Want to know if theres anything else i can do to get more mpgs out if my blazer?

I have a 95 Blazer Ls 156,xxx. reman engine w/ under 19,000 on it now was intalled in 05 w 0miles. since i had it in feb. 2010, i changed my spider injectors and transmission fluid and add lukes adtives ($817), 2 front Tires($177), alignment($85), Tune-up labor($20), spark plugs and wires rotor cap,($80), oil change kit: purple oil stuff with lukes addtives($60), rear brake adjustment($21), steering fluid additives(its squeald)($8), front rear wipers($20) then i added back up light to my hitch($40), Leather seat expect drivers seat($40)(yes $40 some was sell on craigslist), keyless remote($15), GM key($6),new aftermarket cd player(came w when bougt). has orignal shocks took off side trim

 

The search feature should turn up quite a few results to this question. Using "improve+mpg" as a search term (without the quotes) should turn up some results.

 

once in awhile when i'm drive anround and go to stop i hear a noise like its locking up but they work fine.? Also my steering vibrates/shakes wheni hit 70 mph but you can tell when it hits 80.

 

power driver seat, all 4 door panels, running board. not the pipe kind but the kind that goes over the rockers.

 

how many miles per gallon should i be getting if the run the a/c the whole time?