ssyeller

iTrader: (1)

I get 40 to 45 mpg at 60mph average 28 to 30
Running 321hp with turbo kit.

tiny

this seems pointless, go to 55, reset your DIC, then check it out

Rambotk3

The most i have seen on my car was 409 and that is only with a CAI!

SilvrLT

mine is gettin really poor fuel mileage, im getting 28.9 on the highway at 70mph

glen229

iTrader: (4)

im getting about 32 average

ssyeller

iTrader: (1)

Checking different types of driving. Not drafting or other methods to increase mileage.
Running over 300 miles on 11 gallon fillups.
I do run 80% Freeway driving. Speedlimit 70 mph in my area so that drags it down as well. 70Mph I get on average 33mpg It is the in town that sucks the mileage down right now since I can't keep my foot out of it.

Dunkinuts

I have seen over 400 range if I can keep my starts slow.

glen229

iTrader: (4)

same here but thats hard

Eng@RebelAutoWorxs

glad you like the other bonus' of the turbo kit

mtbrent

Interesting topic. I just did the 2.4 supercharger install, with 42lb injectors, 2 weeks ago. On my 3 hour drive home through WVA, MD, and PA I got 41.1 mpg on the DIC for the trip home. The drive there with no supercharger netted 30.9 mpg on the DIC. I thought damn this is sweet...until I calculated mileage manually. Turns out my trip home got me just over 31 mpg in reality. At full tank, fuel range shows mid 450's though, which I know isnt true. Point of the story is, and I'm no expert but, I believe the DIC calculates mpg based on percentage of injector useage, and doesnt take into account the size of the injectors. So anyone that installs larger injectors could see a false reading for mpg on their DIC if the injector duty cycle is much different than stock. Mine being a daily driven, basically stock 2.4 w/ m62, 42lb'ers and a conservative tune gives me a pretty low IDC. The pcm sees just the percentage, not the actual amount of fuel passing through. This percentage, I'm sure, is just thrown into an algorithm based on the stock injector size. Thus the crazy mpg readings.

So if my theory is true, when installing larger injectors:
New IDC<stock IDC=High mpg reading on DIC
New IDC>stock IDC=Low mpg reading on DIC

The only way to really know mpg is the good old fashioned way of filling up your tank to the top, driving x amount of miles, then filling up your tank again to see how many gallons you used. Mileage/gal used=mpg

Anyone know if my theory is true???

ssyeller

iTrader: (1)

I have been looking for just that information but could not find anybody that new how the mpg was actually being caluculated. I have ran full tanks through but never a 100% freeway run to see if I could get a real calculation for freeway MPG. I have gotton over 300 miles per tank when I have ran a larger percentage of Freeway.
Still getting great mileage either way but would like to know exactly how it is calculated.
I am running 60# injectors.

dragon_slayer

what can be the problem, i've got a 2007 cobalt ss/sc stock..i was getting 36mpg and 470ish on a tank of gas, now i'm down to like 32 mpg. thought the aif filter may be dirty, and it was so i got an OE K nd N and now it runs better but no improvement, the tires have the correct psi, but what elso could be causing a drop in mpg all of a sudden.

usually to work and back i drive 55 to 60 w/o using the AC. what else can i check to figure out my my gas mileage is sucking. work is a 115 mile round trip everyday.
thanks

ssyeller

iTrader: (1)

I am on a freeway that is 70mph. What I noticed is that before the turbo I would get 36 mpg at 60 but as soon as I went to 70 plus it dropped to 32 or so. I would say check your mph verses mpg. If that doesn't make sense then will have to look else where.

dragon_slayer

i set the cruise at 55, which is what i was driving before, now at 55 it gets no better than 32 to 33. and i havn't changed anything except the oil, and the air filter

Snakes709

most i ever seen on my car was 666km (7.7L/100km)....after seeing that number after i left the gas station i had a bad feeling about driving home...lol

NotME

^^^lol, thats funny most i seen is 441 miles getting 33mpg

Omega_5

My best was on a on the way back from my girlfriends parents place. A full half hour stretch with the DIC reading 4.6L/100km (51 MPG). And I verified it with a fill up too!

07cobalt4life

my dic said 500 out of a tank getting 41mpg

ssyeller

iTrader: (1)

The gauge is incorrect on mine all the time. It would be nice if a real chevy tech could give us exactly what is up with the calculation.

Omega_5

Stock injectors, as well as 42's won't affect the DIC readout (usually).

60lb/hr injectors can, however, affect the DIC depending on how your car was tuned to use them.
Reason being that the flow rate modifier can affect how the DIC reads injector flow.

SSdan

I get like 230-240 miles out of a tank. Mostly city driving. Makes me sad

Rodimus_Prime

iTrader: (3)

wtf pure highway driving 70-80mph using cruise control best I ever got was 336 miles and lights were blinking all over it was low

ssyeller

iTrader: (1)

Point of interest 60mph seemed to be the sweet spot for best mpg. That will alone increase the mpg by 3 to 5 mpg at least for me. Also if I go south it is more down hill which will also increase my mpg. Actual mpg is about 28 mpg in normal but can get 30mpg if I am really trying.

06SS ALL DAY

30 mpg here at 65 cruise control with 42 injectors 3.1 pulley, plugs, drop in oem k&n filter

j.ho7

Well up here in Canada in the summer i got about 600-650kms to a tank highway and 550-650 kms in city/town driving. winter it's more like 400-500kms because of all the idling and warming up i have to get it to do, less traction on the road, and harder to keep tires pressure at right pressures... :P