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Thread: Poor MPG. New plugs, wires next?
08-27-2013, 09:23 PM #1
Poor MPG. New plugs, wires next?
My Avalanche has been averaging around 12 MPG per tank. It's 4x4 with 3.73s, stock ride height, with Diablo 87 octane tune, and a K&N CAI. I made sure I reset the computer by disconnecting the battery after I installed the CAI. Anyways, last weekend I decided to clean the MAF sensor and change out my plugs. These were the stock plugs with 70k miles on them. I replaced them with Denso Platinum TTs (PT16TT) because I figured I'd trying something different. Next might be wires if my mileage doesn't improve much. Any other ideas? Also, what do you think of the plugs below?
-2008 Chevrolet Avalanche LT 4x4 w/ Diablo inTune 87 Octane, K&N CAI
-2012 Kia Soul !
-2003 Kawasaki Ninja ZX-6R 636
08-27-2013, 10:06 PM #2
Are you throwing any codes?
If at first you don't succeed, chances are, you are using too small of a cheater bar
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08-27-2013, 11:15 PM #3
08-27-2013, 11:27 PM #4
Yeah. Mine looked like that after 40,000. But my knock sensors need to be replaced. You don't drive like a bat out of hell I'd assume. Does it have the 5.3 or 4.8?
08-28-2013, 12:46 AM #5
I don't think those plugs look that bad. Other than changing plugs, modern engines don't require much of a "tune up" like they used to. Change the plugs and fuel filter, clean the air filter and keep the tires aired up (go a little above the recommended air pressure on the door, maybe 5 to 10 pounds) and you should be getting most out of your fuel mileage.Clint (TX) 2001 Silverado LS 4.8L auto 2wd ECSB [GARAGE]
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08-28-2013, 03:43 PM #6
08-28-2013, 04:33 PM #7
The plug wires on the 5.3L V8 engines are really short, so they are really easy to replace. I don't know how much they cost, but it can't be that much.
2013 Silverado LTZ White Diamond Crew Cab
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08-30-2013, 04:17 PM #8
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Took the truck to the dealer today. They said they checked everything and it all seemed fine. maybe the truck is just that bad on gas. oh well. I went ahead and changed the plug wires as well.