Window of opportunity opened in my schedule, thinking about reprogramming tonight... maybe to the Premium setting and going up one gas class BUT the big tease is that I'm tempted to enter "37" tire size to see if it adjusts the driveability any when faking a larger tire... I know, near perfect speedo/odo readings will skew, but may do it as experiment.... any quick thoughts before I waste my time? It is hard for me to find time to fiddle, otherwise I'd just goof away.

I'm only "here' for another 45 min...

(currently "4:10" specified rather than no entry even though have rubi/4:10... "regular" /run 89 octane... 34.75" tires - - - this combo made a nice difference, but I'm greedy for more w/o a gear swap to 5:13 yet)

 

That's what I'm wondering if it will do/hoping for in a good way.. i.e, as much or more driveability bene as I got from inputing true 34.75 - Thanks for your input

 

Keep up Posted,I never thought of that.

 

The hypertech does NOT change shift points on the JK, that is from Darnel from Hypertech. So all you will really be doing is making your speedo speed wrong.

 

Well, I reprogrammed the other day and again yesterday........... the speedo (and the MPG readout) changed dramaticaly as predicted.

(BTW, I have to correct a typo on my original post: my first programming tire size input was 34, not 34.75... actual measurement was 33.75" cold, but I input 34 as I thought it might air-up a skosh as the tires heated up or in case I added a squirt for gas mileage)

I have to say that when I first programmed it a month or so ago (prog #1) my impressions of improved driveability over no program/stock with my mods were minor-to-medium, but noticeable (pretty sure it wasn't imagined) enough to make me wonder if a fake gear ratio or larger tire size would net a little more.

All (positive) comments welcome... (BTW, how come no one commented on my musings about the throttle-body-spacer whistle a while back? thought that'd get a flicker at least)


Like I said, after my first programming, obviously having the speedo and odo right-on was a comfort, but it also seemed as though there was slight-but-improved performance. Since it is said that the program doesn't change shift points in a JK, then I'm guessing this must have come from a better fuel profile... and it reported better gas mileage, which I checked by the old fashion fill-drive-devide-miles-by-gallons method.

So, the other day I reprogrammed (prog #2) the same as prog #1, but I entered 37'' for the tire parameter (remembering to only change/test one variable at a time so as to not confuse the testing). The speedo reported much faster than I was going, but I have to say, that I thought I noticed another slight improvement in driveability... certainly it did not elliminate the torque converter annoyance (nothing but rowing the auto like a manual; 5:13s; or a SC will) but it seemed another little bit better... So I thought I was imagining it and after updating the Update Programmer SW and downloading one (unkown) Programmer update via the computer, I reprogrammed back to to prog #1 parameters yesterday and in contrast, it seems like it's missing a little sump'n-sump'n...

Nuts, huh?

Prog #3 will be a trial with the gas parameter set to Premium and then running thru a couple tanks of 89 and then 92 (or +)

All (positive) comments welcome.. BTW, I never got any replies to my "source of throttle-body-spacer whistle" musings a while back... thought that'd get a flicker or two