Stage 2 help! Losing MPG?

Hi All,

 

Need some help & advice from my LGT owners about Stage 2. Here's the setup:

 

I have an 05' LGT (AT). I recently decided to take the plunge, and upgraded my LGT to Stage 2: Cobb UP, Cobb DP w/ Cat, and Cobb Access Port. A very trusted mechanic of mine (I've used for years) did the installation. I flashed the engine w/ Cobb's Stage 2 "CA 91 octane" map (I live in CA . And, in terms of feel / power / torque, it was awesome! Eliminated a lot of the Turbo Lag, etc. However, after the fun, I decided to do a test on the Fuel Economy on the car, and I'm noticing HUGE losses in Fuel Economy.

 

On a Full Tank, driving *conservatively* (No Hard Revving, No "gunning" the car, etc.):

 

1. Stock (Before Stage 2): I averaged ~310-340 miles on a full tank (w/ AC running).

 

2. Stage 2 (after installation): I'm getting 275 - 290 miles.

 

 

Is this correct?

 

Seems like a rather harsh drop-off for Fuel Economy?

 

Thanks for any help!

... and its usually the foot that makes the difference

i get better fuel economy but i am running 93 maps in the car. i also add torco to the gas and it seems to really help with the response of the car as well as gas consumption.

ECU might be learning. Give it a few more tanks of gas and see where you stand.

Don't stay in BOOST so long

Try using the cruise control on your daily commute, that should give you more consistent result. Also did you switch gas station or need an oil change? I know my stage 1 is very sensitive to different gas station. Don't go by how much you get per tank of gas, go by your MPG as calculated at the pump.

Nope your right on the money. The only way to increase you MPG is to drive downhill both ways with the engine off. Ive seen 25.5 on the freeway once with my wife driving and the cruise on.

 

Ive had STGII for two months now and I ave 20-21mpg. Try using the cruise more

The thing is that stage II maps are tuned for power, not efficiency. If you just put all the stage II parts on, but left the stock map, it wouldn't be as safe, but would likely be more fuel efficient (I am NOT recommending doing this).

 

You could get a map made for economy, but you'd need about 70k miles of driving to break even. I say I take the 1 MPG hit and drive it like it was meant to be driven!

I get 15-16 all city driving my car like a grandma (tdc stage one tune)

 

and when i drive a little aggressive (shifting 3.5-4.5k) see around 14.5.

VTGT, that's horrible! Even stage II driving agressively I can pull out 19... Might want to check that out...

I get 15-16 all city driving my car like a grandma (tdc stage one tune)

 

and when i drive a little aggressive (shifting 3.5-4.5k) see around 14.5.

 

This car and city driving were never ment to be. I lose 3-4 mpg driving in the city. The stop and go is want does it. Watch you trip Computer, ever time you accelerate it drops to 1.5.

I get about 17 driving hard in the city.

 

maybe a little over 200 miles a tank. TDC stg II

i have the auto too, tdc stage 2 same mods as you mentioned +perrin tmic and i average 28mpg on hi-way and 21-22mpg around my town, not that it makes any difference but also aem-cai too. ya gotta sacrifice a little mpgs to have the power, i really think my car is a little more efficient. lol!

i have the auto too, tdc stage 2 same mods as you mentioned +perrin tmic and i average 28mpg on hi-way and 21-22mpg around my town, not that it makes any difference but also aem-cai too. ya gotta sacrifice a little mpgs to have the power, i really think my car is a little more efficient. lol!

Is that the TDC STG II+ map? Did you use the STGII map before the TMIC or did you do it all at once?

Everything I have done, including stage 2, I still average 22.5. Just about what stock was. Stage 1 got me another 1-2 mpg. Stg 2 dropped slightly, maby because my right foot?

VTGT, that's horrible! Even stage II driving agressively I can pull out 19... Might want to check that out...

 

 

It's 100% city so i'm pretty sure its normal. I still need to datalog but i need to buy a serial to usb cable.

If I drive moderately aggressively in traffic or pure city I only get around 16-17 mpg. I've kept my foot out of it on the freeway and gotten over 30 mpg too. It really depends on how you drive the car and conditions in which it is used. Overall, mileage for me is about 21-22 mpg.

 

BTW, legacy_otaku, I replied to your PM.

Hey All,

 

Thanks for the replies so far! To answer some questions:

 

1. I got an oil change just before I had these parts installed.

2. The "290 miles" I got was being *really conservative* (No Lead Foot , No hard gunning, etc.). I was consciously driving nice & easy for that entire tank o' gas.

3. This is only my 2nd tank on Stage 2.

 

So I'll give it a few more runs/tanks of gas and see if it does "level out" or not.

 

What's funny is that I called COBB directly, and their Tech Rep said that w/ my setup, and Cobb's default Stage 2 CA 91 map they believe that my fuel economy should be the same or INCREASE(!), not decrease.

 

But then again, maybe it's just COBB talking marketing speak?

 

From the way everyone's reporting their Stage 2 results, it seems like there is indeed a drop-off of Mileage when you get to Stage 2? Hopefully it evens out a bit more after a bit...

 

Thanks.

I think even with my stomping on it my stage 2 economy has been about the same as 0 and 1.

I get 15-16 all city driving my car like a grandma (tdc stage one tune)

 

and when i drive a little aggressive (shifting 3.5-4.5k) see around 14.5.

 

I was getting numbers like that--and I still average about 260 miles per tank. By the way...I'm STOCK.

 

I don't know if that is normal. A lot of people under the same (or worse) conditions are able to pull a lot more miles out of their gas tanks.

 

I don't drive very aggressively, and I've tried shifting at 2-3K but that doesn't help. I've also used Shell V-Power only for the last 6 months with no real difference. I tried Marathon a few days ago and that seemed to help but not that much. I'm still right around 260-270 miles/tank.

 

Maybe Subaru had a bad batch or something?

+1 don't stay in boost soooooo long..lol

 

u just can't get enough of that...it spools sooner and quicker and so you get addicted to it...I just went stage 2 and I can't wait to get to my car.

+1 don't stay in boost soooooo long..lol

 

u just can't get enough of that...it spools sooner and quicker and so you get addicted to it...I just went stage 2 and I can't wait to get to my car.

Who did it? Cobb or TDC?

I also get about 21-22 mpg with stage 2 (1st tank of gas for stage2)

my gauge says 22.8 after a stage 2 tdc 93 map

before stage 2 it was like 22.5

fwiw i drive the car alot harder now

am i glad 93 is down below 3 bucks a gallon now:lol:

tdc stage 2+map for my mods,added tmic later and got map update from tdc to account for the new tmic.