And that has WHAT to do with your statement about variable valve timing to which I was replying?
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It has nothing to do with variable valve timing and everything to do with your statement that reducing fuel consumption also reduces emissions. The EPA is concerned about pollutants. CO, NOx, unburned hydrocarbons, smoke etc.
The only thing that can’t be avoided in an engine that burns more fuel is carbon dioxide and H2O and the EPA doesn’t regard these as pollutants.
Are you denying that fuel sippers can be dirty?
I think it was a matter of making a nationally-aspirated engine that was the best of both worlds in terms of fuel economy at cruising speeds and maximizing power when you mash the throttle.
Have you driven a car with variable valve timing? It’s a hoot.
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It also happens to be true that many auto consumers want good fuel economy. They vote that way in elections and with their dollars. Just look how popular the Prius is.
I think I own one. VVTi stands for variable valve timing + intelligence, that is the switchover point varies with throttle opening instead of being strictly an rpm thing. When the throttle is nearly closed, it switches over at a very low rpm and is in the “high rpm” mode while idling.
You cannot compare two totally different vehicles with dramatically different engines like a 2018 SUV and a 1968 Yamaha 60 two-stroke and claim to have made a point. That’s so inane as to be unworthy of response. I would have thought you capable of better, but I guess I’d have been wrong.
C’mon, get real. I’m sorry, but that level of pathetic ridiculousness I won’t even try to construct a response to. If you want to claim that there’s no relationship between VVTi improving gas mileage and reducing emissions too, you go right ahead. Have a ball.
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Yes, I can compare two totally different vehicles with dramatically different engines to refute a ridiculous blanket statement such as:
I’m afraid he’s got you@MB. A 1993 geo metro gets better fuel economy than a 2005 Honda Civic, but the ULEV Civic will have better emissions. So will a 1998 LEV Civic.
The “lag” the commentor was referring to could well be a glitchy rheostat. Like any electrical motor, it can develope a “dead spot”. I’ve had to change many at either the pedal or throttle due to surging or lagging or whatever you want to call it. But, I think you are correct, in a properly function system there would be no lag because of the drive by wire system.
Variable valve timing has always been intended to optimize breathing over the entire rev range of the engine.
Back in the 90s, Camrys and Maximas had 3L V6s that made around 190hp. Those engines had fixed valve timing that compromises idle speed and high speed breathing. They weren’t meant to rev far beyond 6000 rpm as increasing engine speed would not take in more air given the compromised valve timing.
Meanwhile, Honda’s 3L V6 in the same era would switch to a high speed valve setting, which would be unusable at low speed. But the high speed setting allows it to breath all the way up to 8000 rpm, producing 270hp doing so.
In 1995, the Accord V6 had 190 hp, by 1999 it was up to 200, and by 2005 it was 240 hp.
My Honda idled in normal or high-power mode, and used atkinson mode only for cruising.
That has been done… By BMW, in the early 2000’s Called Valvetronic, it varies the valve lift and is combined with their VANOS variable cam system to vary timing in addition to varying lift.
With a link to an Engineering Explained video
All of this stuff is done to expand the operational envelope of engines. Wider power band, better overall efficiency, lower fuel consumption and also lower emissions of bad gasses.
Since the EPA got CO2 defined as a pollutant (all you CO2 expelling people are polluters!) Fuel economy is a direct result of that since X gallons of gasoline produces Y lbs of CO2 no matter how fast the X gallons are used or what emission system is present.
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Jtsanders, That 270 horses v6 was installed in the nsx. I know that’s a long way from the Camry, but the point is what variable valve timing allowed Honda to build.
No we’re not, we expel ORGANIC CO2. It’s pure as the driven snow.
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Thank you. I am understanding that I just had to learn to operate throttle by wire and VVT. Years ago I figured out how to make it work but did not know why I should have to. The dealer said I wasn’t the only well experienced M/T driver having trouble with the new systems. I feel like a dinosaur watching the mammals out breed us.
I say the same thing about my methane emissions… but my wife does NOT accept that! 
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