Well, did a quick caculation and my last fill of gas and got a respectable 15.4 mpg. My driving conditions consisted of stop and go traffic and a slight lead foot. The 33's with a 3:55 rear end hurt me a little bit but also note that I drive a 4X4 with a 5.4l V8.

The truck is tuned with Superchips tuner and I set it at the "performance" setting with almost stock shift points and maximum firmness. Intake and exhaust mods are an Airaid intake with heat shield and shorty headers + 3" straight pipe from the cats. Overall, I am happy.

 

how do you like that superchips tuner? im torn on which one to get if any?

 

I have the old 1715 tuner. Works very well but there are better versions now.

 

Not bad mileage at all i think i get that around there with my truck in the city i dont got that much for mods 2.25 dual exhaust w/ flowmaster 40s

 

2wd L/S 3.55 chipped 285/75/16's 5.4L lucky if I get 12 mpg

fortunately my commute to work is only 6 miles each way...

 

i have a flowmaster, 40 ser. and i have a big foot, so i get about 15- 16 on a good fill up.

 

I'm curious as to wether a set of 4:10 gears might help with city driving. I know with the taller tires and 3:55's highway mpgs are sure to be in the 18-19 range.

 

Thats not bad milage at all considering you have bigger tires than stock and the tuner set to "performance".
I dont think my mostly stock '99 gets any better milage than that.

 

Ya'll are doing good. Im only getting about 12-13 with my 4.6L 4x4 w/ 33's and a very light foot lately....

Makes me want a V10. If Im going to get that kind of mileage, I atleast want some performance out of it. My truck wont even get out of it's own way...A elderly man in an electric wheelchair passed me in town yesterday flipping me the bird!

 

Xtrford, You would think the taller tires and a 3.55 combo would help on the hwy. but you would be wrong. I have an '02 supercrew FX4 with "33's". and it still sucks. I dont know what size wheels you have but my truck has the stock 17" FX4 wheels, the stock 265/70/17's and the new 33x12.50 17's are with in a quarter inch of eachother in overall height. They are a good bit wider though. Mathmaticly "on paper" taller tires and a shorter gear (numericly smaller) would equal better MPG, but take into consideration that you are dropping the engine further below its power band. These trucks are already at or below their power band from the factory. There are countless posts discussing MPG gains after installing a set of 4.10 gears. Gasoline engines need to spin faster to make the power needed to push our heavy trucks. As an example, how many times have you heard Chebby owners bragging about their trucks getting beter mileage than ours? Most Z-71's come factory with a 3.73 gear. At least all of them I have seen do. I am fixin to get 4.10's swapped into my truck because I'm sick of getting 12-14 MPG, and as ATC said this thing has a hard enough time getting out of its own way unloaded. Put a trailer behind it and you might want to consider turning on the four way flashers!

 

wouldnt 4.10 gears, 33in tires and 75-80mph on the hiway be a bad combo for mpg? i would think that your rpms would be 4-500 higher using the 4.10 gears as opposed to 33's and 3.55 and 75-80 mph? all i know is in my o2 fx4 with 33's and 3.55 on the highway, i do at least 80mph up to 90 and it gets about 14-16 on the hiway and i would think it should be getting worse mpg but the rpms are only like 2ooo at 80 and 2400 at 90mph....and if i drive 70 ill get up to 19mpg on the hiway....but in all of this its a truck and i knew it would be bad on gas in the first place...

 

No offense but thats just too funny that wheelchair must be souped up or something

 

well, to say that i get 24.6 mpg on the highway might upset some folks, but thats the way it is...'02 s'crew 2wd, 3.55ls, 4.6L...dual exhaust and a k&n filter. my tonneau really helped get another 1.5-3 mpg on the highway.

 

No, actually, I thought it had a flat tire when he swerved in front of me a cut me off

 

You guys are great! My coworkers think I'm crazy when I start laughing at my computer!