lq4 timing

anyone have any good results raising timing on this motor? i'm looking for 87 octane timing only i have a 2003 express van. wot its only commanding -1 degree in the low octane chart. also is there anyway of getting more mpg on highway? like commanding a leaner mixure?

anyone?

To start the HIGH octane tables are used until knock is sensed as far as I understand. The timing tables are very weak in these stock tunes. But that van is also a heavy bitch so id watch where you add timing to.