anyone got any helpful hints on how to improve my gas milage? I drive a 99 f-150 with a 5.4. I put a cold air intake, throttle body spacer and removed my muffler, still gettin pretty poor milage though my last tank i ran in 4 wheel drive for quite some time.

 

So what do your consider "terrible" MPG? I get about 15 MPG with mixed city/hiway (not a 4x4).

Here's some info straight from the FAQ link at the top of this forum.
Welcome to FTE!

Q: I'm getting terrible gas mileage on my truck. What's wrong?

A: These trucks are notorious for poor gas mileage. Unless you’ve noticed a drastic decrease in your normal mileage, your low MPG is probably not related to a mechanical fault. The fuel economy numbers on the window sticker are determined by the EPA based on a standard testing method under optimal conditions. Your normal driving habits and routine probably in no way resemble the EPA’s test.

There is no single magical item that will “fix” your mileage. Most users on this site combine several mechanical enhancements. It’s all about how much money your willing to spend up front to save some over time. Here are the most commonly recommended methods for increasing mileage.

- K&N high flow air filter. This type of air filter permits a higher rate of airflow into your engine, while still providing adequate filtering. The easier it is for your engine to breathe, the less it has to work. Best of all, the filter is re-usable, only needing to be cleaned every 50,000 miles. This means you will never have to buy another filter again. There has been much heated debate on this site regarding K&N’s. In the end, most users find a slight gain in HP and a 1-3 mpg increase.

- High-flow exhaust. Back-pressure in the exhaust system reduced engine performance and hence worse mileage. A performance exhaust permits easier expulsion of exhaust gasses, which makes it easier for the engine to work. Typically users prefer FlowMaster mufflers, but there are many options. In addition to the muffler, the exhaust pipe size and header size have a lot to do with the amount of back pressure on the engine. Check out the Exhaust forum for a discussion of different options.

- Plugs and wires. A quality set of plug wires and spark plugs help to keep your engine producing maximum horse power, which in turn helps your MPG. There are many types of plugs so your choices are endless. You can never go wrong with the manufacturers’ recommendation, but there are performance plugs available if you want to spend the money. Most users recommend some type of double platinum plug, such as the ones made by Motorcraft or Autolite. For tips on replacing your spark plugs see https://www.ford-trucks.com/forums/s...d.php?t=104027

- Electric Cooling Fan. Your stock truck uses a cooling fan driven by your engine. Powering the fan clutch and the fan with all its blades needlessly wastes horse power that could otherwise be used to power your truck. A popular, albeit expensive solution to this is to remove the stock fan and replace it with an electric fan. There are several aftermarket electric cooling fans designed for this purpose.

- Tonneau bed cover. The theory behind this is that your tailgate creates drag at high speeds. The Tonneau cover provides an aerodynamic surface to air to flow across the back of the truck. You won’t find much mileage increase in city driving, but at highway speeds you may pick up 1 or 2 mpg.

 

I get about 10, but thats with a heavy foot and city driving.

Its always good to make sure everything is tuned up good, but for the most part unless you like the sound of exhaust and intake and the look of a bed cover or you're looking for more power (which is fine, i have some of them items and plan on getting more but thats because my primary reason is sound or looks milage is just a bonus) i don't think the items will help much because i doubt you'll recoup the costs of the items without driving A LOT.

 

im not sure that really answered my question

 

Running in 4WD = poor fuel economy ususally because you are in difficult areas (mud, snow, etc).

 

Keep your foot out of the throttle.

That always works for me.

 

or i could just not drive the truck which is working out pretty good, now im driving my dads powerstroke haulin supplies.

 

Well you still haven't told us your actuall MPG?

 

im gettin about 13 in the city and about 18 runnin down the interstate. alot of the mileage is driving on I-70 over the colorado mountains.

 

So it's not really so bad, huh? It's a full size truck with a v8, sorry but that's part of the deal.

 

Thats pretty damn good gas mileage. I get 11-12 with an '03 Ext Cab 4X4 in 2wd drive mode. I've got the K&N and a Borla catback. I don't hammer it usually either. I don't see me hitting 18 mpg, even on the highway. And thats with a tonneau cover on.

 

we drive trucks...not to get gas mileage...did u say rockies...that sounds like an up hill battle...i got a preditor tune, flowmaster cat back, aem cold air intake it honestly didnt make a huge difference in mpg...i got a 150 nos shot that helped...well it made me feel good

 

Ok guys here it is, i will stop complaining about gas mileage. 500 miles on 23 gallons of gas, ill let all of you do the math.

 

Yeah...I wouldn't complain anymore about your mileage. 21 mpg in a 4x4 with a 5.4 is pretty dang good. I get 21 to 23 on the highway with my 4.6 auto.

 

21mpg and you are complaining?!? I just went 600 miles on 40.5 gallons. 14.8mpg give or take. I would glady take that 21 any day.