I have to drive the car pretty long distances sometimes and want it to do as well as it can with fuel mileage. Is anywhere from 14.3-15.1 acceptable? I just don't want to hurt the engine running it too lean.

 

I'd say that cruise with 14.5-15 is acceptable as long as you're not getting any spark retard, probably could go a little leaner than that, just make sure if the delta TPS go up, then the a/f drops down instantly. It will also depend on your EGR functioning correctly or cam lobe overlap if no EGR.

 

I appreciate it Rob. I was keeping an ear out for detonation and didn't hear any and I was running the car around 14.7-15.2. I'll add some fuel back, but I was in a hurry when I did the tuning and I needed the car this weekend.