Hello everyone. I've got a 2000 4x4 with 72,000 miles on it and a 4.7l engine. I live in kansas and it just got cold recently. The first tank I noticed that I got only about 13 MPG. Now that I am sure is cause I would let it run for about 15 min. before I actually drove it all week. but now its warmed up a bit and I dont let it run near as long and so far the same MPG. I also notice a wee bit of a rough idle on occasion. Is this normal in the cold (about 20 degrees or so)? or could I be looking at a O2 sensor or something else? Thaks for all your help.

 

well, poor gas milage just may be depending on how your driving, how long your warming up, etc. mine got 14mpg on a good day before i put some new fuel saving mods on it. the rough idle- i have the same thing on mine. my mechanic said that the trans for this size truck, its kinda standard. so i dont know what to say bout that.

if you want ideas to increase your gas milage, let me know.

 

14 mpg ... do you do a lot of city driving? I get about 18, but that (i would guess) is about 70% Highway.

... if it only idles rough in the cold, it might be the Intake Air Temperature Sensor ( ... shooting from the hip on that)

What kind of Fuel Saving Mods did you do Dodegekota98, and what kind of difference are you noticing?

[sm=icon_cheers.gif]

 

about all i do is city driving. The rough, idk what to say, mine does it all the time- even in warm. the fuel saving mods- new exhaust. im waiting for my cold air intake. i have an ECU upgrade. Im ordering a high flow cat. the exhaust, besides the great sound, can add a couple mpg, and a couple hp. cold air intakes normally give you about a 10-15% gain on mpg. the ECU gave me about 5 mpg gain. and the cat is supposed to give me a gain of 20-30% gain in mpg.

right now, i have on the ECU, and the exhaust. ill be putting on the cold air intake for christmas, and hopefully the cat too. in the future, im going to make the exhaust a true dual exhaust, with larger pipes- for easier breathing.

 

Might I suggest new plugs? I run Bosch platinum in my 4.7 without ever a hitch.

 

what would the spark plugs help? gas milage, or the vibrating?

 

Plugs & Wires could help both ...

Or an aftermarket Ignition coil can help smooth out a rough idle

 

Rough idle is usually caused by an ignition issue, good/new plugs can cure that often, as they're a wear item and need to be replaced every now and again. I'd blame winter gas for a drop in fuel economy as well.

 

The 4.7 plug wires are low voltage with each plug having its own coil, but plugs might make starting better and running smoother. Also run some injector cleaner next fill up, and with every oil change.