Author Topic: VCM & ethanol  (Read 4900 times)

Offline DougA

  • Newbie Gearhead
  • *
  • Posts: 2
    • View Profile
VCM & ethanol
« on: April 22, 2011, 11:20:56 AM »
I have a 2005 Honda Odyssey EX-L with the VCM engine  (variable cyl ) which will shut off 3 of the 6 cyl when crusing  (newer models have 2-3-4 shut off I believe)
I see that the current release of software, there is an update for 'Injector Cutoff detection'  which is good, as this engine will also shut down all injectors when coasting.
Question is, will it also correctly report gas usage while 3 cyl are shut off ?
This is a serious shortcoming in the ScanGuage II, does UltraGuage have the same issue ?

Also, buried way down in the FAQ is a little comment about "The use of ..., or fuel containing ethanol ... will alter the MPG ..."    The spread of ethanol mixed fuel is everywhere I go,  does this mean the UltraGuage isn't very useful for this purpose ?  (Monitoring fuel comsumption)

Offline UltraGauge Admin

  • Administrator
  • Sr. Member Gearhead
  • *****
  • Posts: 364
    • View Profile
Re: VCM & ethanol
« Reply #1 on: April 22, 2011, 11:37:36 AM »
Does the engine have a MAF sensor?

Ethanol has less energy density per gallon and is a poor value.   UG can be calibrated and will compensate for the Ethanol, but if you then fill up with non-ethanol, your MPG will be off.  Stick with good old Gasoline and avoid the trouble.

Offline DougA

  • Newbie Gearhead
  • *
  • Posts: 2
    • View Profile
Re: VCM & ethanol
« Reply #2 on: April 26, 2011, 01:28:33 PM »
What you say is true, but, there isn't any choice in the matter, all stations sell only ethanol enhanced fuel.

However, I'm really more interested in the VCM mode, does the UG correctly show fuel usage when cylinders are shut off ?   In the case of the 2005 Odyssey VCM engine, that's 3 of the 6 get turned off.

Offline UltraGauge Admin

  • Administrator
  • Sr. Member Gearhead
  • *****
  • Posts: 364
    • View Profile
Re: VCM & ethanol
« Reply #3 on: April 26, 2011, 01:34:44 PM »
, does the UG correctly show fuel usage when cylinders are shut off ?   In the case of the 2005 Odyssey VCM engine, that's 3 of the 6 get turned off.
If your vehicle has a MAF sensor, then yes UG will work fine.  If it has only a MAP sensor, then UG has no way to know when its a 6 versus a 3 cylinder, which is necessary with MAP.