2000 s-10 Vortec bad fuel economy

[jlemay]

2000 S-10 ZR2, 3 dr, 4x4, Vortec V-6, seq injection, 3:73 rear gears, gears between rear and trans act like low gears thou, @55 mph runs at 1700 rpm, fresh oil in all pumpkins (synthetic), plugs and wires look like new

1. What is the MPG supposed to be for this truck?
2. Would duel exhaust improve MPG, and how much?
3. Would any add on after market parts improve MPG and how much?
4. Brand new Goodwrench tires with appropriate size for truck by door panel.
5. Engine runs good, dont miss, good power, etc, so i think the compression is decent.

edit:

1. automatic
2. 105k miles
3. bought about 6 months ago, no tune up done
4. donno brand name used atm
5. 3 new oxygen sensors
6. have not checked fuel pressure/leakdown, but truck runs like a top, dont miss etc
7. new air filter
8. will replace fuel filter in about ohhhh, 10 min, lol
9. no SES codes going on

If i did a tune up what would you suggest?

edit 2:

fuel pressure perfect and does not have a distributor cap, but coil instead

[old_master]

Manual or automatic transmission?
How many miles on the vehicle?
How many miles since it was last tuned up?
What tune up parts were replaced?
What brand of parts were used? (4.3L is fussy)
Have the oxygen sensors been replaced?
Have you checked fuel pressure and leakdown lately? (Must be within specs)
How many miles on the air filter?
How many miles on the fuel filter?
Is the Service Engine Soon, (SES) light on or does it blink when accelerating?
If so, have you retrieved any Diagnostic Trouble Codes, (DTC's)?

[old_master]

It's due for a tune at 100,000 miles. I would recommend AC Delco 41-993 plugs with a gap of .060". These things are real fussy when it comes to caps: AC Delco distributor cap and rotor, put a dab of silicone dielectric grease on each terminal, inside and out, of the cap. While the cap is off, make sure the vents are clear, (no debris). Autolite Professional Series plug wires, (better and cheaper than AC Delco). Fuel delivery is critical on these engines, low pressure or excessive leakdown WILL cause problems. The fuel pumps are good for around 100,000 miles. If/when it needs a pump, don't cut corners here, AC Delco or Delphi ONLY. To check fuel pressure and leakdown: ignition in RUN position, engine off, fuel pump running, pressure must be 60psi to 66psi and must remain above 55psi for 3 to 5 minutes.

[jlemay]

updated, check top post, can only update when im off work, etc

[old_master]

2000 4.3L has a distributor, and a cap and rotor. It's right next to the fuel pressure test port, can't miss it.

[viggy58]

what kind of mileage are you getting?

i get 22-25mpg, but i have a 2wd 5 speed. you should prob expect 16-20mpg depending on 4x4 usage, i would assume