Aerodynamic drag? or Mechanical problem?

[skiski329]

I have a 3.5 2008 A/C (CVT) and the only upgrades I have on it are hid’s and a stillen front splitter. Here is my problem no matter what the speed I go when I take my foot off the gas, the speed drops much faster than it should. A rough estimate would be that in about 3 seconds I slow down about 5mph. I remember noticing this even before I installed the front splitter. This came back to my attention after I drove a Nissan pathfinder that weighs a lot and is not very aero dynamic and even that suv did not drag as fast as my car is. The first thing that comes to my mind is the CVT, but the car still accelerates with no problem and I feel no “shifting”. Or another guess of mine would be that the brakes are rubbing even when my foot is not on the brake pedal (I don’t know how I can check that) what I did was I disconnected my battery to do an ECU restart but it did not seem to help. Any input on this situation would be great. (Also if any of you have the front splitter. is this to be expected?)

[zilla19]

I noticed that too, but I thought it was because I have wide, grippy sport tires. There's this section of the road that I would let off the gas and just cruise until I get to the school zone. In the AC, when I let off the gas at 40 MPH at a marked point, by the time I get to the school zone sign I'm at 20 MPH. I have driven a Honda Accord and a Jeep Commander through the same section and the two vehicles slow down to 30 MPH when they reach the sign instead of 20 MPH like the AC.

[nissan_star]

what kind of front splitter are you using?

Maybe this is your problem?

[skiski329]

here is the link to the stillen front splitter http://www.stillen.com/product...LTIMAi will post some pic's of it on my car tomorrow.

[Hussain]

maybe its the CVT transmission sort of "engine breaking" or what ever its called.... slightly down shifting the gear ratios or something to help slow down.... just my guess

[Mr. Music]

maybe its the CVT transmission sort of "engine breaking" or what ever its called.... slightly down shifting the gear ratios or something to help slow down.... just my guess

My car does the same thing, and so did the CVT equipped 3.5 coupe and 2.5 sedan that I have driven.

[marlin29311]

Your car is designed to engine brake like this...it's completely normal for the altima, and many other cars as well.

[Pawn]

I think this is normal. I also suspect it is the transmission. To make sure it isn't the front splitter/brakes/etc I would do this:

Get up to a set speed, with transmission in Drive, and let off the gas and see how long it takes to coast down 5 or 10 mph. Then, over the same section of road, repeat the test but have the car in manual mode, and count and see how long it takes for the speed change to happen. Have the RPMs matched around where it would be if the car were in Drive and don't downshift.

If the car takes the same amount of time to slow down in both cases it would be something other than the transmission.

[skiski329]

Seems that my camera is not working so I cannot take a pic of the splitter but you all get the idea from the stillen pictures. And if the engine was designed to brake like this then I am glad that there is not a problem but seems that would kill the fuel efficiency but would be great for the breaks. I will try that test that pawn said

[DaCoupe]

If it really matters that much that you want to just coast , just pop it into Neutral and your good

[Curtieson]

If it really matters that much that you want to just coast , just pop it into Neutral and your good

Ding Ding Ding, that is what I was thinking also.

You bring up comparison to other cars...going from 40 to 30 when ours goes 40 to 20 (No Gas).

But, I bet if you looked at the RPMs our car with the CVT would have an advantage. I can't think threw exactly what numbers would come out to be...but I have a feeling this is all part of the give and take.

[Ricko]

I fell the same thing, I just figured it was the transmission. Try just feathering the pedal when you coast, should stop the problem. my meter still has me at 60mpg when i feather the pedal coasting.

[il duce]

If it really matters that much that you want to just coast , just pop it into Neutral and your good

not a good idea to coast in neutral with a cvt/automatic transmission

[strangebh73]

the cvt transmission is designed to slow the car down when you are "coasting" in gear. This feature is actually electronically changable by your nissan dealer. (i know, i have done it. i used to work for nissan) Using the consult 3 you can change how much it uses the engine breaking. ever notice that when you get down to around 15 or 20 mph the car moves free'r? It's changable go to your dealer, complain, problem solved, they tell you that your nuts, keep calling, call district etc.

and on the matter of coasting with a cvt, won't hurt it. the only time you can hurt the trans is by having the car moving in nuetral with the engine off, because thats when the engine isn't circulating fluid via the torque converter.

happy motoring

[skiski329]

Ok thanks. That is really cool that you can change that. And it makes me happy that this is normal. (this is why Nico is an amazing web site. Thanks again everyone)

[michaelthepsycho]

I think your driving style might also be a factor. The ECU learns the pedal behavior and pattern of the driver and kind of adapts to it.

[zilla19]

Ok, today I drove the same school zone road and this time from 40 MPH mark I put it in Neutral and coasted, and guest what... it dropped down to 30 MPH at the school zone sign like a regular car. So it's the CVT engine breaking that causes the car to slow down more than normal.

[DaCoupe]

Ok, today I drove the same school zone road and this time from 40 MPH mark I put it in Neutral and coasted, and guest what... it dropped down to 30 MPH at the school zone sign like a regular car. So it's the CVT engine breaking that causes the car to slow down more than normal.