my '03 gets 13-15 city 19 hwy (65 max MPH). Bed cover on it drops to 13/15. Cover looks nice but it helps eat up some more gas. Bone stock truck of course, no mods other than a pair of Hankook tires on the front and the stock GY's on back (new when I got the truck). I did notice that the mpg improved with the Hankooks compared to 4 GY's. Going to get another pair of 'kooks soon as the GY's are almost gone at 16,000 miles (truck has 62,000 on it now). Something else that made a difference in mileage was something that I had posted a week or so ago about a ring of carbon built up behind the TB butterflies. Cleaned that out and MPG improved about 2. Keeping RPM as close to 2000 as possible helps my truck it seems. I usually keep it around 65 mph on the highways. No need to waste a bunch of fuel to get there 30 seconds faster, IMO. I don't drive hard, if you can't tell. I have drag cars if I want to go beat on something...but don't get me wrong, I'm not afraid to line 'em up in the Lightning against a Hemi (or chevy, Mustang, whatever) & hand him his ***. I am still amazed on how well the Lightnings do everything. Handles good, pull trailers, haul stuff around, and still a lot of fun to drive. I use mine for all of the above...and I will pull the race cars to the strip from time to time as well. After all, it's a truck!

 

I do have a bed cover on my truck. I also cleaned my throttle body the other day. I had a p1131 code on my truck when I bought it, so I don't know how long the guy drove it like that. I went ahead and changed the o2 sensor, but my mpg are still about the same. If the guy drove it like this for a while could that have fouled the plugs up?

 

I drive it like I love it, and it averages 11-13, usually at 12mpg... mines a 2000 Tuned, longtubes+exhaust, CAI, 4lb

 

Gotta pay to play.

 

I've been getting 11 MPG. May not be anything wrong with your truck.

Mods are below, my truck is in the 435-445 RWHP range.

 

you may have an abundant amount of oil in the inatke tract &/or a clogged intercooler

just my $.02

 

I drive mine like I stole it! 10.5 to 12 mpg. you will lose about 10% mpg with oxygenated fuel.

 

Certified Drunk, tell me more about that.

Only on the last couple tanks, with no changes made to the truck, I was for no apparent reason getting an extra 2 MPG. I was wondering if the gas was different. Is the oxygenated gas a seasonal thing? I would think oxygenated would increase, as opposed to decrease MPG?

 

I haven't run the pcv delete system yet and I do notice some oil in the throttle body. So the oil mixing with the gas will cause poor gas mileage? Also how hard is it to clean your intercooler? thanks

 

Took my L to Pensacola, FL. from Tampa, FL and averaged 17 mpg cruising at 80-85 all the way up there. Loaded up all my Daughters belonging, in the truck bed and a 4x8 trailer and cruised at 80mph all the way back to Tampa and got 13.5mpg. I have a portedS/c, Ported plenum, 4#lower, 2.8 upper, Headers,high flow mids and magnaflow cat-back, plus a real good tune. Puts out 426 rwhp. Very happy with what I get. My around town is usually 12-13, depending on what shoes I' m wearing. Light or heavy.

 

my 2000 got 13 - 16
my 2004 gets even better

 

I'm with you on the 2000L - no mods at all and driving (mostly!) like a nun and I'm averaging about 280miles per tank

while I accept that there is a penalty to be paid for weight and performance this is a bit harsh!! lol

 

Yeah and UK gas prices suck harder than a Brooklyn Hooker

 

ain't that the truth!! Mind you I nearly boobed on new years - stopped off to refuel and pressed a little button to accept the price of fuel.... then thought "that's a little weird" and rechecked it - roughly $9 per US gallon mind you once I'd recovered I realised it was 102 octane still not enough interest for me to buy it but explained a lot

 

I average 15 mpg, and I drive like an as shole