LS4 Performance - DOD SS 14.9 mpg- Silverado 15mpg

After 3000 miles on the SS it's getting 14.9mpg, about same milage on my 06 Silverado Extended Cab 4x4 with 310hp 5.3 it's getting15mpg. I didn't buy this car for gas milage, but you would think it would do way better than a HEAVY 4x4 without DOD.

heavy foot or speeding or all city driving.

Mine avgs about 24 mpg and 350 miles to a tank if im nice to it and do 90% highway other wise its about 21 with mixed and some beating. 2900 miles.

Probably a heavy foot. I run 16-18 around town at the very least. I usually average around 20-21.

reset the average economy, it will go up.

Yea it is mostly city miles,and I'am sure DOD would have a bigger effect on the highway. Heavy foot, well my wife drives it 90% of the time guess I'll have to have a talk with that woman.

I'm averaging about 18 in town, and about 24 highway.

Same here....18 city 24 to 25 hwy...

It doesn't matter how many miles per gallon your SS gets. What matters is how many races won per races attempted.

Yea it is mostly city miles,and I'am sure DOD would have a bigger effect on the highway. Heavy foot, well my wife drives it 90% of the time guess I'll have to have a talk with that woman.
haha if she is like my wife you might want to check the brakes around 14,000 to.LOL :eek2:

wow i would figure with DOD you guys would get alot better milage then that...with me cammed ls1 and big ass injectors running 400 at the rear wheels with 4.11s...i still get over 20mpg on the highway...more like 23

new car manager's Imp. SS demo is averaging around 32mpg with about 65% being freeway

Just took my MC SS on a trip of 1000 mi, high desert and mountains, and averaged 23.4 mpg, with the A/C on most of the time- not too bad considering the car only had 950 mi at the start of the trip.

wow i would figure with DOD you guys would get alot better milage then that...with me cammed ls1 and big ass injectors running 400 at the rear wheels with 4.11s...i still get over 20mpg on the highway...more like 23

Yeah i was really hoping to get a better gas mileage with my new 06 monte ss then my 98z. I go as lightly as possible on the car and city i can average like 13-15 my Z can get like 16-19 on high way my Z gets like 27 my monte gets like 23. But hopefully since i only put like 320 miles on it since i got it had 80 miles when i brought hopefully as engine breaks in should get better mpg.

new car manager's Imp. SS demo is averaging around 32mpg with about 65% being freeway

Gonna have to call BS on this one. There's no way this engine is "averaging" 32mpg with 1/3 of it city driving.

Gonna have to call BS on this one. There's no way this engine is "averaging" 32mpg with 1/3 of it city driving.

yeah, no way he's gettin' 32...

i've got 15K on my Monte SS, and with 50/50 city/highway, I'm getting about 20/21.

yeah, no way he's gettin' 32...

i've got 15K on my Monte SS, and with 50/50 city/highway, I'm getting about 20/21.

I can't break 12s, believe it or not. I drive primarily in the city and have a heavy foot and am consistently at 11.5-11.7mpg at the end of a tankful. It's been that way since i got her in Sept. At first i thought something was wrong, but my highway mileage is fine. When i can get on the highway, i'm pushing 80mph and seeing about 16-18 when cruising. If i sit back with traffic at 65, it's closer to 23mpg, and if i do the speed limit of 55 it climbs to near 28.

[EDIT: While cruising at 80 i get 21-23. IT's accellerating from 50 to 80 when i see the 16-18. I just checked this AM commute]

However, rarely do i attempt to accelerate so hard that i break the tires loose, so i don't think i'm THAT hard on her, either.

I can't break 12s, believe it or not. I drive primarily in the city and have a heavy foot and am consistently at 11.5-11.7mpg at the end of a tankful. It's been that way since i got her in Sept. At first i thought something was wrong, but my highway mileage is fine. When i can get on the highway, i'm pushing 80mph and seeing about 16-18 when cruising. If i sit back with traffic at 65, it's closer to 23mpg, and if i do the speed limit of 55 it climbs to near 28.

However, rarely do i attempt to accelerate so hard that i break the tires loose, so i don't think i'm THAT hard on her, either.

Highway is right, epa city does not take into account how long you spend sitting in traffic. What were you getting from you last vehicle?

that car sucks gas like a b*tch! when they came out, i thought, "cool a v8 fwd chevy car, maybe it'll get over 30mpg too on the hwy w/ dod" but hell, 22-24 hwy? i know some trucks that get that..

Quote:
Originally Posted by Mike00FRC
Maybe we'll get lucky enough to see a merging of the Emo + ricer cultures... Bunch of slack-jawed faggots who want to slit their wrists everytime they get crushed by a domestic.


Holy shit thats a sig

Highway is right, epa city does not take into account how long you spend sitting in traffic. What were you getting from you last vehicle?

I had a 96 Explorer v6 that i was getting 12 in....all the time fixing little chit thinking something was seriously wrong. I spent the last 2 years with that thing messing with all sorts of "defective" emissions equip. only to find that b/c i live, work and play in the city, racing from one light/stopsign to another, i got 12mpg.


And yeah, that one helluva sig :jest:

On a few other posts, I've been complaining about my car not getting the advertised 28 mpg highway, and no real gas mileage gains on my car with the DoD.

Wanted to report that I took a 700ish mile trip through Chicago and into Wisconsin the past couple of days, where the speed limit is 65. I kept my car at 69 in cruise. My DIC was reporting 23 - 34 mph / instantaneous. Lotsa long interval 4 cyl mode too. Car went from 20.0 to 20.1 average mileage / 9K miles (I reset that function the day I buy a vehicle, and never reset it to see the vehicle's lifetime average).

The MCSS must hit areo-drag at 70+ mph, as I set my cruise at 74 for all of my highway driving and get 22 - 23 mph. EPA highway mpg must have based off 65 mph???

BTW - had allot of fun playing tag with a BMW M5 on the I-90 in Chicago.

My GXP has avg over 19mpg around town. When I first got it, it avg about 17 around town. Only a few things have changed in that time. It has gotten cooler, the car has more miles on it (more broken in ~6k mi), and I changed the oil to Mobil 1 5W-30. Oh also my lighter-footed wife has driven it more. :emb:

Its true, my 06 SS is getting about 15 in the city. And I drive city about 90% of the time so that sucks.. I have a light foot and still get shibby mileage. Not good...

I can't break 12s, believe it or not. I drive primarily in the city and have a heavy foot and am consistently at 11.5-11.7mpg at the end of a tankful. It's been that way since i got her in Sept. At first i thought something was wrong, but my highway mileage is fine. When i can get on the highway, i'm pushing 80mph and seeing about 16-18 when cruising. If i sit back with traffic at 65, it's closer to 23mpg, and if i do the speed limit of 55 it climbs to near 28.

[EDIT: While cruising at 80 i get 21-23. IT's accellerating from 50 to 80 when i see the 16-18. I just checked this AM commute]

However, rarely do i attempt to accelerate so hard that i break the tires loose, so i don't think i'm THAT hard on her, either.


Man I've read about your MPG issues on just about every board. I woulda thought by now that you would have seen better results as the motor broke it. Dang. At worst, I'm getting 14 mpg BANGING it around town. Normally I get between 16-18 in my high traffic town with lots of lights.

And 32...I could see 32mpg if it were pure highway miles going like 50-60. So I call a BS on that too.

no real gas mileage gains on my car with the DoD.

I get about 2-3, maybe 4, mpg increase when dod kicks in. Here is how to test it.

First of all, normally, the computer won't let it go into dod at speeds past 80. But I found a trick that if you take it up to that speed. Set cruise control and then click down ONCE, it'll kick in dod. I've found this works at speeds as high as 90-95. I haven't test beyond that in lieu of being afraid to get caught speeding.

So, take your car up to 80-85. And hit cruise control. Note the instantaneous mpg (make sure you're on a nice flat road). Then click down once and when dod kicks in, note the change in mpg.

Yeah, my mileage still sucks. I'll be the first to admit that i get on her quite often, but i can't imagine the rest of you don't as well. It comes down to the fact that i cannot coast/cruise for miles at a time like most of you can.

It's good to see another member with similar issues (Tony_SS). I bet i could get 13-14mpg combined if i stayed off the pedal, but what's the fun in that?

I've got a laundry list of problems to see the dealer about. Mileage will be at the top of the list. Unfortunately, that means i need to temporarily remove the K&N so that they don't give me sh!t about it...

I actually hit a lot of traffic and we have a ton of lights. I still dont see how you're getting that low man. =P Good luck at the dealer.

I get about 2-3, maybe 4, mpg increase when dod kicks in. Here is how to test it.

I'll try the "down" trick tonight on the highway.

I see the 2 mpg on my car on average as well when the DoD kicks in. To me it's not worth the $$$ we paid for it on the vehicle, I figure we will pay for it after 100K miles, maybe, if it doesn't break 10K out of warranty.

On the overall gas milage, my '98 Regal GS (supercharged w/ 3.4" pulley) averaged 24.5 mpg / 45K miles, and my '03 Impala w/ 3800 (non-SC) averaged about the same. The 3800's would hold +30 mpg / highway consistently. The MCSS averages 20.1, all vehicles are at least 90% highway, 10% city with heavy shoes.

I guess my point would be that a "4 cyl" should be able to do allot better, all things equal.

try reseting your average mpg and see what it does, i bet it goes up

i am getting 20-21 85% city. but i am really trying to get good MPG.. when i get my foot into it that number goes down a bit. be sure to reset your MPG meter every tank also.

Update, I havent reseted the milage once. it shows 15.6.. and thats 90% city. plus, I have some fun with it.. so it's not that bad I guess.

wierd i tell ya.
im not where near stock, i average 22 in the city, and 30 on the highway. got me, then again, i really don't beat on the car during the week. i do however, beat the holy fuck out of it on weekends. the mileage really doesn't change

reset every time you fill er up..!!

actually i don't, i rarely do it honestly, if i did that, id be averaging 25 in the city, and 38 something on the highway

wierd i tell ya.
im not where near stock, i average 22 in the city, and 30 on the highway. got me, then again, i really don't beat on the car during the week. i do however, beat the holy fuck out of it on weekends. the mileage really doesn't change

Yeah - I talked w/ a GXP owner a couple weeks ago, said about the same. His car averaged 27 mpg.

I don't ever reset the fuel average on any vehicle, so I get the "lifetime average". Now up to 20.2 from another trip.

The DIC's calculation is based off amount of fuel used -vs- miles driven (I don't know if this car uses readings off the fuel rail or estimates off the float in the tank), so if you drive nice during the week and don't use "gallons" of gas on the weekend, you won't adversely affect the overall G/M.

Getting a tune must help a lot. I just got and installed my CAI today. My first real mod on this car (other than the MP3 update to my Nav system). I hear my mileage should increase a bit just from that. Won't for a little bit though, cause it sounds too cool :D)

(I don't know if this car uses readings off the fuel rail or estimates off the float in the tank),.

Little bit of trivia...the computer figures gallons in the tank, and is pretty darn accurate too. I was scanning the car before and after fill up and sure enough the pump and the PCM matched. But then again, my old '03 Monte was off by some 3 gallons with that version of trip computer (it actually showed gallons on the dash display), so YMMV unless the new ones are all more accurate than before.

(I don't know if this car uses readings off the fuel rail or estimates off the float in the tank)

Historically, an FI car knows how much fuel it's using for the mpg readout, by calculating injector open time at the fuel pressure it knows it's running (or at least, thinks it's running), times a programmed in constant for how much fuel that actually equates to...

That's the reason people think they're getting better mileage when they do an injector cleaning, because the injectors slow down a bit after they start to get microscopic debris in them that builds up over time, and the O2 sensor sees that, and adjusts the long term fuel trim accordingly, then they clean the injectors, and all of a sudden the display says the're getting better mileage, because the injector pulse width has shortened, because the injectors flow better than they did when they were dirty...

The other question is: those who are getting horrible mileage, have you actually done the calculator thing with how many miles you've driven, vs. how much fuel actually goes into the tank, and done it over an extended period of time? If the fuel pressure is a bit low, the injector pulse width will be longer, and the display will read crazy low, because it thinks it's dumping more fuel than it is... This is if they aren't reading the fuel pressure, which I don't know if they are or not on this engine...

Mike

Getting a tune must help a lot. I just got and installed my CAI today. My first real mod on this car (other than the MP3 update to my Nav system). I hear my mileage should increase a bit just from that. Won't for a little bit though, cause it sounds too cool :D)


id suggest you stick a wideband on that sucker. you might be sucking down more gas then you think through out the rpm range.

i have yet to see a cai that doesn't make it run rich

Most likely I am running rich. I definitely need to get a tune. HP Tuners kinda scares me (cause I suspect I will F' something up).

I am going to order Jimmy C's downpipe and get my exhaust done (hopefully in the next couple of weeks if my bonus comes through).

Then I guess I will see about getting a vector tune or something (I am guessing I have to shell out $400 every time I upgrade something, so I kind of want to do the exhaust first).

I am kind of wondering if I should do a shift kit as well (if they are even available for our cars) before getting the PCM.

:confused:

Good idea on the pump calc, never tried it, maybe putting too much faith in the electronics.

I'm going to go by the dealer and see if they can update any of the software as well, since I think I have an early production model (my engine cover says DoD).

if you do a westers tune, you will most likely get the tune that is in my car right now {which is very good btw} and it has a lifetime free update deal with it too.
i have no problems with vector, good guys, still learning like the rest of us. but the customer service of westers/tunetime is second to none. {my opinion, take it as you will}

id post the address, but the ls1tech nazi's will get me for them not being a sponser

Finally got around to doing a pump calc - hit 24.3 average mpg. I can live with that!

Lifetime average up to 20.3 as of this posting.

Just took a 700 mile trip over thanksgiving, averaged 24.7 mpg at 80mph average on the interstate, can't complain one bit!!!

Yeah - my pump calcs are all averageing in the 24's, which puts it the same league as my S/C 3800's.

Wish my DIC didn't say 20.3 mpg / lifetime.