On Monday, May 16, 2016 at 11:29:32 PM UTC-4, Don Y wrote:
On 5/16/2016 8:10 PM, rbowman wrote:
On 05/16/2016 01:34 PM, Frank wrote:
Instantaneous readout on my new Subaru indicates I get 100 mpg going
down hill.

when I first got the ScanGauge I had it in instantaneous mode. I think the
injectors shut off completely when you're coasting. That mode isn't too useful
in town.

New cars play games shutting down cylinders when the power isn't
required.

My Odyssey *used* to do that but I've disabled it. Honda calls it Variable
Cylinder Management and most Ody and Pilot drivers hate it. There was even
a Class Action suit against it due to fouled spark plugs, failing motor
mounts and excessive oil consumption. That is in addition to the driveability
issues related to vibration, stuttering, delayed accelerating, etc.

Last year a guy invented what he calls the VCMuzzler. It is nothing more
than a resistor with Honda OEM connectors that you place between the
Engine Coolant Temperature sensor and the ECU. It fools the ECU into thinking
that the ECT is a few degress below the threshold required for VCM to
engage. He has worked out the resistance value such that it doesn't impact
the fuel mixture curve at low temps or cause a CEL.

The original version had only 1 inline resistor, but as more and more people
bought the device, it became apparent that different values were required
based on the ambient temperature of the environment. The 2nd generation has
a extra connector so that different value resistors can be tested. I've been
running with a 100Ω resistor for about a year and the only time VCM has kicked
in was when I was towing a trailer through the hills in 90° temps. The
engine would heat up while climbing and the VCM would kick in as I coasted
down hill. Once the engine cooled down a bit, no more VCM, so there was
no impact on the driveability.

The device has thousands upon thousands of miles on it all across the
country and users couldn't be happier. Many of us have had our cars
inspected with the VCMuzzler installed and there has never been an issue.
The fact that it is plug-and-play means that it can be removed for testing
if there is any concern that it is causing an problem but I have never heard
of an single issue and I follow the forum threads on it just in case.

This video is a short (1:58) install video showing the device:

https://www.youtube.com/watch?v=DewUNWlh1zU