Auto transmission question

[PaulRay]

I have a 09 versa HB with the reg auto transmission in it. I've noticed when I get on the interstate and the car isn't fully warmed up, that at 70 mph it'll read 3200 RPM. It almost sounds like it's stuck in the passing gear. Then after a few mins the RPM will kick down to 3000 RPM. Is this normal, makes me wonder why I'm only getting bout 28 mpg since I drive interstate all the time and the RPM is a lil higher?

[Promise Land]

My '09 does it also, but I'm "interested" in the reason why also. Mine will be at 3100 at 70 and will lower down to 2800 after a minute when it settles in. It's like a overdrive to the overdrive gear. I am usually around 32mpg, but I tend to drive 50% of the time at 60mph rather than 70.

[conversation]

I also have an 09 versa HB with the reg auto 4 sp trans. I'm pretty sure my tach is at 2800 at 70 mph, and stays there. at 60 mph I'm at 2400. It is higher rpm than the typical 4 cyl car, I think. I can get 35 mpg, if all highway, if I keep it between 60 and 65 mph, in summer.
Modified by conversation at 10:32 AM 2/16/2010

[CrankyVersa]

My cvt usually sits around 2000 or under a bit , no issues so far.

[V-Man]

It could be the transmission torque converter kicking in.

[shiryu0]

It could be the transmission torque converter kicking in.

that, and the car is trying to warm everythin up to operating temp.........

[Shad0wXCalibur]

It's just the lock up torque converter. It sorta acts like a 5th gear but it's not a gear. It locks the transmission to the engine like a manually driven car to stop the slipping at cruise thus reducing engine rpm, increasing gas mileage, and reducing wear on the transmission. It won't lock up until the car has reached a certain temp. The CVT automatics (they have it, too) lock up early which is why it has that rpm surge when you take it off then it suddenly drops.

[br4dysays]

yeah this def has to do with the operating temp.

if i head out onto highway speeds even right after the car 'blue light' goes out, it'll stay @ higher RPMs for a few minutes til everything is warmed up then it'll go down to its usual.

i avg about 29mpg roughly, but do a mix of driving.

[sfd6532]

My truck stays in drive until it is warm and then shifts into overdrive at normal temp. It sounds like this does too.

[08versailles]

It's just the lock up torque converter. The CVT automatics (they have it, too) .

I did not know the CVTs also have a lock up torque converter.
No wonder they can get better mpg highway.
How soon [from stand still on warm engine/transmission] does it lock up?
Sorry 'bout the nerdy techie question

[CoupeVQ35CVT]

It's just the lock up torque converter. The CVT automatics (they have it, too) .

I did not know the CVTs also have a lock up torque converter.
No wonder they can get better mpg highway.
How soon [from stand still on warm engine/transmission] does it lock up?
Sorry 'bout the nerdy techie question

From what I understand, our CVT locks up at 20 mph regardless of temps. This is because the CVT belt is doing the gear "shifting," so there is no need for any slippage, except when the engine is idling at a stop light etc. (since we don't have a real clutch to disengage the CVT at a stop).