[cole97henry]

I hate to beat a dead horse but I honestly need some other opinions. I have a '99 GMC RCSB with a 5.3 4x4. All stock except for flowmasters and 285 nitto terra graps on stock rims.

Granted I don't drive the easiest buy even on long trips (200 mi running 65-70) I rarely see over 14 mpg's.

So what gives I see people brag bout 17-19 on 03-06 and I don't see the difference?

 

[Graystone]

Tune up. And keep your foot out of it. Clean your maf

 

[cole97henry]

So are these high teens true?

 

[Graystone]

I could get 20 with my 2wd 4.8 but I drove like an old lady and a lot of highway

 

[99_Sierra]

I was getting 19 with my stock wheels and like a 275 tire on the highway. My truck is also an all original 326,000 mile 99 z71 with a 5.3.

My 2wd 4.8 gets damn good gas mileage on the highway


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[chevdm6]

I was getting 19 with my stock wheels and like a 275 tire on the highway. My truck is also an all original 326,000 mile 99 z71 with a 5.3.

My 2wd 4.8 gets damn good gas mileage on the highway


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Cant agree more. I have gotten almost 22 mpg with my 4.8. I drove from jackpot Nevada to Vegas which is a 460 mile drive and I did it in 1 tank. There was still like 5 almost 6 gallons left in the thank when I filled up in las vegas.

 

[FiestyZ71]

Is ur speedometer accurate with those tires

 

[cole97henry]

Within mile or two I believe but I'll gps it later this evening

 

[FiestyZ71]

Within mile or two I believe but I'll gps it later this evening

Get the truck tuned to the correct tire size. Tune up. Cat might be slightly clogged.