engine braking vs neutral coasting

Hey Everyone,

I drive a 2013 Golf R Stage 1+. My daily commute consist of a lot of hills going up and down to work. Some days I just like driving nice and easy with the R and was wondering which is better for gas savings on a daily basis. I read online that some cars are going into vacuum when you engine brake which uses no gas at all and wasn't sure about the R. I know in my 370z, I got better gas mileage coasting in neutral rather than engine braking. So my question:

When travelling down a large pretty deep hill, are most of you engine braking down the hill or neutral coasting while applying the brakes when needed to control the speed. My goal here to save gas as a priority. I don't care about the duration of length of wear and tear on the brakes from more use.... again priority here is saving gas.

Can anyone enlighten me?

Thanks,
Ryan

from what I gather on vortex, this seems to be the most logical answer:

skibum525 said:

Coasting in neutral your injectors are still firing to keep the car running. Coasting in gear the fuel injectors are closed, meaning better mpg :thumbup:

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coasting down a huge hill, leave it in gear 100% for more MPG savings. If the car is slowing down that hill and you could go twice as far in neutral, well then neutral would be your choice. You have to play around with it, took me about 6 months to find the sweet spot on both my MKV (6-MT) and MK6 (DSG), though DSG makes it pretty brainless.

Try your different scenarios and compare you round trip results from day to day. Good luck!

This has been discussed ad nauseum in other threads. When engine braking, the computer shuts off 100% of the fuel to the cylinders. The car burns absolutely zero fuel. When coasting in neutral, the car is at idle and burns fuel at a rate of about .25-.30 gallons per hour. Engine braking will give you the best mpg while going down the hill.

Guys, great information. I know this topic has been discussed all over the internet, not just on these forums. I was looking for specifics for my vehicle as I couldnt find a direct answer when searching as lots of peoples' responses were opinions. So looks like Ill engine break down a hill if I'm coming to a red light or where I need to slow down and if I need to pick up speed, Ill neutral coast to increase MPH coming out of the hill.

Thanks alot everyone!!

If you're on the highway its a bit different though.

For max MPG on the highway here's what I suggest:
-No AC
-Windows closed
-Keep it around 65 MPH. Seems to be a sweet spot.
-Slightly faster on the downhills. I mean, just enough that you have sped up by a few MPH at the bottom.
-Constant throttle uphill, or slowly back off the throttle. You'll be going a little bit slower at the top of the hill.

The idea is keeping momentum in this case. Use the car's weight and momentum to gain speed with minimal fuel usage going downhill, and carry that speed through the uphill.

Best I was able to do was right around 38-39 MPG coming home on a 3-hour highway ride from DC to Philly.