C4 Question

presicion25 · 03-10-2008, 08:04 AM

Okay,
General C4 Technical question. Between a 1988 4-Speed Manual Transmission and a 1989 6-Speed, does anyone know the difference in RPM's while in the highest gear while cruising on the highway for example? Im wondering because I dont know which is the better transmission, or will a 4 speed waste more gas because it might be at a higher rpm in the highest gear...just wonerding if anyone knows.......Thank You......

zee sting · 03-10-2008, 10:36 AM

The 4 speed tramsmission on the 88 is a 4+3 which has 3 overdrive gears. The overdrive button is on the top of the shifter. You would engage it just as if you were shifting gears. For the most part, I just use mine as a fifth gear. Depress the clutch and hit the button. The only time I ever use the OD is when I am on the highway. I just had it up in Tallahassee for a show this weekend and with it in the overdrive mode, the rpms were at 1700-1900 at 80-85 mph when the OD was engaged. I averaged 25-26 miles to the gallon with the car which also has under skin modes on it. Some love this transmission, others hate it. It is your own preference. I had it in my 85 without a problem and on this one. I have never had any problem with either one. Just keep with the maintainance. My 2003 Z06 in the 6th gear on the highway is around the same in rpms when on the highway at the same speeds. Hope this helps you. Good luck with your choice.

presicion25 · 03-10-2008, 11:23 AM

Quote:

Originally Posted by zee sting

The 4 speed tramsmission on the 88 is a 4+3 which has 3 overdrive gears. The overdrive button is on the top of the shifter. You would engage it just as if you were shifting gears. For the most part, I just use mine as a fifth gear. Depress the clutch and hit the button. The only time I ever use the OD is when I am on the highway. I just had it up in Tallahassee for a show this weekend and with it in the overdrive mode, the rpms were at 1700-1900 at 80-85 mph when the OD was engaged. I averaged 25-26 miles to the gallon with the car which also has under skin modes on it. Some love this transmission, others hate it. It is your own preference. I had it in my 85 without a problem and on this one. I have never had any problem with either one. Just keep with the maintainance. My 2003 Z06 in the 6th gear on the highway is around the same in rpms when on the highway at the same speeds. Hope this helps you. Good luck with your choice.

Thank You Zee Sting. The info was helpful! I was always wondering what the plus three was on the 4+3.....
Thanx Again.....

presicion25 · 03-10-2008, 03:05 PM

Before I forget, what about the other two gears in the +3? You said one is an Overdrive gear, that makes 5, are the other two functional as overdrive gears as well......?

zee sting · 03-10-2008, 04:24 PM

Quote:

Originally Posted by presicion25

Before I forget, what about the other two gears in the +3? You said one is an Overdrive gear, that makes 5, are the other two functional as overdrive gears as well......?

They are over drive gears for 2nd and 3rd. The unit is designed to kick in after certain speeds. This was a move by Chevy in order to deliver the mpg to meet Govt standards. I set mine to kick in only when I want it to. Hence why I referenced it as a fifth gear. That is really the only time I use it.

presicion25 · 03-10-2008, 10:11 PM

Quote:

Originally Posted by zee sting

They are over drive gears for 2nd and 3rd. The unit is designed to kick in after certain speeds. This was a move by Chevy in order to deliver the mpg to meet Govt standards. I set mine to kick in only when I want it to. Hence why I referenced it as a fifth gear. That is really the only time I use it.

OH, Ok Now I understand. Thank You for the information......

dvdcta · 07-19-2008, 01:27 PM

WHAT?????