Slow acceleration, is this normal?

[speedle1]

Ok so I have been looking at getting a new Juke since before they came out last year. I finally decided that now was the time to buy a new car and headed to the dealership to test drive one. I jumped in a top of the line silver AWD SL Juke and pulled out of the dealership. The car felt pretty peppy from a roll but was absolutely lethargic from a start. When I would first press on the gas pedal from a dead stop the car would hesitate and accelerate really slow. Then a couple seconds later it would start to accelerate rather well. Is this normal? The car was on Sport Mode and the AWD was turned off. I didn't have my foot all the way to the floor but I was pushing the gas pedal fairly hard. What gives, is this what the CVT transmission is like? Thanks for the responses. Other than that issue I really liked the car.

[we5leyz]

Put it in AWD and floor it. It also takes the computer a while to adjust to your driving personality.

[load97]

Unfortunately, the Jukes are like that. One of the things you just have to get use to if you own one. Part of the problem is probably just the turbo taking time to spool up.

[we5leyz]

You can always brake torque til 3,000rpm then take off

[tortoisegirl]

I don't have mine yet but on the test drive the acceleration rate seemed surprisingly similar to my Scion xA. For my car it does better to slowly step on the gas than to push it and then wait for the power. Hubby doesn't seem to get it as his Civic is very responsive apparently (I've never drove it as its a manual...scratch that...I tried to drive it once lol but gave up). I'm probably in the minority in that I don't care about power. I chose the Juke based on everything else, and hubby wanted the power (and also didn't seem to mind the response time as long as it had the power, although it might get to him when trying to pass).

[curious]

Lethargic "off the start" sluggishness...

Its definetly not turbo lag and has nothing to do with the ECU learning your driving habits...We've have many discussions about this on the forum and reviews published on this topic...Unfortunately its symptomatic of Nissan's CVT itself...And its also fairly well known that Nissan is currently having some problems with their CVT's intermittently exhibiting extemely sluggish "off the start" acceleration...

Just google "Nissan CVT problems / issues" and see how widepread this "sluggish" CVT problem is...you'll also see this topic also discussed on many other Nissan forum sites...

CVT Performance Problem

As far as "turbo lag" is concerned...Understand that the turbo on the Juke doesn't even begin to start spooling up into an "initial boost" condition until ~2800rpm... Now turbo lag is the actual "delay of initiation" of the "spooling up of the turbo" at that programmed launch rpm level and that the boost threshold of a turbo system describes the lower bound of the region within which the compressor just begins to operate....Below the boost threshold level(meaning from a stopped position until ~2800rpm) the compressor will not even produce initial boost and therefore turbo lag doesn't even come into play during this period...

If you really want to feel what good "off the start" acceleration should feel like then I suggest taking an MT out for a test drive and compare it to a CVT....you'll definetly feel the difference and see for yourself that the Juke really doesn't have much turbo lag at all to it...It would have been really great if Nissan had introduced an MT AWD Juke...IMO a big miss on Nissan's part and many reviews I've read have mentioned this as well...Maybe a 2013 MT AWD Juke in the future?

[Mo Noyz]

Below the boost threshold level(meaning from a stopped position until ~2800rpm) the compressor will not even produce initial boost and therefore turbo lag doesn't even come into play during this period...

Isn't this the definition of turbo lag? The lag is the time between idle and when the turbo starts spooling. Right?

[curious]

Isn't this the definition of turbo lag? The lag is the time between idle and when the turbo starts spooling. Right?

Sorry no...its the lag time starting from the "point of boost threshold" (~2800rpm) to when the boost actually begins spooling...the turbo is not even supposed to be engaged during the time period from idle to boost threshold...The lag time from idle (stopped) to initiation of pre-boost would be more about "throttle responsiveness" not turbo lag...

Look at it another way... while your are driving under a slight boost condition punch down on the accelerator... Turbo lag is the time required to change speed, reinitiate boost, and function effectively in response to a throttle change...if we really had profound turbo lag the hesitation during that time period would be obvious!

Hope that was helpful...

Anyways...back on topic...the pronounced "off the start" lethargic sluggishness folks are complaining about has more to do with the CVT...And I'm glad to see Nissan is working on it to fix the problem quickly

[Jersey Devil]

I don't know why you are asserting this, but turbo lag isn't exclusive of negative pressures.

Turbo lag is simply the time it takes for the turbo to reach it's limited pressure state. THere is no clause saying it has to be in postive pressure state.

Example, you are cruising at 70 mph, you are under light throttle. The manifold will be in a partial vaccum at this state, generally around -400 to -600 mbar. You immediately go from this part throttle position to WOT. Since you were in a negative pressure state the turbo needs to spool up to it's regulated pressure state. THere is no stipulation to the definition of turbo lag stating that the turbo must be in a positive pressure state before opening the throttle further.

Turbo lag definition: Turbo lag is the time required for the turbo to change speed and function effectively in response to a throttle change.

THe entire function of twin scroll and VVT turbos (variable vain/geometry turbine) is to reduce turbo lag. What they are reducing is spool time from a negative pressure state.

Throttle response is the responsiveness of the vehicle to throttle (accelerator pedal) modulation. When the accelerator pedal pressed suddenly, how fast power output of engine increases implies the throttle response of that vehicle.

[curious]

I don't know why you are asserting this, but turbo lag isn't exclusive of negative pressures.

Turbo lag is simply the time it takes for the turbo to reach it's limited pressure state. THere is no clause saying it has to be in postive pressure state.

Example, you are cruising at 70 mph, you are under light throttle. The manifold will be in a partial vaccum at this state, generally around -400 to -600 mbar. You immediately go from this part throttle position to WOT. Since you were in a negative pressure state the turbo needs to spool up to it's regulated pressure state. THere is no stipulation to the definition of turbo lag stating that the turbo must be in a positive pressure state before opening the throttle further.

Turbo lag definition: Turbo lag is the time required for the turbo to change speed and function effectively in response to a throttle change.

THe entire function of twin scroll and VVT turbos (variable vain/geometry turbine) is to reduce turbo lag. What they are reducing is spool time from a negative pressure state.

Throttle response is the responsiveness of the vehicle to throttle (accelerator pedal) modulation. When the accelerator pedal pressed suddenly, how fast power output of engine increases implies the throttle response of that vehicle.

Yep..agreed....good points ....just different ways of saying the same thing.....we have similar definitions of turbo lag and throttle responsiveness...and if there is indeed turbo lag it tends to be much more pronounced under a limited pressure state...

Now back on point... the apparent "lethargic" off the start sluggishness is not due to turbo lag...