Armada-Variable Valve Timing-Mileage VS QX56

[q56er]

Looking at the official Nissan Armada web site I see the 5.6l V8 has CVTCS. Looking at Infiniti's site, the QX56 does not list this in the specs for it's 5.6l V8. It also lists the Armada V8 as being a flex fuel motor. It appears the Armada has a more efficient engine although the EPA mileage numbers are identical. All that additional technology for what I ask? Anyone care to confirm there is no variable valve timing on the QX?

[Timmbo]

I thought the QX56 DID have VVT.

[q56er]

Nothing I've read on Nissan's site hints at VVT on the QX56 engine. The Armada section on Nissan's site however lists it quite clearly. Has anyone else seen VVT advertised on the QX?

[q56er]

According to Wikipedia the QX56 uses the VK engine that does have variable valve timing on the intake valves. Both Nissan's descriptions for the Titan and Armada mention VVT and the VK56DE engine. From this information it appears the QX56 does have VVT even though it's not specifically mentioned on the official web pages for the vehicle. My interest in the subject lies in the fact that VVT technology can not only improve an engine's fuel economy but emission ratings as well. Toyota for example has introduced VVT on both the intake and exhaust for the 2008 5.7l V8 used in their Tundra and Sequoia which could be in part responsible for it's ULEV-II emissions rating. Titan, Armada and the QX56 all carry LEV emission ratings which is several levels down on the greenness scale. Kuddos to Toyota for raising the bar on emissions. The page listed below has some good info on emissions.http://www.arb.ca.gov/msprog/LEVPROG/appndx-e.pdf

[q56er]

Instead of relying on the internet I actually went out, opened the hood and started looking for proof of VVT. I found at least two electrical connections on the front of the valve cover connected to what looks exactly like variable valve timing. I'm almost certain the QX has VVT now. There is also a sticker in the engine compartment that is a LEV2-LEV certification. That means our QX56's are much more clean burning than the original LEV cert.

[Timmbo]

Instead of relying on the internet I actually went out, opened the hood and started looking for proof of VVT. I found at least two electrical connections on the front of the valve cover connected to what looks exactly like variable valve timing. I'm almost certain the QX has VVT now. There is also a sticker in the engine compartment that is a LEV2-LEV certification. That means our QX56's are much more clean burning than the original LEV cert.

That's awesome, now those of us with the 5.6 beast can call ourselves "tree huggers." I alway get a kick out of people that tell me I shouldn't waste so much fuel by driving such a big rig, an usually it is coming from someone driving a Trailblazer or an Explorer, and I would be willing to bet that I get the same (maybe better) gas mileage as they do. At least I can run Ethanol in mine if I so choose, you can at least grow my fuel. LOL!

[q56er]

While we’re on the subject of environmental concerns I’ve noticed there are quite a few new Flex Fuel cars/trucks coming out. In short you can burn up to 85% ethanol in these vehicles. Well, that sounds great, alcohol burns cleaner and puts far less carbon into the atmosphere. Or is it? From what I’m reading, producing the alcohol for automobiles creates a much larger carbon footprint than processing crude oil to put in our tanks. Now it’s more complicated than that but the general consensus is that replacing food crops with corn to make fuel for our cars is maybe not the cure-all the government would have us believe. To make matters worse the energy density of ethanol is quite a bit less than that of gasoline. That means if you fill up with gas and can drive 400 miles filling up with an 85% blend of alcohol/gas might only get you 300 miles. I haven’t seen very many stations that carry this new blend but I’ll bet this stuff is just as or more expensive than regular old gasoline. Up next: The Electric Car. Just plug it in at night the next day drive all over town secure in the thought you aren’t destroying the planet. Can you imagine if a ½ a million people in LA plugged in their cars tonight? Their entire power grid would melt down. But I’ll leave that for another thread.

[Timmbo]

While we’re on the subject of environmental concerns I’ve noticed there are quite a few new Flex Fuel cars/trucks coming out. In short you can burn up to 85% ethanol in these vehicles. Well, that sounds great, alcohol burns cleaner and puts far less carbon into the atmosphere. Or is it? From what I’m reading, producing the alcohol for automobiles creates a much larger carbon footprint than processing crude oil to put in our tanks. Now it’s more complicated than that but the general consensus is that replacing food crops with corn to make fuel for our cars is maybe not the cure-all the government would have us believe. To make matters worse the energy density of ethanol is quite a bit less than that of gasoline. That means if you fill up with gas and can drive 400 miles filling up with an 85% blend of alcohol/gas might only get you 300 miles. I haven’t seen very many stations that carry this new blend but I’ll bet this stuff is just as or more expensive than regular old gasoline. Up next: The Electric Car. Just plug it in at night the next day drive all over town secure in the thought you aren’t destroying the planet. Can you imagine if a ½ a million people in LA plugged in their cars tonight? Their entire power grid would melt down. But I’ll leave that for another thread.

Dude, I love your post! All so very true, actually, when you purchase a flex fuel vehicle, they most the MPG in regular fuel, and if you were to use E85, so you can see on any vehicle what the mileage would be. I like your touch on the electric car subject, but you didn't mention one other drawback to electricity........we all take for granted that we can plug something into the wall and it works, we all forget that electricity has to be produced, it isn't just there magically, except for lightening. Like I said, you post is great, and the coming years will be interesting in terms of energy and where we get it from.

[q56er]

I feel bad, running on about alternate fuel sources without offering up some realistic alternatives. I mean it’s ok to whine and complain but without alternatives to the problem it’s just whining and complaining which isn’t helping anyone!First off, electric drive for cars is phenomenal. Electric motors develop peak torque at zero RPM. You have to wind up a gas engine to at least 2000 RPM to find the torque. Electric cars have already proven themselves on the dragstrip as formidable opponents to gas powered vehicles. The other obvious advantage is power to the motors can be delivered by a couple wires. Transmissions, drive shafts and all the power robbing gears, bearings and other mechanical components are obsolete. There’s even a company working on developing high output motors that integrate directly into each wheel of the vehicle so you won’t even need CV joints or half shafts. Hybrids like the Prius are great for delivering higher MPG around town but don’t improve on highway mileage to any great extent. Hybrids still use transmissions, in most cases they’re infinitely variable, which is cool but they’re still robbing you of power. A closer look into the Prius reveals that the computer is constantly topping off the battery at the expense of running the gas engine. Why don’t they run longer on battery power? The reason is most likely to extend the life of the battery. By only using 10% of the battery’s total capacity Toyota is able to warrantee these lithium ion batteries to something like 8 years, 100,000 miles. Tradeoffs! Something else about the hybrids that could possibly be improved is the way in which the combustion engine is used. Gas engines generally run most efficiently at the top of the torque curve. For gas engines that peak-torque occurs at higher RPMs than for diesel engines. If the whine of a gas engine running at it’s peak efficiency offends people then use diesel. Diesels develop their torque at much lower RPMs. Diesels are also more fuel efficient. There’s more energy in a gallon of diesel than in a gallon of gasoline. Check out the new diesels, they far cleaner burning and quieter than they used to be. Running at peak efficiency is just half of the solution though. The real gains, I believe, will be in using the combustion engine solely for the purpose of charging the battery. Spin up the gas or diesel, charge the battery and then shut it down. Power to the wheels, whether it be two or all wheel drive, would be from the electric motors, preferably integrated into the wheels themselves. In this scenario a larger battery would be required but you could get away with a combustion engine half the size currently used and the conventional drive train like transmission, differential, transfer case and drive-lines would be a thing of the past offsetting the added weight of the battery. Would I buy a QX56 with electric motors on all four corners and a small diesel engine to charge a 500lb battery? You bet. Better weight distribution, more low end torque, whisper quiet, and best of all, mileage would be 30/40 MPG instead of 12/17 MPG.

[Black stallion]

One other drawback of the hybrids is when you do have to replace that battery, it will probably cost you more than the car is worth (8-10K).

I rode in a hybrid bus at a trans conf. and it was very interesting technology, but not at all efficient enough to justify the cost. Only traveled about 25 miles before needing to charge. I imagine with the tech we have today, the automobile will transform by leaps and bounds in a very short time. Just think, the car really isn't that old.

Now, some thought food.. Why is it no one has been able to produce a car that could top the 53 mpg Geo metro from 16 years ago? If I could find one that wasn't all banged up I would give the hybrids a run for their money.

[q56er]

Cambridge University in Britain is working with nano technology to develop a super capacitor that can supposedly store far more energy/unit volume than what is current possible with batteries or capacitors. Capacitors historically are only used for very short bursts of energy but if this claim is true we could see a giant step forward in storing electrical energy. They admit that bringing this technology to hybrid vehicles is still 6 to 8 years out but say they may be much closer to bringing this to market in smaller applications such as ICs and things like laptop batteries. The fact that so much work in the area of electrical storage is being done around the world is good news for us. Laptops alone have driven storage technology thus bring prices lower. Now that Hybrids are gaining traction with consumers the pace will no doubt continue to increase.