hey all
 

so i just joined up last week. iv got a 2002 gmc sierra 1500 4x4 5spd 4.3L. when i bought the truck i was getting 14mpg on a good week. after maitence and mods im now getting 20ish. its also window here and im now running with a fiberglass cap and LT studded snow tires. i suspect better millage when the weather warms (and better fuel quality).

unfortunately my daily commute contained mostly up hill one way. doesnt make for potentially amazing results haha.

im also located up in maine at sea level right on the cost.

mods to my truck include a proper tuneup, 3pc aluminum underdrive pulleys, upgrade to electronic injectors, k&n drop in filter with modded air box, flow master exhaust that exits infront of the rear tire, electric cooling fans, and a custom hptuners tune to accommodate a stoich of 14.2 for 10% ethanol.

I'm thinking that unless your driving was all short trip city traffic, you should have been better than 14 MPG as a baseline with the 5 speed. My 98 K1500 gets 13-14 in short trip city traffic, and that's a 5.7L engine and an automatic.

Even if u look on this website, these 4.3s sent that great, specially hills I have around here. Shortly after purchasing it I put new plugs/ wired, cap / rotor, o2 sensors, fuel filter, and the new injectors . That alone made a big difference.

A bad tune will hurt things, even if it seems like you're running on all cylinders.

That's a substantial improvement. (Maybe that's the kick in the *** I need for a new set of plug wires...)

-Bob C.