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JBVowner2b
03-07-2004, 04:54 AM
Hi all,

Can someone please explain to me the purpose of the 1st to 4th shifting on the CTS-V?

My understanding is that if you are driving too slowly (below 20 mph) in 1st gear, the car will automatically shift into 4th gear. This is supposedly to save gas somehow. But I don't understand how this saves gas. Also, wouldn't this stall the car due to the low rpm that would result?

I'm no car expert, but this doesn't make sense to me.

Thanks to all. I enjoy reading here. It is great to see the enthusiasm about the V car, and as a potential new owner, I appreciate all the insight you all provide. Especially you dealers.

JB-V-owner-2b

bnunnally
03-07-2004, 09:00 AM
These engines have plenty of torque to pull the lower gear, so there are no problems with stalling.

The skip shift allows the car to get to a lower rpm for the same speeds; when the engine is running at a lower rpm it uses less gas than if it is at a higher rpm.bruce
<img src="http://caddyinfo.ipbhost.com/uploads/ctscrest.jpg">
CTS 3.6L Light Platinum/Light Neutral

JohnG
03-07-2004, 10:15 AM
While the Skip Shift does save gas in normal driving (as Bruce indicated above) where it really shines is the EPA test cycle - it keeps the car out of the Gas Guzzler Tax area. Thats why it won't kick in when you have the throttle open more than a certain % & won't kick in if you rev over a certain RPM in 1st - because the EPA testers never do that, so they always get the skip shift to 4th.

In any event, a $30 skip shift elminator plug, or a $.50 resistor can kill the skip shift so you never have to worry about it again.

JBVowner2b
03-07-2004, 11:05 AM
Thanks Bruce and John. I get it and it makes sense now.

Do either of you, or anyone else, know at what RPM level in 1st gear kicks in the auto-shift to 4th. I keep hearing about this but I don't believe anyone has stated at what RPM level causes this to happen.

And why all the way to 4th? Is there anything magical about that? Why not to 2nd or 3rd? Maybe its the EPA test that John mentioned. Seems like an excessive shift.

Thanks,

JB-V-owner-2b

Daniel
03-07-2004, 04:59 PM
The skip shift solution is not new to the CTS-V, it is common with most american performance cars using the Tremec T56 6-spd transmission. These include Corvettes and Vipers. Couple of points:

1. Like mentioned earlier, it is designed to overcome an EPA test, and the obvious solution is to take advantage of the engine's torque... it drops a guide into place so your pull down to 2nd gear ends up in 4th.

2. It is not an auto-shift, it only forces the shift from 1st to 4th.


3. It only kicks happens when the engine is up to temperature and the vehicle speed is in a specific range in 1st gear (can't recall it is in the manual).

4. Some choices to overcome: stay in 1st a bit longer or obtain a cheap bypass kit.

FYI: The Tremec T56 is also a double overdrive unit (both 5th and 6th), again for EPA and economy purposes. 6th gear is meant for economy, while 5th will get you to top speed.

Post any other quetsions.

JBVowner2b
03-08-2004, 03:31 AM
Thanks for the explanation Daniel. I realized after I posted that it couldn't be an auto-shift, otherwise the shifter would physically be in 1st gear, while the car is in 4th - that didn't make sense.

I realize now that the car forces you into 4th when you shift out of 1st, thus it would have to be 4th and not 2nd or 3rd due to the positioning of the shifter.

I got it now. Thanks,

JB-V-owner-2b

timberline
03-15-2004, 03:47 PM
John,
From where do I buy the parts, how are they installed and who does this install if I don't?


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