[Reddevil]

I installed mine a couple days ago. Been averaging 20.1 city, and just did 50 miles on highway @75 cruise control, averaging 24.2

 

[se93]

Greetings to all.

Are there any downsides to deactivating the VCM?

Curious as I purchased a 2014 Pilot Touring and have been browsing through this very interesting website community absorbing new details with respect to this vehicle.

Regards,
Mark

 

[ryebread]

The only downside I've noticed is reduced MPG since you're using all 6 cylinders at all times.

Update on my MPG. I drove this past week from a full tank as if it were the last tank of gas on earth and was able to get my average up from 12-14 mpg to around 16 mpg.

My check engine light also came on with a P0420 code and my short term fuel trim also clearly got worse (see attached), where both banks are now idling at -12% to -15% from the other week when they were idling in the -4% to -6% range. @WiiMaster @dr bob I'm planning to replace my upstream O2 sensors this weekend to see if that helps out. What I can't figure out is why both banks got affected at the same time. If one of the O2 sensors was bad, wouldn't I expect to see issues in only one of the banks? What are the odds that both upstream O2 sensors went bad at the same time?

 

[WiiMaster]

There are a lot of things that can cause a P0420/P0430 (though the most common causes are O2 sensors or the catcon). Have you ensured you don't have any issues like a torn intake hose or anything like that?

 

[ryebread]

The same P0420 code was thrown a few weeks ago and turned out I did have a torn intake hose. Tear was pretty big in an area I didn’t notice. Bought a new one and installed, cleared the code, and it didn’t come back on. Then just came back on again 3 weeks later so assuming it’s a different issue.

I don’t have new O2 sensors on hand and Autozone and Orielly are twice as expensive as online for OEM, so just ordered from Rock Auto. Had a can of Seafoam Spray and just ran that through the engine hoping that’ll buy me some time. Cleared the codes and the engine seems to be running a bit smoother plus short term fuel trim has come back down to -5% range.

Still planning to replace the upstream sensors when they come in.

 

[WiiMaster]

Also try driving with a lead foot on the highway for a bit to help burn off any deposits that could be contributing.

 

[ItsCorn]

Carrying the bigger tires thought a bit further -- larger diameter tires affect the odometer reading, displaying fewer miles than it will with stock diameter tires. If you are watching the onboard mileage display, it will certainly show poorer fuel consumption numbers with taller tires. Tire Rack offers some handy data for lots of different tire brands. Look hard at the "revolutions per mile" numbers for original vs. your installed replacements, and use that to determine an odometer correction factor, the ratio of original revs/mi to new tire revs/mi. Adjust your calculated MPG numbers by that correction factor, and you'll be a bit closer to the truth.


----
TL;DR --
My vintage Garmin GPS unit has options to track miles driven along with some other critical data like max and average speeds between resets. If I had larger tires installed, I'd grab that data and compare it with the speedo and odometer readings from the car itself, and get an idea of a correction factor to apply to each. I find that the readings from the car are about 6% optimistic for both. Translated to real life, that means the car is travelling about 47 MPH when the speedo displays 50 MPH. ODO similarly logs more miles than what shows on the GPS, by a similar factor. Most decent smartphones can use a GPS map application that displays speed, something you can use to at least get an idea of how accurate your displayed speed readings are while driving. IIRC the allowable error from the factory is 5% with new tires on it, and that error will change with tire wear and also inflation pressures.

While we don't generally consider the Pilot to be anything close to "aerodynamic", aero drag is a force to consider. The coefficient of drag, C-sub-d, is the relative efficiency of the shape as it travels through the air. To estimate total aero drag, you get to multiply that drag coefficient by the effective frontal area of the car. With the car raised up, that effective frontal area increases. So the total aero drag numbers go up too. Remember also that friction losses escalate at the square of the increase in velocity. That includes aero and mechanical losses. With taller tires and driving at an actual NN MPH, those losses will be 4x at 2 x NN MPH.

Well holy shit! After reading the first post, I was about to give my VERY unscientific version of this...glad I read through some of the posts. What a well thought out response,I've never seen the actual calculation...thank you Dr. Bob!

As someone who's lifted/leveled my last three trucks, and added substantial weight and size through various wheel/tire combos, I would think that your (ryebread) MPG drop is being affected in this area, more than any other. Assuming you're using the BF Goodrich Terrains in a 235/60/18 setup (your instagram pictures are great btw, nice looking rig!), they clock in at 35 lbs per tire. The original Forteras (that I'm assuming they used in MPG calculations back in 13') were 30lbs a piece. 20 lbs shouldn't net a substantial difference, especially with width/circumference being the same.

The 2" lift would appear, to me, the biggest culprit here. It would be even worse if you have an oversized tire.

 

[TechBill]

I have had VCM Muzzler installed for the past 3 years on my 2012 Pilot Touring 4WD and usually end up getting around 12-14 mpg combined between highway and city driving in Los Angeles.

What MPG range is everyone else on here getting with VCM disabled?

It feels like my MPG is low for what I probably should be getting and am trying to go about figuring out how to improve.

Additional Info on my Pilot:

• It has a 2" spacer lift on it
• 2 small oil leaks from the rear main seal and oil pan, which result in 1 drop on the driveway per month, so not a big leak.
• Spark plugs were replaced <2 year ago (Denso Iridiums) and just inspected and cleaned last weekend. No oil fouling or oil in tubes or coils.
• PCV valve was replaced when VCM Muzzler installed.
• Have not replaced EGR yet but have a new one on hand. There are no indications that it's bad.
• Had a check engine light come on last weekend (P0420) which I think was due to a pretty big tear that had developed in the air intake boot, which I promptly replaced, and seemed to fix the issue.
• The engine runs and sounds fine with no knocking or rattling.
• Air filter is new.
• Here are pics of my pilot: https://instagram.com/familykuruma?igshid=YmMyMTA2M2Y=

Thank you in advance for sharing the MPG you all are seeing with VCM disabled!

I noticed in Instagram that you are running Carplay in your Pilot. May I ask what device are you using to make this possible or is it the Navtool ?

 

[bzwyatt]

My '09 at 177k is the same as everyone else, basically.

Have P0420/P0430 off and on. Last year I replaced plugs/cleaned MAF/replaced PCV/changed air filter/tube. Always use synthetic oil, and drain/fill ATF a couple times a year, only Shell/Chevron/Costco gas.

Best thing for the C/E light is driving on the highway, usually I'm only going 10 miles per trip at most, a lot of smaller trips in the city maybe a mile or two at most.

I have somewhere around 16-17mpg. If I drive on a long trip and don't go 85mph, I get around 25.

I also got new tires but still need to have an alignment done, the rear camber needs to be repaired.

 

[Alc50]

I have had VCM Muzzler installed for the past 3 years on my 2012 Pilot Touring 4WD and usually end up getting around 12-14 mpg combined between highway and city driving in Los Angeles.

What MPG range is everyone else on here getting with VCM disabled?

It feels like my MPG is low for what I probably should be getting and am trying to go about figuring out how to improve.

Additional Info on my Pilot:

• It has a 2" spacer lift on it
• 2 small oil leaks from the rear main seal and oil pan, which result in 1 drop on the driveway per month, so not a big leak.
• Spark plugs were replaced <2 year ago (Denso Iridiums) and just inspected and cleaned last weekend. No oil fouling or oil in tubes or coils.
• PCV valve was replaced when VCM Muzzler installed.
• Have not replaced EGR yet but have a new one on hand. There are no indications that it's bad.
• Had a check engine light come on last weekend (P0420) which I think was due to a pretty big tear that had developed in the air intake boot, which I promptly replaced, and seemed to fix the issue.
• The engine runs and sounds fine with no knocking or rattling.
• Air filter is new.
• Here are pics of my pilot: https://instagram.com/familykuruma?igshid=YmMyMTA2M2Y=

Thank you in advance for sharing the MPG you all are seeing with VCM disabled!

Combined highway and city.
2015 87,000 miles

 

[brybo86]

14.6mpg for me last fill-up.

90% city driving

10% suburban

 

[DrummerBoy523]

I have had VCM Muzzler installed for the past 3 years on my 2012 Pilot Touring 4WD and usually end up getting around 12-14 mpg combined between highway and city driving in Los Angeles.

What MPG range is everyone else on here getting with VCM disabled?

It feels like my MPG is low for what I probably should be getting and am trying to go about figuring out how to improve.

Additional Info on my Pilot:

• It has a 2" spacer lift on it
• 2 small oil leaks from the rear main seal and oil pan, which result in 1 drop on the driveway per month, so not a big leak.
• Spark plugs were replaced <2 year ago (Denso Iridiums) and just inspected and cleaned last weekend. No oil fouling or oil in tubes or coils.
• PCV valve was replaced when VCM Muzzler installed.
• Have not replaced EGR yet but have a new one on hand. There are no indications that it's bad.
• Had a check engine light come on last weekend (P0420) which I think was due to a pretty big tear that had developed in the air intake boot, which I promptly replaced, and seemed to fix the issue.
• The engine runs and sounds fine with no knocking or rattling.
• Air filter is new.
• Here are pics of my pilot: Login • Instagram

Thank you in advance for sharing the MPG you all are seeing with VCM disabled!

Disabled or Enabled?
Without the Muzzler - we were getting 17mpg/21 hwy.
With the Muzzler installed - we are only getting a small bump to about 19-20mpgs. I get about 23-24 on the hwy. It doesn't seem to help much in the mpg area for us - but for me, just making sure all 6 cylinders are engaged is worth more to me than the mileage.
FYI, we had the EGR valve repaced due to a CEL that kept popping pre-VCM

 

[WiiMaster]

It doesn't seem to help much in the mpg area for us

Disabling VCM is not supposed to be a trick to increase MPG. In some cases it can but usually you lose 1-2 at most.

 

[brybo86]

I just reset my trip and it calculated 23.8mpg over 80 miles
Half driving was 75 mph on freeway and half was a 2 lane divided highway 60mph with intermittent stop lights.

Stop and go city driving in winter? Like 15mpg.

 

[sidefly]

2012 4wd 88k miles - Now averaging 21 @ 80 over 250 miles on the same closed track I've driven since new. Never got over 18.8 in the past. And so smooth now, I'm impressed.

 

[Jbrharris]

19.7 MPG

 

[mmmmark]

2012 2wd 150k miles.

Put on a muzzler at about 130k miles. I get about 16 normal driving in and around town. Just drove 750 interstate miles with speeds 75-85 mph and could not break 17.5. That was disappointing, but this is not our trip vehicle (needed extra room for this trip).

Before muzzler on same route with same speed I would get 20-24.

Since this is my work vehicle I’m still glad I installed it for how it drives in town, but for highway it stinks.

BTW, when I changed plugs at 110k the plugs looked pristine so the VCM did not seem to be a detriment at that point to the engine.

 

[dr bob]

Grabbed the logbook ---

Mileage early in life, no muzzler, L.A. basin (Glendale), and a rather circuitous last-mile to the house, calculated mileage ranged from 17 to 24 mostly depending on trip distance.

With the VCMuzzler and the move to central Oregon nestled in there, in-town delivers 19.8 to 23.4. No more uphill slog to the bungalow on the bluff in Glendale, so shorter trip economy improved a lot. Extended rides to civilization show 21-26. Again, all calculated from the odometer and the pump gallons. The calculated economy on the console display is optimistic by 3 to 5%, so the log shows only the at-the-pump calculated miles.

The right foot on the throttle, followed by brakes, wind/drag and gravity, are the contributors to fuel economy. Mrs dr bob gets about 3 MPG less than I do, same car, solely because she pushes harder on the pedals. We don't get there any faster, just spend a little more on fuel. Drive like you have raw eggs in your shoes, keep engine revs below 2500, allow the engine to run in the highest possible transmission gear, and drive like you have no brakes and no insurance. Mileage will improve.

 

[ryebread]

18-20+ MPG I'm seeing from a lot of folks is quite high and nothing close to what I can get, even with extremely soft foot and drafting behind big rigs in the right lane. Best I can do is 14-15 MPG avg per tank.

I replaced both the up and downstream O2 sensors on front and rear precats, which seemed to keep CEL off and no more P0420 code for now. My hope is that the precats aren't too toasted from having VCM enabled from the prior owner for 2/3rds of the Pilot's life so far.

I do have slightly larger than stock tires on stock 17" steel wheels, which could be contributing to the MPG issue. Instead of the stock P235/60R18 tires for the Touring model, I'm running P265/65R17 on the LX steel wheels. The tire circumference is ~4.8% larger, so that would put the 14-15 MPG average I can do at best at around 14.6-15.7 MPG, so still not great.

My fuel trims don't look terrible, but I'm considering replacing all my injectors since they're all still original and 11 yrs old (175K miles) at this point. Does anyone have experience replacing these preemptively with any gain?

 

[dr bob]

<...>
I do have slightly larger than stock tires on stock 17" steel wheels, which could be contributing to the MPG issue. Instead of the stock P235/60R18 tires for the Touring model, I'm running P265/65R17 on the LX steel wheels. The tire circumference is ~4.8% larger, so that would put the 14-15 MPG average I can do at best at around 14.6-15.7 MPG, so still not great.
<...>

To make a fair comparison of fuel consumption with the larger tires, you'll want to consider that larger diameter in your miles-driven/gallons consumed mileage calcs. If your tires are 4.7% larger diameter, multiply your odometer miles by that same 1.048 factor before dividing by gallons purchased. You've already worked out that math, so this is more for others playing along at home.

Things I notice in my casual driving-around: Most Economical Cruise (MEC) velocities are about 39 MPH and 48 MPH. These are gears 4 and 5 minimum speeds to get the torque converter to lock up. Once the converter locks at about 48MPH, it will stay locked up down to about 42MPH unless load demand (read: pressing on the skinny pedal) wants a lower gear (higher numerical ratio) to avoid high-load low-speed 'lugging'. I'd be very happy if we had a 'Economy' shift profile available with a higher load-demand needed for that drop-out. Unfortunately we don't. ;( Still, focusing in getting the transmission to highest possible gear and converter locked and maintaining that condition will have a very large impact on total consumption. Related: Our 'normal' drive into town from here includes a 45MPH rural road that drops to 35MPH as it reaches civilization such as it is. I could stretch those to 48 and 39MPH respectively. That's a northbound (prevailing downwind) trip that also drops a total of about 100-150' altitude over that distance. The trip computer shows mid-30's MPG for the ride north, but drops to 21-22 for the ride home on the same road. Moral: Always drive downhill and downwind for best fuel economy.

Tangent but maybe interesting: The EPA 'drive cycle' for fuel economy has the highway portion of the test between 48 and 54MPH IIRC. Manufacturers like Honda carefully select top-gear ratios to generate the best consumption numbers in that range. Your larger tires move the effective highway MEC numbers slightly higher (by 2-3MPH), which will help you at 55MPH actual but keep you out of converter lockup until 50MPH actual, with drop-out now 45 MPH and the PCM 5% more sensitive to load increase in that actual 45-50MPH range. If that speed range is closer to what you actually drive, the taller tires may be helping. I haven't done a full analysis for average speed while driving for the Pilot, but on my primary summer car that number is about 30MPH. That includes moving and stopped time while the engine is running. Top gear in that one with 2.54 'drag race' final drive is RPM-limited (no overdrive...) to 195 MPH around sea level, and altitude/air density limited here to low 180's. MEC is about 40MPH in top gear, where it feels like a waste to have the engine running at all. Low to mid 20's at sub-80MPH cruise, drops to 8-10MPG by 150. Room for two sets of clubs and weekend luggage with rear seats folded, but not much more. I have a 2.20 final drive set that does better on gas at higher super-legal cruise speeds, but exacerbates the altitude penalty. No free lunch, unfortunately.