Thanks for the replies Micko and Carheir. I ran it wide open the first time I cut and then 3/4 open the second time. I noticed I conserved gas at 3/4 open, so that's why I was wondering about it.
Carheir, I am really enjoying my X1i. It cut my mowing time down from 10 hours to 2.5 hours. Plus I love the zero turn once I got the hang of it! I just wished they would've did a cut-out for name on the back like the Fastrak SD instead of just a Hustler sticker. Other than that (and that's really nothing), I'm loving it!