Kelsen

I have searched the owner's manual (pdf form), and can find no mention of VCM (or even the word 'variable'). My vehicle is a 2014 RDX w/Technology package.

Does it have VCM? I have seen no indication (no mention even of icons/lights, nor did I see a light come on when on a trip that on which I would expect VCM to activate if it is there?

If it is somehow optional, is there a way to determine if my vehicle has this function?

Thanks.


RFT!!!
Dave Kelsen
--
"More than any time in history, mankind now faces a crossroads. One path leads to despair and utter hopelessness, the other to total extinction. Let us pray that we have the wisdom to choose correctly." -- Woody Allen

Brown13

Yes,it has VCM.You may notice a slight rumbling sound at about 29,39,49,59 mph,when driving on a flat stretch of road.Your mid display will show higher miles per gallon at that time.If You don't notice when VCM kicks in,You should not try to hear it.Because You will always hear it from that time. It becomes annoying to some people.

Kelsen

Thanks; I have done a bit more research, and I know that it is a part of the vehicle now. I now have to ponder if installing a VCM blocker would be staving off a potential problem, or if Honda has figured out a way to keep the oiling problems from happening.

I don't think the actual operation of the VCM will cause me any grief. I still wonder a bit why there is no mention of it at all in any of the manuals. Anyway, thanks again for the response.


RFT!!!
Dave Kelsen
--
Contra Felicem vix deus vires habet (Against a lucky man, a god scarcely has power).

MinnesotaRDX

Just a word of warning: I read several other reports of users who installed VCM primarily because of vibration. My RDX recently fouled a spark plug, causing an engine misfire, and has been burning oil since around 80k miles. Apparently VCM operation can have adverse affects on the vehicles piston rings. I'd recommend considering a VCM muzzler for the longevity of your engine as well.

egads

I am an active member both here (wife's 2016 RDX) and at the Odyclub (my 2015 EX-L Odyssey) I can tell you that, in the RDX,
the VCM system is just about as good as it gets. It is slightly better in the post 2016 ones (6 to 3 cylinders instead of the 6 to 3 or 4 of the 2013-2015) you can hardly feel or hear it at all. I would still highly recommend using a "muzzler" anyway. Just because you can't feel or hear it, does not mean it is not fouling spark plugs and burning oil. There were specific Honda engines with low friction piston rings where these problems were almost assured, a lawsuit and warranty extension. However, over at the Odyclub there have been some case of newer vans, not covered by the warranty extension, exhibiting the same fouled plugs. It tends to take until about 70 to 80K before issue show up.

Here is the currently best Muzzler unit(s)

VCMTunerII Advanced

S-VCM

Both easily found with a Google search. Both automatically adjust themselves, can be configured to have a shut off switch.

The tuner one will shut shut itself off in an overheat situation and show the actual temp on the instrument cluster gauge. It also shuts itself off when the engine idles for a while, allowing diagnostics without removal. Both of these units do require a wire to the battery. The cheaper ones do not, but do require that you adjust them to meet your climate. Those may allow the VCM to operate occasionally. No big deal unless the temp swings where you live and travel are great. I'm in SoCal and have a simple one with a dial, left it at the default, and have had not VCM engagement since installing. (The Odyssey has an "eco" light that indicates VCM)

Kelsen

Thanks, egads. That sounds very similar to what I had figured myself. Although my 2014 already has 117K miles on it, the Tuner will likely be a good investment for me.


RFT!!!
Dave Kelsen
--
Friends help you move. Real friends help you move bodies.

BLEXV6

My 2014 RDX has about 110,000 miles and no issues at all.

Al Dente

Does the use of a vcm muzzler decrease gas mileage?

Kelsen

Yes, it does. Anywhere from 1-3 mpg overall, depending on your use. (I haven't driven long with it, and haven't driven at all without it -- but I have read every thread on the forum which mentions it.)


RFT!!!
Dave Kelsen
--
Beleive what you want, but beleive me out of it.

fjpthree

I've been passively following this thread as I have a 17 RDX and an 08 Pilot. According to Wikipedia these model years have the VCM:

​​​​​​

Vehicles equipped with VCM[edit]

• 2003 Honda Inspire
• 2004+ Honda Elysion V6
• 2005–2007 Honda Accord Hybrid (JNA1)
• 2005+ Honda Odyssey (USDM) EX-L and Touring Models only (J35)
• 2006–2008 Honda Pilot 2WD Models only (J35)
• 2008–2017* Honda Accord V6 (except EX-L V6 6MT Coupe) *Starting with 2013 Model, VCM operation is 3- or 6-cylinder mode, no longer 3, 4, 6-cylinder operation.[2]
• 2009+ Honda Pilot (all models)
• 2011–2016 Honda Odyssey (USDM) V6
• 2013 Acura RDX V6
• 2013 Acura RLX *3 or 6 cylinder mode
• 2014 Acura MDX *3 or 6 cylinder mode
• 2015 Acura RLX Sport Hybrid *3 or 6 cylinder mode
• 2016 Acura TLX V6
• 2017 Honda Ridgeline

SO my question is two fold. Is this accurate and does a 2014 RDX have the VCM?

MinnesotaRDX

Yes. All 13-18 RDX's have VCM.

egads

I think the implementation changed in the cycle. The 2013-2015 engines would shut down 3 or 4 cylinders depending on conditions. 2016-2018 ones just do 3.

jjrphs

I think you mean will run on 3 or 4 cylinders...depending on conditions. The VCM was never programmed to drop 4 cylinders and run on 2...

egads

Yes, I guess I meant shut down 2 or 3, running on 3 or 4.

Powershow

I have a 2017 Acura RDX and a 2012 Honda odyssey. The odyssey has had problems with the vcm so installed a VCM muzzled and so far so good.
Mia the 2017 Acura RDX also prone to have issues because of vcm? Should I install a VCM muzzled?

egads

The 2016-2018 RDX have the 3-6 VCM that the 2018+ Odysseys have. They are less trouble, so it is your choice. Remember: the VCM saves very little fuel on an individual
basis, but having it on so many Honda models gets them better CAFE ratings. (Corporate Average Fuel Economy)

Alex Medeiros

The 2013+ RDXs don't really have issues with the VCM system. Occasionally there might be some due to lack of oil changes/maintenance, but I wouldn't worry about it.

egads

As I said above, the 2013-2015 RDX have the same VCM system as the Odysseys through 2017. Supposedly, in 2014, Honda made a change to the piston rings.
However, folks still have had burn plugs and misfire codes in those vehicles made after 2014. So if you have an RDX that is 2016-2018, it does have a different VCM
system. For those VCM Muzzling is probably optional. But if you have a 2013-2015, muzzling is highly recommended.
Keep in mind that RDX owners tend to put far less miles on their cars than Odyssey and Pilot owners. Issues tend to show up after 80k, sometimes not until over 120k.

Spaarky

I was wondering about that. Specifically because I have a 2010 Odyssey Touring with the VCM. I know the VCM has engaged when the ECO light comes on.

But I don't see any indication on the RDX that it's gone into VCM mode.
And I don't really notice the rumble/noise issue on the RDX. (I DO notice it on the Odyssey & it's got active noise cancellation.)