| youbetcha |
Can someone actually tell me what the distinction is between the "VTEC" engine used for most pilots before 2009 and the "i-VTEC with VCM" engine used in the 2006-2008 2wd and 2009- ?
Here's what I've read.
"VTEC" engine has always meant "variable valve timing and emissions control" but I've been reading that the "i-VTEC with VCM" uses the valve mechanics for cylinder deactivation, but the trade-off is that the engine in fact does not have "variable valve timing and emissions control."
So, in other words, the "i-VTEC" does not have "VTEC".
NOW, I have an "i-VTEC/VCM" engine, and I ran it up the tachometer. 4500 RPM came and went and nothing special happened. Hmmm.
So this may be true, and I guess if you're going to go for gas mileage that is fine but isn't having the acronym "VTEC" on the newer engine at least a little misleading? |
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| VettePilot |
I can't tell you about all years, but the 2006 Pilot with i-VTEC is only cylinder activation/deactivation -- VCM.
The 2006 i-VTEC runs in 6 cylinder or 3 cylinder modes.
I think the 2009 with i-VTEC runs in 6, 4, or 3 cylinder modes.
This engine was available in the FWD model only.
However, the i-VTEC, in 2006, also had an "intake manifold tuning valve."
This valve switches position depending on the RPM of the engine -- creates a long runner manifold for low rpm and a short runner manifold for high rpm -- this takes advantage of the inertia behind a moving column of intake mixture to produce a "poor mans supercharger" effect.
I think the valve switches position at about 4200 rpm.
In 2006, the VTEC was "incremental" or "stepped" variable valve timing -- not continuously variable valve timing. This engine was available in the AWD model only. |
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| netman88 |
VCM messes with the cylinders (deactivation/activation).
Not sure it's a good thing but many automakers are doing that on SUVs in particular to save gas. to produce better gas mileage.
Acura hasn't done that on the MDX since those buyers can afford the gas prices since they are afterall paying for a luxury vehicle.
I always wondering if the bugs has been worked out on that feature yet also.
VCM on the Honda Pilot came around 2006 models and thereafter. 2WD have them and not 4WD.
I have a 2006 4WD Pilot and there's no VCM but VTEC. |
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| VettePilot |
It is important to keep in mind that Honda has used i-VTEC to mean different things on different vehicles.
Some Honda models have variable valve timing i-VTEC engines.
The 2006 2WD Honda Pilot with the i-VTEC engine DOES NOT have variable valve timing -- only VCM.
But, the 2006 2WD Pilot also has an "intake tuning valve", that I mentioned in an above post, and it has a similar effect as variable valve timing -- although not quite as good. |
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| A6Pilot |
Note:
The dual stage intake manifold has been a feature for the Pilot ever since it was first introduced, not just since 2006. |
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| jscampbe |
My understanding is variable intake and outtake (is that the right word?) instead of just variable intake.
VCM is separate I think based on the cylinder managment system although they are interlinked |
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| VettePilot |
quote:
Originally posted by A6Pilot
Note:
The dual stage intake manifold has been a feature for the Pilot ever since it was first introduced, not just since 2006.
The "intake tuning valve", as far as my research on the subject found, was only available on 2WD models with VCM -- it isn't available on VTEC engines in the 4WD Pilot -- unless that changed after 2006.
And, I don't think there were VCM engines used in the Pilot before 2006 because they were all 4WD.
Now, variable valve timing is a different subject. |
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| sjlee |
i-VTEC engines w/ VCM were introduced in the Pilot in 2006 on 2WD models only.
Starting with the 2009 model, all Pilots have the i-VTEC engine w/ VCM now. |
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| N_Jay |
| i-VTEC was also used a a moniker (remember, "brand names" need not have technical meanings that hold up to any scrutiny) on the 2nd gen CRV, and a few other cars of the same era (If I recall correctly) |
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| switch |
The true i-VTEC, such as that in the engine on the Accord 4 cylinder, is not only truly intelligent, it works much better than the older VTEC.
Read the WIKI article - it explains the differences. |
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| N_Jay |
quote:
Originally posted by switch
The true i-VTEC, .. . . ..
VTEC and iVTEC are Honda Trade Marks.
They are anything that Honda wants them to be.
When people start adding the word "true", they are trying to say they know more then really exists to be known. |
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| switch |
quote:
Originally posted by N_Jay
When people start adding the word "true", they are trying to say they know more then really exists to be known.
So what you are saying is that you know more than someone who knows more than really exists to be known? :p
I meant i-VTEC as it was originallly supposed to be, and that is a VTEC engine that can vary the valve timing/lift/duration/etc. at more than a single RPM. |
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| youbetcha |
The VCM engine should not have an i-VTEC label, it is misleading, at best. Honda is mismanaging its brand.
If Chrysler put a "HEMI" on an engine with non-hemispheircal cylinder banks, or if Ferrari had put the "Testarossa" name on a car with blue engine paint, people would have been up in arms. I have a neighbor with an "i-VTEC" Civic Si, it is painted on the side of the car. I can tell you he didn't buy it for fuel efficiency because he drives about 45 miles an hour just in his driveway. I'll ask him what he thinks about Honda using "i-VTEC" to mean "fuel efficient" now.
Of course, it wasn't uncommon to see Chevy put "sport" or "rally" on the side of some of it's small, unsporty cars. :) |
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| N_Jay |
quote:
Originally posted by switch
So what you are saying is that you know more than someone who knows more than really exists to be known? :p
Nope!
And I try to never put "true" infront of a word to try to add credibility to "my" perception.
quote:
Originally posted by switch
I meant i-VTEC as it was originallly supposed to be, and that is a VTEC engine that can vary the valve timing/lift/duration/etc. at more than a single RPM.
Then say "originally", or "as in the XXX model".
Companies are free to change the meaning of their trade names. When you start assigning fixed "true" meanings, you are just setting yourself or others up to misinterpret then later. |
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| N_Jay |
quote:
Originally posted by youbetcha
. . . . I'll ask him what he thinks about Honda using "i-VTEC" to mean "fuel efficient" now. . . .
You mean like they have on the 2002 CRV? |
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| VettePilot |
When I originally looked into the i-VTEC Pilot a couple of years ago, it took some reading in different areas to determine what i-VTEC meant.
I eventually came to the conclusion that i-VTEC meant nothing more than "intelligent" VTEC, unless you tied it to a particular model and year vehicle.
Then, depending on the model and year, it could mean variable valve timing or cylinder managment, etc.
I also discovered that, in one place, the 2006 Honda Pilot Service Manual states that i-VTEC has variable valve timing -- which is absolutely wrong.
After reading that entry, I actually decided to look at the rocker arms myself to find out on my 2WD 2006 Pilot.
The VCM, 2WD 2006 Pilot only has the hydraulic rocker arm engagement on three cylinders on the rear bank.
No one is going to put variable valve timing on 3 of the 6 cylinders -- it is for enabling/disabling three of the 6 cylinders.
But, Honda did put the "intake tuning valve" on the VCM engne that has a similar effect to variable valve timing on all 6 cylnders.
Honda blurred the meaning of i-VTEC. |
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| switch |
quote:
Originally posted by N_Jay
Nope!
And I try to never put "true" infront of a word to try to add credibility to "my" perception.
Then say "originally", or "as in the XXX model".
Companies are free to change the meaning of their trade names. When you start assigning fixed "true" meanings, you are just setting yourself or others up to misinterpret then later.
OK, I'll either remember that, or if I can't, I'll stuff some alum powder up my butt so I can be anal enough to meet your standards. |
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| whizmo |
Honda has diluted the VTEC and i-VTEC labels by applying them willy-nilly to all sorts of engine technologies on various cars (and motorcycles) involving variable valve timing and/or actuation of different cam profiles. To my mind, they're no rhyme/reason to it. They're marketing terms and don't really have a technical basis at this point.
- Mark |
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| N_Jay |
quote:
Originally posted by switch
OK, I'll either remember that, or if I can't, I'll stuff some alum powder up my butt so I can be anal enough to meet your standards.
Either that or you can argue semantics of undefinable terms rather than having a clear discussion on the real topic.
As a very wise man says often "I would rather have clarity then agreement".:4: |
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| N_Jay |
quote:
Originally posted by VettePilot
. . . .Honda blurred the meaning of i-VTEC.
quote:
Originally posted by whizmo
Honda has diluted the VTEC and i-VTEC labels by applying them willy-nilly to all sorts of engine technologies on various cars (and motorcycles) involving variable valve timing and/or actuation of different cam profiles. To my mind, they're no rhyme/reason to it. They're marketing terms and don't really have a technical basis at this point.
As is their right! |
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| youbetcha |
quote:
Originally posted by N_Jay
Companies are free to change the meaning of their trade names. When you start assigning fixed "true" meanings, you are just setting yourself or others up to misinterpret then later.
But the acronyms do have meanings.
"VTEC" = variable valve timing and emissions control.
"i-VTEC" on the 6 cylinder does not have variable valve timing and emissions control. It is a single cam profile design.
Let me try this on:
"VCM" = variable cylinder management.
If next year they put "i-VCM" on an engine you would be OK if this meant it didn't have variable cylinder management, but instead was a 4 cylinder engine? |
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| youbetcha |
| What if "i-VTM-4" next year meant 2WD but instead had a full size spare? |
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| youbetcha |
quote:
Originally posted by N_Jay
http://www.honda.com/vtec/
http://world.honda.com/automobile-technology/VTEC/
So if all VTEC stands for is; Variable Valve Timing and Lift Electronic Control" and the "i" is just "intelligent",
How do you say they are right or wrong in its use?
Look at the second link for example. Item #3, the difference between a "normal" mechanism and the "VTEC" mechanism. The "i-VTEC" engine does not have the second "VTEC" cams as shown. The Honda V6 "i-VTEC" has one cam profile, like the "normal" mechanism shown.
The "intelligent variable valve timing and lift electronic control" Honda V6 engine does not have "variable valve timing and lift electronic control" it is a "non-variable valve timing or lift control" engine, in that respect no different from any other non-VTEC engine on the planet. It does other things but not variable valve timing.
Therefore, I think it is misleading to stamp "VTEC" on the engine block (with or without the "i"). |
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| N_Jay |
quote:
Originally posted by youbetcha
Therefore, I think it is misleading to stamp "VTEC" on the engine block (with or without the "i").
Yes, just as misleading as;
"better tasting", "New and Improved", and "Unsurpassed";
as well as;
"Coppertop", "Pentium", and "Hydromatic"! |
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| techgirl |
| You forgot one of my favorites - "Award winning ....". Especially hollow when the award won isn't mentioned. |
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| N_Jay |
Just a month ago, I had this exact same discussion about a manufacturers trademarked name for a couple of their systems and technologies in the industry I work in.
People were trying to apply strict technical distinctions to different uses and versions of the trademarked name.
It took just about as many posts to get the point across. |
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| switch |
quote:
Originally posted by N_Jay
Yes, just as misleading as;
"better tasting", "New and Improved", and "Unsurpassed";
as well as;
"Coppertop", "Pentium", and "Hydromatic"!
You forgot one of my personal favourites, although not trademarked as far as I know, and that is "organic". |
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| youbetcha |
| Hey, at least we can all agree on one thing that is clear. The ashtray is, in fact, not an ashtray, and I knew that as fact 100% when I bought the car. |
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| deparson |
Actually, as it relates to food products sold in the US the use of the word Organic is very tightly regulated.
Here is a quote from:
http://www.faqs.org/nutrition/Ome-P...anic-Foods.html
According to regulations set forth by the United States Department of Agriculture (USDA), organic foods must come from farms or ranches certified by a state or private agency that has been accredited by the USDA. Foods labeled "100 percent organic" must contain only organically produced ingredients, excluding water and salt. Foods labeled "organic" must contain, by weight, at least 95 percent organically produced ingredients. Products meeting these requirements must display these terms on their principal display panel and may use the USDA seal and the seal or mark of certifying agents on packages and in advertisements. Foods labeled "made with organic ingredients" must contain, by weight, at least 70 percent organic ingredients. Up to three separate organic ingredients may be listed on the principal display label, and a certifying agent's seal or mark may be used on the package. The use of a USDA seal is prohibited, however. Livestock can be certified "organic" if they have been raised on organic foodstuffs for over one year.
Other labeling provisions include:
* Packaging of any product labeled "organic" must state the actual percentage of organic ingredients and use the word "organic" to modify each organically produced ingredient.
* The name and address of the certifying agent must be displayed on the label's information panel.
* There are no restrictions on the use of truthful labeling claims, such as "pesticide free," "no drugs or growth hormones used," or "sustainably harvested."
* Products made with less than 50 percent organic ingredients may make no claim other than designating specific organic ingredients with the ingredient information.
quote:
Originally posted by switch
You forgot one of my personal favourites, although not trademarked as far as I know, and that is "organic".
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| youbetcha |
| Danger Will Robinson!! -- Danger Will Robinson!! Possible Thread Hijack Alert |
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| AWD+AWD |
Here's another example of how terms can be blurred when marketing steps in - Synthetic Oil. Originally synthetic was a technical term that companies used to describe oil that was engineered or manufactured. Now its a marketing term that can imply the oil has a synthetic base or group IV oil or it is a highly refined natural oil, group III, that provides characteristics of synthetic oil. Mobil sued Castrol over this point and lost.
This isn't a hijack to start an oil discussion, just an example of how an acronym like VTEC and i-VTEC can be changed to suit whatever situation needs to be addressed to differentiate one product from another. |
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| iivtecracerii |
VTEC just stands for Variable-valve Timing and lift with Electronic Control.
i-VTEC VCM is still VTEC in the raw meaning of the term/phrase. it changes the valve timing and lift on the rear cylinders to activate and deactivate them. when the cylinders are shut off, the valves are all shut...therefore going from whatever lift and duration (timing) they had to continuous no lift. and when something changes, you can say that it 'varies'. of course all of this is controlled electronically by the ECU. and there you have it, theres your VTEC...aka variable-valve timing and lift with electronic control.
the "i" just means the VTEC system (whatever version of it) is intelligent; meaning that it can be utilized at varying RPMs and load conditions. plain old VTEC had hard set RPM points to switch between cam profiles.
the i-VTEC on the K-series 4 cylinders mean "traditional" VTEC along with "intelligent" continuously variable timing adjustment which can advance or retard the entire camshaft in relation to the crankshaft.
they arent using the term loosely at all. the acronym VTEC does not stand for 'low rpm economy and high rpm power cam profiles with an upper-mid rpm switchover point,' even though that is how it began. VTEC is still VTEC, whether its "traditional" VTEC, i-VTEC, i-VTEC VCM or whatever version they may come up with in the future. it might be used to boost performance or economy, it might work on all or only some cylinders, it might be "intelligent" or not, but at the end of the day they all do the same basic thing: change valve timing and lift. |
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