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texanidiot25 · 08-02-2011, 12:34 AM

It's actually used to improve fuel economy for EPA testing on many cars.

Since the 90s, GM has used it on their 6spd muscle cars in the form of a forced 1-4 shift. Under light load conditions, when you shift from 1-2, a solenoid clicks in and the gate for 2nd slides you into 4th. It'll do this at light load and under 25 mph on my car.

It was to improve the fuel economy in EPA testing, and is used today to avoid the gas guzzler tax on many cars.

I found it annoying, since I skip shift into 3rd anyways. It locks out third as well. On the GM cars, it's easy to disable. It wasn't lugging the motor per say, but it wasn't always an optimal gear for what I was doing. You could hold the trans in N for a second and it would disable the skip shift, but that kills momentum.

Of course, big GM V8s have enough torque to drive just fine in 4th gear at 25-30mph.

08-02-2011, 12:34 AM	#13 (permalink)
texanidiot25 Master EcoModder Join Date: Jul 2008 Location: Cypress, TX Posts: 331 Formula - '96 Firebird Formula/Trans-Am 90 day: 19.31 mpg (US) Thanks: 8 Thanked 31 Times in 18 Posts	It's actually used to improve fuel economy for EPA testing on many cars. Since the 90s, GM has used it on their 6spd muscle cars in the form of a forced 1-4 shift. Under light load conditions, when you shift from 1-2, a solenoid clicks in and the gate for 2nd slides you into 4th. It'll do this at light load and under 25 mph on my car. It was to improve the fuel economy in EPA testing, and is used today to avoid the gas guzzler tax on many cars. I found it annoying, since I skip shift into 3rd anyways. It locks out third as well. On the GM cars, it's easy to disable. It wasn't lugging the motor per say, but it wasn't always an optimal gear for what I was doing. You could hold the trans in N for a second and it would disable the skip shift, but that kills momentum. Of course, big GM V8s have enough torque to drive just fine in 4th gear at 25-30mph. __________________ Lets see how far it can go "All I know about music is that not many people ever really hear it. [...] But the man who creates the music is hearing something else, is dealing with the roar rising from the void and imposing order on it as it hits the air. What is evoked in him, then, is of another order, more terrible because it has no words, and triumphant, too, for the same reason. And his triumph, when he triumphs, is ours." -Sonny's Blues