my blazer weighs about 3200 lbs.around about the same weight?

 

i'd say so, i get about 20, but i need to get my car weighed......i think they're anywhere from 32-3800, depending on weight removal and whatnot.......you should be pretty good then.....i'm not sure how much of a change the added drag of the truck shape would cause in mpg, but i can't imagine it would be too drastic.....

 

Ditto, what he said.

 

We have had our '98 LS1 for a few weeks now and it seems like we are only getting 14-16 in the city?

All stock as far as I know and I put new plugs in it the day we bought it.