I have an 04 STX with no tach. I was wondering what RPMs I am running at 55 60 and 65. When do the RPMs start going above 2k or so? I have read keeping them below 2k is going to get the best mileage. My truck is 100% stock. Thanks for the heads up. Sorry if this is a repeat thread.

 

So what motor? What gears? What tire size? Really hard to tell with out all the info

 

Below is how to find the tach already in your truck as posted in the forum by OTGO2:
Quote: Tachometer. Put key in ignition. But dot not turn or start it. Now push and hold down the trip reset button and now while holding the trip reset button down turn key to on position but do not start truck. Wait a few seconds like 15 I thank and the odometer will say test. Once it says that u can start truck push the trip reset button till ya see tach come up and there ya go. Hope I explained it good if not I'm sure someone else will explain it better.
Originally Posted by OTG02

 

4.6 motor, 3.55 gears, P255/65R17 tires. Everything that is on a stock STX...

 

So the tach will show up whether the trip meter is? Is it there permanently or is temporary, like a diagnostic code?

 

It's temporary, you'll have to do the process every time you turn off the key.

I have the same setup in my truck and at an indicated 65mph my tach shows just a little less than 1750 RPM, and 2000rpm is about an indicated 73-74mph.

Edit: I have the 3.55 LSD, if it makes a difference.

 

Thanks for the info rad. I do most of my driving between 55-65, which from my research should keep me below 2k on the tach. Thanks for the information.

 

Apparently I have 3.73 LS rear end.