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5.3l Afm Poor Fuel Mileage?

houde3050

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houde3050 Enthusiast

houde3050

Posted
Posted

Just curious if anyone has had this problem, i've got an 08 silverado with the 5.3L AFM engine and the last month or so it seems like its been using fuel at an abnormaly high rate. I travel mostly on the hwy and you can almost watch the gauge going down. I've got a k&n intake kit and dual exhaust but those are both over a year old so i'm trying to rule those things out. Any input would be great, before i go to the dealer.

newdeal Enthusiast

newdeal

Posted
Posted

I have afm on my truck its a brand new 2010 and it barely even comes on. I can have the cruise on on the highway and its still not on it sometimes will come on if I am going down a hill but often v8 will come back on even then. definately its in v4 alot less than I thought it would be

redvett Senior Enthusiast

redvett

Posted
Posted

I would check and see if the gas station your using has changed from E10 to E15 recently and since its cold weather the winter gas will affect fuel economy.

nick3941sd Enthusiast

nick3941sd

Posted
Posted

Now i know they are not the same brand but my Volant intake was killing my MPGs until i got it tuned from blackbear. Justin said the injectors were just dumping fuel in it.

 

A few weeks ago in PIT i got a BB tune and had the AFM turned off and noticed an instant gain in MPGs and power.

 

Just food for thought. I never dealt with K&N before but maybe its causing the same problems. Id look into a BB tune also.

Daryl LBZ Senior Enthusiast

Daryl LBZ

Posted
Posted

Dump some Lucas Fuel Injector Cleaner in your tank and see if it helps. I know it has on my truck and my Camaro. It seems like since they started putting 10% Ethanol in the gas the fuel injectors get dirty faster.

jro909 Senior Enthusiast

jro909

Posted
Posted
Dump some Lucas Fuel Injector Cleaner in your tank and see if it helps. I know it has on my truck and my Camaro. It seems like since they started putting 10% Ethanol in the gas the fuel injectors get dirty faster.

 

 

ethanol is a solvent, if anything its cleaning shit out

glnisbet Enthusiast

glnisbet

Posted
Posted
Just curious if anyone has had this problem, i've got an 08 silverado with the 5.3L AFM engine and the last month or so it seems like its been using fuel at an abnormaly high rate. I travel mostly on the hwy and you can almost watch the gauge going down. I've got a k&n intake kit and dual exhaust but those are both over a year old so i'm trying to rule those things out. Any input would be great, before i go to the dealer.

 

 

I have noticed also a drop in my fuel mileage going from an average of 19 down to low 16. Gas has an increased level of Ethanol (winter blend) right now. Price is up and mileage is down.

music Senior Enthusiast

music

Posted
Posted
ethanol is a solvent

 

Gasoline is a solvent. Water is a solvent. Heck, any liquid is a "solvent' for some compound. (sorry, couldn't resist :fume: ) The trick is finding the right solvent for the issue at hand. It is my understanding that the better "injector cleaner" uses a Chevron-patented additive that dissolves "gummy organic deposits" on the intake side that standard solvents don't, and also that dissolve "oxide deposits from combustion" on the exit side. That's the idea, at least. If good quality gas is used, it shouldn't be needed.

Daryl LBZ Senior Enthusiast

Daryl LBZ

Posted
Posted
Dump some Lucas Fuel Injector Cleaner in your tank and see if it helps. I know it has on my truck and my Camaro. It seems like since they started putting 10% Ethanol in the gas the fuel injectors get dirty faster.

 

 

ethanol is a solvent, if anything its cleaning shit out

 

 

 

 

 

 

IDK just something I read on the net, and also noticed in my vehicles. Guess it could just be the gas around my area.

txab Senior Enthusiast

txab

Posted
Posted

Every supplier changes the fuel blend for colder conditions. My mileage has dropped off since they began doing this years ago.

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