2006 ext cab 5,3 with a fiberglass cap.
K&N filter, I averaged 16.3 mpg round trip to vegas and back, 3800 miles.
It seems since I put on a flow master it dropped 1.5 mpg
any suggestions if I should go to headers and race cats.

Yeah I know its a truck and didnt buy it for fuel ecomony, but wow, mileage really sucks
What are you all averaging??

 

I have the same truck. Drove it to Missouri and back and got 19.8mpg. I also have K&N and flowmaster catback. How many miles do you have on it?

 

I have an 01 Silverado and i average 18-21 on the highway. I have a K&N FIPK kit and no muffler just cats.

 

Your average mpg info is no good w/o your average MPH info !

How fast and agressive your drive seriously affects mpg's.

I only get 16mpg's on my 5.3L 2WD Sierra, but in spite of mostly freeway driving, the rush-hour stop-and-go and aggressive driving I do kills the potential 19-20 that some get.

I am very VERY rarely in a situation where I can (or will) drive at 65-70mph to get that holy grail of 19-20 mpg!


.

 

THAT IS CORRECT MilleArp,
I

 

Tat Man, I have 06 Crewcab 5.3 3.73 rear Tonno cover. Put an Airaid Filter kit, superchip, upgraded to premium Gas It gets 21.8mpg on the highway when I keep it under 70 without the cruise on and not towing my boat. My next upgrade is a catback system.

 

big difference in 68mph and 72...gotta keep that foot out of it

 

I had it on cruise and 81mph.
If I hold it at 60 I get 18.5
I dont drive aggresively, around town I get about 11 mpg.
Mileage on truck is19092

 

Its your driving dude!!!!

SLOW DOWN!

 

A vehicle has a certain turning point in drag when it reaches a certain speed. For most cars this pointcomesat about 60 mph. The faster you go, the more your engine has towork to keep up to speed. What people don't realize about trucks is that the engine is powerful, but it also has a lot of weight to pull. Now, because these trucks are so big and heavy, one must focus on these two factors: weight and drag. I've searched several websites and forums and I have come up with a few very simple modifications that you can do yourself to improve mpg. First thing, clean your vehicle! There really is no explaination neccessary. Also, if you have a toolbox, try to slim down what you have inside there unless it is for emergencies.Although weight is a major factor, it is not difficult to make the difference yourself. Drag can also be handled by the owner with a bit more work. One of the coolest home-made accessories that I have seen is the skid plate. You can make this plate out of most materials. The skid plate is basicallya sheet of metal that is custom cut(by you, hopefully)to bolt over your undercarriage and greatly reduce drag. Make sure to cut holes or slits for the front differential. What is so great about this modification is that you can adjust according to what type of truck you have. If you have a stock truck and you want the skidplate strictly for saving some mpg's, then you should use about 1/4" aluminum. More off-road trucks should use steel. One of my friends even used carbon fiber for his Sierra. If you can, try to tuck up your exhaust system. Some spoilers help to reduce drag, but really look into what you're buying. A bed cap or topper will greatly reduce drag, but that costs money. Try just taking off the tailgate or even replacing it with a "tailgate" http://www.thetailgaters.com/