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Inaccurate Fuel Gauge?

cskoop

By cskoop
in Ask A GM Technician

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cskoop Enthusiast

cskoop

Posted
Posted

Not to sure if anyone can help me or not, I have an 08 LMM crew cab SB, have 2200kms on her, my fuel light came on so filled her up but only could get 67 litres or 17 gal. drove around for 48 kms and already I was half way between 3/4 and full. Drove 212 kms and and only has 1/4 left? again filled her up but only could get 15 gallons in it. Fuel sitting right at the top of the filler tube. but again drove around and it started to move off full within 40kms? Is there problems with the sending units or gauges in these trucks or a TSB for a problem like this. The fuel mileage that I have calculated is 16.5 liters per 100 kms or 14.5 MPG . I am hoping to get alot better fuel mileage than 265 kms on a tank of fuel. Hope this makes sense and thanks again for our help.

 

Coop

Calgary Alberta

08 LMM CC SB 2500

hubbycap Senior Enthusiast

hubbycap

Posted
Posted

I've found my NBS fuel guage to be spot on. I'm unaware of a TSB but you obviously have a warranty issue, use it. On your fuel consumption, my '07 5.3L was 13-14 the first 2K miles and has steadily improved w/break-in to around 17mpg. Now at 8 months and nearly 14K. Got 21 mpg on a pure interstate road trip last weekend, 70-80mph.

Ranger Senior Enthusiast

Ranger

Posted
Posted

I think there's a little gap between "actually empty" and "just about empty" to allow for the people who always run the whole tank out...I've had mine all the way down to Empty before and when I filled up it took about 22 gallons. If I fill up at the 1/4 mark it's generally around 17.

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