The truth about Versa, CVT and Milage

[chano129]

Sorry Jem,had to run for a while, back to what i was say, the nissan and renault engineers knew that driving in traffic consumes alot of petrol,so what they did was to find a way to maximize fuel effeciency.example,;take an AT/transmission couple to the older 1.8 found in the Sentra, now you give it a constant acceleration the rpm will goes around three to four, then shift, does it again then shift until it settles to about 2.5 x1000 rpm.Now unlike the the previous 1800cc this new engine with an AT/transmission will shift at 2400 rpm or suppose to do so, and remember the computer will send in less gas.

Now my source of information was taking for nissan global and from other websites in the past, I went to look for them so you could read it and understand more, but all i can find now is this

http://www.nissan-global.com/E....htmlh ... /E....html

Hope this help you understand the whole theory concept and as I said in one of my post Nissan is back,and not only that, they have new advance technology to challenge their rivals.

[chano129]

This thread will explain more in details the operation of the specific CVT in the Versa.The CVT in the Versa has a lower and higher gear ratio. It has wider gear ratio than the four speed AT/transmission found in the versa , it gear ratio is more like an 5 speed AT/ transmission.However, as we know the CVT has ability to vary in a range of infinite ratios. the range is about 2.4 to .4. The CVT has ability to read load and address it self to the best gear ratio, to accomodate the specific load at that specific time. The 1800cc as we already know when accelerated nearly achieved maximum torque at 2400 rpm, the CVT will quickly runs to its higest gear ratio,because that is what it was design and programme to do,while the speed increases.That is why it is recommended to drive the car at 2500rpm.However with an higher rpm the CVT might not reach it highest gear ratio, although it will be at a lower gear ratio,but still closer to the highest, the CVT will rotate it self to the best possible gear ratio to perform the task it ask to do.This also happen when passing.When desending a hill the CVT will feel the load, and rotate itself to the best possible gear ratio to keep things under control, that is why people experience a drop in speed.The dis advantage I see with this transmission is that when driving you do not know at which gear ratio it is at.

CVTs can have a manual selection but the versa CVT did not come with that option.

Over all the CVT is a better transmission than a AT/transmission.I agree with Jemdawg about the manual and the CVT.I would like to have control of my gear ratios instead of the CVT control them.then i can be sure i am driving at a higher gear ratio.

[Gosh]

So this engine/transmission works best at 2400rpm,for gas consumption ?I do pretty much 100% city driving, besides going from a dead stop my car rarely breaks 2k rpm. traffic and lights make it very hard to keep car at such a high rpm without having to break within a few metres. normal speeds for me are 60-80 kms/h, rpms are almost always at 1700ish. so would i get better gas consumption driving faster and harder on the gas pedal ?

I do not know very much about this cvt, so forgive me if i am right out to lunch on this post.

[LA02MAX]

Now mister moderator sir, with acknowlegdement of you being here, i want to show you why , this guy(lomax) thread miss the whole idea,and partly mislead the forum to only think it is because driving at 2500 rpm you have good mpg,he is correct about the theory of less fuel enter the engine at 2500 rpm,, but that is not the main reason why it is important to drive the VERSA a that 2500rpm, the main reason is the engine was particle design to reach or achieve at least 90% of it torque and power at 2500 RPM, is was design for that purpose for fuel efficiency, and the torque converter is different from the older torque converter, and i think it called: a lock up torque converter.That is why the CVT can reach its maxium range, because of the gears of the CVT in the epicyclic.

I know you are saying that since the engine is at it's optimum performance range, it is better for gas at highway speeds, but my whole argument was that you said the CVT has gears, which was what you originally tried to explain to people. What you quoted in one of your posts above was absolutely correct. You said I was confusing people, but I just didn't want anyone to get in their head that the CVT had gears, because as you well know, they do not. I'm glad you cleared up any misconceptions and I'm sorry for bantering back and forth with you, but I just wanted to make the info. right, and now it is

So this engine/transmission works best at 2400rpm,for gas consumption ?I do pretty much 100% city driving, besides going from a dead stop my car rarely breaks 2k rpm. traffic and lights make it very hard to keep car at such a high rpm without having to break within a few metres. normal speeds for me are 60-80 kms/h, rpms are almost always at 1700ish. so would i get better gas consumption driving faster and harder on the gas pedal ?

I do not know very much about this cvt, so forgive me if i am right out to lunch on this post.

Well, what he's saying is that the engine is very close to it's optimal power at 2400 RPMs (like he said 90% of the torque available). This is a good thing for gas mileage, because it takes less aggressive throttle inputs to keep the car moving (fighting the outside forces trying to slow it down such as wind resistance and friction) on the highway. That's why many of the V6 and V8 cars are at very low RPMs at high speeds, because they have plenty of power to keep it moving, even at a low RPM. For city driving, again, accelerating at 2400 RPMs will get you to speed in a very efficient manner, because it gets you there quickly, but it doesn't use too much fuel. Once you get to speed (say 40 in town) it's better if your car is at a lower RPM, so 1700ish is good for city driving. If it were at a steady 2400 in town, it would actually be worse, because you do not need as much power to keep you moving as you would going 70+

[BenDupre]

Drive your car like normal. If you don't break 2000 RPMs then you're using even less gas then if you did. Accelerating quickly and then braking is a waste of energy. You are most efficient accelerating slowly and coasting to the stop sign.

Ben

[motoguy128]

chano, I think you forgetting that an engine performans differently at partial throttle that at full throttle. Most ECU's run a richer mixture at larger throttle openings and higher RPM's to provide extra torque at the cost of fuel economy and emissions.

At partial throttle, the engine displaces the same volume at a given RPM, but the intake charge is less dense. I beleive that the low peak torque at low RPM's may be a liability for having good effeciency at part throttle and low RPM's where the engine spends the most time in the real world. A flat torque curve is good for driveability and performance, but not nessesarily for economy.

Yes, I do know that peak torque is achieved at part throttle at lower RPM's. WHen I say "part throttle" I refer to throttle positions less that that required for maximum output.

What I would like to know is what the difference is between other enignes in the 1800cc class. The best performers for economy are the Toyota Corolla drivetrain and the newest Honda Civic Drivetrain. These are also the 2 best selling compact cars in the US. (THe Civic is overpriced and too small, and the Corolla doesn't have good ergos, to little legroom and badley needs an update)

[LA02MAX]

chano, I think you forgetting that an engine performans differently at partial throttle that at full throttle. Most ECU's run a richer mixture at larger throttle openings and higher RPM's to provide extra torque at the cost of fuel economy and emissions.

At partial throttle, the engine displaces the same volume at a given RPM, but the intake charge is less dense. I beleive that the low peak torque at low RPM's may be a liability for having good effeciency at part throttle and low RPM's where the engine spends the most time in the real world. A flat torque curve is good for driveability and performance, but not nessesarily for economy.

Yes, I do know that peak torque is achieved at part throttle at lower RPM's. WHen I say "part throttle" I refer to throttle positions less that that required for maximum output.

What I would like to know is what the difference is between other enignes in the 1800cc class. The best performers for economy are the Toyota Corolla drivetrain and the newest Honda Civic Drivetrain. These are also the 2 best selling compact cars in the US. (THe Civic is overpriced and too small, and the Corolla doesn't have good ergos, to little legroom and badley needs an update)

golf clap Not everything related to fuel economy has to do with throttle position. IMO the CVT in the versa keeps it at a very good engine speed throught the speed range, and with a few more years, I'm sure nissan is going to catch up to toyota and honda in the fuel economy area. I think the main reasons the civic gets such good gas mileage (40 mpg for an auto is really nice) is because it's lighter than the versa (not by much, surprisingly), it has much better aerodynamics, 5 gears (pretty comparable to the CVT at highway speeds) and because honda has been perfecting the 4-cylinder gas sipper for a couple decades now and they're technology shows. Nissan is doing damn good with the versa, and I think that once we start seeing more cars offering the CVT, it will only get better.

[chano129]

I dnot want to drift but since You guys have no idea what is going on let me inform you.

1.MR LMAX you are very much correct,and I think nissan is already there,just that people does not see it, because the versa is a bit too heavy, because nissan choose to make people comfortable, for the expense of a little amount of fuel.People are forgetting that the engine is mated to a CVT transmission, and not all depends on throttle.2.Most 1800 achieve their maxium torque at higer rpm.If a car get it maximum torque at less rpm, I know for sure you have a stronger power stroke, if i have a stronger power stroke, with less rpm and less fuel entering my chamber would not that been fuel efficiency?3.Motoguy you told me the versa average 32mpg,I think that is very excellent , what more could you want from a car which is heavier than a corolla and civic. I bet if you put 300lb in the corolla i bet you any money it is going to burn more.4.I must corect you LMAAX nissan has already overtaken honda and toyota in technology,I read about the Honda technology that is going to be in the next honda civic engine about 2008,and it is similarto nissans, but i must inform you that it was nissan who first came up with that idea and it is called the VARIABLE VALVE EVENT AND LIFT SYSTEM.Nissan is also going to introduce a new technology called the VARIABLE COMPESSION RATIO PISTON CRANK SYSTEM.Nissan already has also a hybrid(STARTED YEAR 2000) car they made by their own called the Tino hybrid, but found it expensive, that is why it never produce a lot. But if you notice the hybrid Altima nissan it consists of nissan very own Battery and motor, but uses toyota converter.Nissan is studying to come up with a better in house, which is cheaper and realiable, than this one toyota has, and they are going very fast about it.There are more but hey I already say alot.OOh! I need proof so here they are.http://www.nissan-global.com/E....htmlh ... /E....html

5 Motoguy it is good that you mention that toyota and honda is doing good in US,but if you go to Japan and some where else you would find it in the reverse, it would be nissan and honda.The nissan Tiida (Versa) was choosen by the Hong Kong Police,over its rivals because one good point it has a better fuel effiency.

As i said before nissan went through hell with that bankrupt thing, but they had little brother renault pushing in some cash got them out of them troubles and now they are back kicking ***.

[chano129]

Very good MR MAX you have got the idea, let me expand a bit more, if i drive in traffic at 1700 rpm i could achieve about 50% OF MY TORQUE FROM THE VERSA,and as mr Max said less fuel, unlike the other engine it could be around 20% to 30%.Now do you see where the fuel efficiency comes in?

N.B. I read over nissans script yesterday and they said it was from it was in the range of 2000 rpm to 2400rpm and not exactly 2400 rpm.

[chano129]

AND PLEASE PEOPLE THE FORUM HAS NEW THREAD CALLED EV'S REVISED GAS MILAGE, DO SHARE YOU INFO OR GIVE SOME INPUT.

AND FOR THOSE WHO STILL THINK COROLLA IS WAY AHEAD WITH A 38 MPG,XTERRAVERSA IN EV THREAD HE IS AVERAGING ABOUT 37 MPG AT 5500ISH MILES.i HAVE READ PERSONALLY THAT A GUY GOT 40 MPG ON HIGHWAY BUT HE HAS MORE THAN 5000 MILES.NOW IT IS PROVEN TO BE TRUE THE VERSA ENGINE DOES NEED TO BREAK IN TO REFLECT GOOD MILAGE.

[chano129]

motoguy info you ask for :

VERSA 122 hp@ 5200 rpm 127 lbft torque @ 4800 rpm

Civic 140@6300 rpm 128 @4300

Corolla 126@6000 rpm 122@4200

[LA02MAX]

hmm...i was not aware that nissan was the first to release VVT. I always thought it was toyota, but kudos! I love the VVT on my maxima even though it's only on the intake cams (new 350z, G35, Altima, etc. have both intake and exhaust VTC). It is definitely noticable when compared to a hybrid VQ35 with no VVT.

Although nissan may have the technology that toyota and honda have, they still have quite a while to go reputation-wise, sadly. Most people think of reliable and fuel efficient cars being japanese, but the first that comes to mind is usually toyota, then honda, then nissan. These past few years nissan has had a horrible track record for reliability (the VQ35, which is still a great engine and used in most all of the nissan line-up has oil consumption issues, as does the QR25 which is in the best selling nissan; the 4-cyl altima)

If you remember, toyota was in a similar position around 15 years ago, so I predict that pretty soon nissan will catch up and get their act together. One can only hope

[chano129]

Actually Variable vavle timing started early as in the 80s and it was either the honda or nissan applied it not too sure, but toyota last did it recently when they carried the VVT-I.The Honda is known as vtech and was recently design better and called I- vtech there is going to be a different one in 2008 called advanced I-vtech.The nissan type was calle V-SPEC and on the sentra engines with GA1600cc DE it was called VTC and recently like honda design a better one called CVTC,just like honda, nissan is going to have a new one and it is called VEL.

NB Imade a mistake in my early post about Honda bring it new technology in the civic, actually i do not know but as honda says it will comes in 2008.

ACTUAL WE HAVE DRIFT TOO MUCH ALREADY COULD WE GET BACK TO VERSA ?

[chano129]

I expand my view alittle , i do not know of anything wrong with the VQ3.5 V6 but i do know they have a realiability issue with the QR 2.5. They have updated the engine and hope fully it would be better.And for toyota I think they are still living 15 years back, for a car company that has never being bankrupt like nissan and honda who almost went there, it should be more outstanding in designs, realiability and gives better interior than what they are giving, to me they have fail, but that is my opinion.

[chano129]

The versa only has the CVTC on the intake. I think that because they are going to applied the VEL in the feature on the smaller engine they are buy some time. One problem I have with nissan, they take too long to applied the technology they have in Japan to there Americian siblings.For example in Japan right now on their 3.5 315 hp skyline,they are the first car company in the world that has a four wheel drive active system,which adjusts the steering angles of the front and rear wheels in accordance with driving speed and steering operation,but yet not available on the G35 in the US.Now that is just dum!! Now to be fair, Mr. Goshen is tring to bring all the available technology global since.

NB check out the altima coupe

[Quotacious]

Versa's new 1.8 liter MR (MR18) engine (shared with Renault) produces and estimated 120 HP and 125lbs of torque while providing 36mpg on the highway when coupled with the Xtronic CVT (Continuously Variable Transmission). The contemporary engine is a 16 Valve, Dual Overhead Cam, all aluminum light weight block, and that's not all. Nissan has incorporated a continuously variable timing control system to further maximize fuel efficiency and power band at all RPM's.

[gottafly]

Here's a good article all about CVTs with some good moving graphics for us simple folks.

http://auto.howstuffworks.com/cvt.htm