Fuel Help

[Matt414]

Hi everyone! I am new around here so go easy on me if this topic has been covered before. I have a 1998 GMC Sierra with a 5.7, just hit 152,000 miles. Still runs great, but I have a problem. My fuel mileage has slowly dropped off over the last 6 months or so. My last tank, I just filled up today, I got around 14 mpg. This was all around town, but I used to get much better around town, almost 17. Any thoughts? Thanks in advance.

[Mr. Smith]

Change the fuel filter.

 

 

Hi everyone!  I am new around here so go easy on me if this topic has been covered before.  I have a 1998 GMC Sierra with a 5.7, just hit 152,000 miles.  Still runs great, but I have a problem.  My fuel mileage has slowly dropped off over the last 6 months or so.  My last tank, I just filled up today, I got around 14 mpg.  This was all around town, but I used to get much better around town, almost 17.  Any thoughts?  Thanks in advance.

 

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[RyanZ71]

Fuel filter, new plugs and wires, do the PCV valve, and do an oil change while your at it (nothing thicker then 10W30 and thinner then 5W30) eliminate that stuff now and then we can go from there.

[snoman]

Fuel filter, new plugs and wires, do the PCV valve, and do an oil change while your at it (nothing thicker then 10W30 and thinner then 5W30) eliminate that stuff now and then we can go from there.

 

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And while you are at it change the rear axle with new 75w90 and the front pig with 80w90, the Tcase with new ATF fliud and a tranny fluid and filter change too and get all of your lubes fresh.