Take the Lead shoe off your right foot, lol no but really the only thing i can think off hand is to check or clean your air filter.

 

iv only had it on since june...im stumped. it is winter and it has been bad the last couple weeks but still...do you seriusly think it should be so bad? maybe im just being unreasunable?

 

My gas milage has always been horrible in the City. I have a 2007 3.7 AT Ext cab(also with 3.73) I hardly ever get above 13-15mpg during the summer, it has definately gotten worse. I drive it very easily, never really going over 2500rpms and coast best i can before lights. I have a AEM filter Tune and MBRP. I run ONLY Premium through it. Im never anywhere close to that 17MPG they say i should get.

 

not trying to say anything, but are you guys figuring right. also do you have stock tires, if NO, have you had the speedo calibrated for the tires. with intake, exhaust and tune, you should be around 17 at the worst.

how is it running????????

what have you done to it lately, tune up, anything?????

 

stock 18 inch eagle rsa's, its only got 14353 miles on it. oil changed 1,000 miles ago. no it hasnt been tuned, but isnt an intake suposed to improve not drop milage?

 

ok, not the tire size. why do you let it warm up for so long?????

 

10 to 15 min in the am when its about 3 degreese out, 10 minits after work, i hate being cold

 

I have 18's as well the stock Xtremes. It was re tuned for these tires and it def seems to read miles better as the speedo now matches the GPS unit! it was off by 5mph with the stocks and stock pcm and 65...shitty GM...I calculate my mileage by taking the amount of miles driven on a tank say 220 miles and fill up around 16.5 gallons(about when the light comes on so not a FULL tank) 220 / 16.5 = 13.33 mpg. and 220 is on a good cool(not cold day) I usually run 50 miles per quarter. I know mine has dropped since winter as i only let it sit maybe 5 mins sometimes less before work(I drive 2 miles to work) but the above mpg was what i was regularly getting back last summer.

My Highway mileage is MUCH better tho. I can put on 100+ miles per quarter tank when just highway with the cruise at 62mph with nothing in the bed. 400 / 18.0 = 22.2. I think the best ive done is 26 mpg on a short road trip.

Ive always had horrible millage in the city, dealer dosent want to hear anything( theres only ever a problem that will affect mileage if the CEL is on..blah blah blah...It makes me want to just leave a massive burnout line down the service bay)

Kinda wish i could do something about it tho...13 or - mpg is pretty harsh.

 

The lowest ive recorded was 11.2 mpg...that was right when gas hit 4$ a gallon too...i was inches from tradin it away.

 

I have a crewcab 3.5 4wd Z71. Mileage always sucks in the winter I go from 270miles/tank summer to 220miles/tank in winter also warming up the truck doesnt help. I let engine warm up 2-5 min in morning. And truck is fairly warm in 1 mile.

 

Warming up AKA not moving = 0 MPG. You are killing your MPG with the extended warm ups. Have seat heat? Only takes a minute to warm up. I know you hate the cold but try doing 1 minute warm ups for a tank to see what that does for you. Take it easy on the truck till it gets up to standard operating temps.

 

I would say the same on the warm up, but with a tune, you should be getting, very good milage.

 

The winter gas formula sucks for mileage compounded by your extra long warm ups. I don't even track mileage in the winter because it's never an accurate reading because of it.

 

All ive been saying was my recorded for summer mileage. Ive stopped recording mileage as well since i know it has dropped even more. I rarely have time to actually let it warm up, as the light 1/4 mile from my house has like a 3 min wait if i dont catch it(I never do as i leave at the same time every morning) so it gets warmed up at that light. My mileage at a glance cant be any better than 11-12 mpg. I think its just my part of the city, ALOT of stop lights and none of them are synced right...

 

My 09 V8 2wd has gotten 17.5+ the last 3 tanks full, mixed city/highway.
But here there are no hills, so the rpms are pretty steady.
Except leaving lights, where I am a lead foot, as I feel, if you are the first at a light it is your responsibility to get the heck up to the speed limit and don't dictate/limit the speed of everyone behind you. I also don't like being crowded

 

I let my truck warm up for about a minute in the mornings, that's it. Hate the cold? Get a hat and gloves.

Your intake/exhaust are having an effect also. Like to hear 'em when you take off, go through tunnels, etc.?

 

Yeah I get good gas mileage I'm running 30inch tires but i guess its thanks to the Tune (PCMforless) In the city I get 17-18MPG and on highway around 19-24MPG so I'm happy, maybe you should get tuned.

 

Let's see here, You are telling us that with a full tank you can only drive 150 miles? ( 8 miles to the gallon with a 19 gallon gas tank) That is really bad. Even with warming it up. But 15 mins warm up is a little long, don't you think? Are you sure you are figuring this right? Not trying to insult you. My worst mileage is 16 miles to the gal with a 3.7 liter.

 

:roll: Warming it up is the problem. Our trucks take FOREVER to warm up if you aren't driving them. Just get in and go. Keep the rpms below 1500 and you'll be fine. My truck warms up in 2 minutes when driving.




Not to mention that you are potentially killing your transmission. Warm engine means full power on a cold drivetrain. Not the greatest idea.

 

i noticed that on my 08..letting it sit and warm up it takes forever 10min or so...but if u start it and drive it it warms up alot quicker and does save ur milage i been getting around 300miles a tank

 

My truck gets a 2 to 5 minute warm up before I leave home for work and work for home and that's just get things moving around. The heater actually starts to kick out heat about a mile or two down the highway. Does it suck? yes, but the only way to warm up the truck is start it, let it set while I brush it off and then put it in gear. I have to agree with most, you're wasting gas with that 15 to 20 minute warm up time. Give it a minute or two and then start off nice and slow and your milage will improve.

 

Winter gas may have a little to do with it but the warming it up thing will make ur gas milage reading incorrect because you are burning fuel without logging miles. These trucks burn a surprising amount of gas at idle.

 

thanks for all the info, im glad im not the only 1 to have it that low, yes 15 min warm up is exsessive. i am trying the 2-5 min warm up this week, i just filled the tank the otherday. im hopeing to have it tuned buy spring

 

i noticed that on my 08..letting it sit and warm up it takes forever 10min or so...but if u start it and drive it it warms up alot quicker and does save ur milage i been getting around 300miles a tank

Right. I fill my tank about every 275 to 300 miles and I'm below 1/8 of a tank left and it is usually about 15 to 16 gallons. That's about 18 to 20 miles a gallon.

 

Well first off i know "I" am talking about ONLY city Milage. As there are to people confirming horrible milage. As i stated before I keep RPMS below 2500 and am light on the throttle. Intake/Exhuast/Tune and still approx 11-14 mpg CITY. Only running Premium. and this mileage is my results of the summer months, NOT WINTER- No Warm Up- Not Winter Fuel(My winter mileage has barley changed if at all. still about 50mi per 1/4 tank) and i realize that your "is your math right" comment is towards 8mpg but as ive shown before 220/16.5=13.33 which is sometimes ABOVE avg for my truck. I dont know what else i could be doing to help it out(I think its just the excessive amount of stop lights)