whose time has come and gone. Many years ago it may have made sense but with newer (the last 30 years or so) transmissions this is not the case. Just about all automatic transmissions have only one oil (fluid) pump, the rear pump was eliminated possibly as a cost saving measure. So, if you coast in neutral the forward pump cannot supply an adequate amount of fluid to the rear of the transmission, and you will damage the unit. Always keep the car in gear. If you're approaching a stop (sign or light) you can save your brakes by down-shifting, and possibly save some gas.

 

[gar187er]

yea the crazies dont use neutral, they actually turn the engine off completely...

 

[mnussbaum]

Basically, it literally almost stops all fuel delivery into the engine. Its why our vehicles slow so much faster than others because its so harsh.

I believe there's a service bulletin for the 2010 models to fix this. My 2011 Nox coasts quite nicely.

 

[bballr4567]

I believe there's a service bulletin for the 2010 models to fix this. My 2011 Nox coasts quite nicely.

Yup, its because people complained about it. Im not overly worried and when I take it in to get the headliner fixed, the ECU will get updated.

 

[daequinox]

Keeping it in gear is better for autos, and also... one thing I want to mention is that it's okay to use up your brake life. Brake pads are cheap to replace.

 

[jecilop]

Thanks for the constructive feedback posts.

 

[Old Lar]

I have done some neutral shifting coasting and on some back roads (55 mph speed limit) with hills etc, I saw dramatic mpg increase. This was over a 300 mile road trip. I only did that when there was no traffic around and the roads I was on had little traffic. It is hard to do when there is traffic. The MPG increased by 4-5 mpg during that trip.

 

[auditman]

Watch the Tach, the rpms drop off in neutral, so even if the gas cuts off or back when decelerating in drive, at least you can coast further and get a little more mpg.