I have a 09 Tahoe, I have the 87 tune installed but I run 89 octane. Can I install the 93 octane tune and still run 89? What ill effects will that have? As I understand that there is some timing changes in the 93 but not in the 87.

no, there are no user adjustable TM settings for the engine/ecm tune.. TM is already disabled in the preset ecm tunes.. you can only change the tranny/tcm upshift TM.
Thanks, I thought I read that here before but I wanted to make sure since someone in another forum said he seen it. Must not have ...

Quick question, On the i2030 I have an 09 Tahoe 5.3L with the 6 speed. Is there a TM setting anywhere else besides the Upshift TM in the TCM? I heard from one person that on his tuner with his 09 that he seen one in the ECM area.

So really no benefit other than the feel of a firm shift and the old school 2nd gear chirp?

So how does the firm shifts and TM off feel to you guys that run the 6 speed?

Can someone please explain the difference in stock/firm/hard shift options? What improvements does changing them have other than perceived feel?

Great post. I was just about to ask the same question on my 09 Tahoe 5.3L 6 speed.

That's what I did. I researched this forum a bit before and I gathered that the easy tune bug wasn't fixed yet. I didn't do any other mods other than DOD/AFM disable. I'll do the same with the 93 tune. Once I get the cash to make the 5.3 breathe freely, I'm going to opt for a custom tune.

Thanks,
I'll give it a few days and see if it levels out. It's not bad, just noticeable.
I may go with the 93 after this tank of fuel. How empty of a tank of 87 before filling up with 93 to avoid any issues?

I have an 09 Tahoe and I did the 87 tune with no other modifications except AFM disable. I have noticed a slight surging/lack of smoothness when I ease into the throttle at take off when the engine is not up to temp. It almost seems like a little miss. It did not do this before tune.
Also, is there ...

I registered my tuner and I used the number that was on the sticker right above the date sticker on the box. It had a combo of numbers and letters under a bar code. Did I use the correct number?