6 speed auto question

[Ron_Harris]

I have a 2013 1.8 with 6 speed auto and was wondering if this transmission actually has overdrive as the sales brochure says. Also does anybody else notice that this transmission seems to stay in lower gears if you are giving slight acceleration before shifting. If there is overdrive in there what would the RPM be @ 120 KPH (75 MPH)? On a recent trip to the U.S. I was turning 2200-2500 RPM @ 75 MPH and this doesn't seem like overdrive to me. I tried the GM chat and that was 30 minutes i'll never get back, they don't do technical on chat. I don't want to take the car to the dealer because they'll want to keep it for at least half a day just to look or road test and then tell me they can't duplicate the problem. If anyone has any experience good or bad please let me know, it will be appreciated.

Ron

 

[RMinNJ]

I havent had my 1.4T auto 6speed for very long but I think "2200-2500 RPM @ 75 MPH" sounds about right.

 

[SuperFudd]

Seems about right to me.
My 3.8L V6 Regal turns much slower but fires 6 times per revolution and has gobs of low end torque.

 

[Maddmatts]

My engine turns at 2000RPM at 100km/h and 1800 @ 90. So 2400RPM @ 120km/h should be fairly accurate. My 6T40 transmission has marginally more aggressive gearing than your 6T30, so you should be seeing a little less. Somewhere between 2300-2400RPM @ 120 km/h.

I'm not sure how the overdrive behaves in these cars. They do have lock-up torque-convertors but I never feel it engage like in my last car.

 

[SuperFudd]

Mine (see below) has a lock up torque converter?
I would not have guessed that it did.

 

[Maddmatts]

Straight from gmpowertrain.com: "...the 6T30 uses a single-plate lock-up clutch...The single-plate converter clutch uses GM's electronically controlled capacity clutch (ECCC) technology to help reduce engine vibrations and ensure smooth operation." Says the same thing for 6T40/45's as well.

The ECCC is either so smooth that we can't tell it's there, or GM decided not to use the capability on our platform for one reason or another and consider something else as "overdrive".

 

[SuperFudd]

5th gear is 1:1 so 6th is considered overdrive, I suspect.

 

[TMac]

I was wondering the same thing. I know that the 1.8 has a 5 speed where the 1.4 turbo has a 6 speed. But the automatic is a 6 speed for both :\