I just returned my 07 GT to stock tune because I failed inspection. I want to leave it stock but I have this question: I have 4:10 gears and 295/45/18 tires so my speedometer is off now. How can I make my speedo read correctly without a custom tune that alters engine specs? I asked my local SCT Tuner guy and he wants $150 just to make the speedo correct.

 

maybe try the stealership? They will probably come in higher than sct, but its worth a try.

 

The only way to correct the revs/mile is a re-tune. However, you can just live with the speedo being off for a few days before you have it re-inspected.

Dustin

 

That what I did..just lived with it.

 

Make a new speedo tach backround with updated spots for the mph and replace the old one?

 

As it stands now, I'm not going back to the tune. It gave me a lot of drive line vibration around 2500 rpm and I kinda got tired of it. I'm gonna stay stock for a while and see how I like that. So far, I'm liking it better due to the smoothness of the engine and drive line. Besides, if I want to go real fast I'll drive my other car:

 

Yup, the other car can def make you go fast.

 

If you can afford a Stang and A Vette then you should be able to afford a hand-held tuner (SCT) Then you can change gear ratios and tire revs per mile yourself plus what ever else you want or not.....JMTC

 

I'm not sure you're understanding my question so let me try again. I own the tuner pictured below and it holds a custom tune. I recently used this tuner to return my car to the stock tune and I want to keep it stock. However, since I have 4:10 gears and bigger tires, my speedometer is now off. I asked my local SCT guy if he could help and he wants $150 program my tuner so the speedometer reads correctly. I'm not trying to sound cheap but $150 FOR A SPEEDOMETER ONLY TUNE? There's got to be a cheaper and better way.

 

I just lived with it for 2 weeks. I knew I was 5-7mph slower than what it said, so I just always kept that in my mind. It's not really a big deal. I also have 4.10's and 295/45/18's. I guess if you wanted to you could hit up Bama for a tune that will pass emissions, IIRC the problem is that they turn off the rear o2 sensors so it will not go through the proper drive cycles to make it ready to test.