Hello all...
I just got my stage2 and Gmpp exhaust installed THursday. Im liking them both very much.. SO.. I drive aprox 100Miles each day 50 miles back n forth to work. I got gas today,reset the MPG estimater. and was driving between 65-85. I look down as I get to my exit and I see 39.3MPG... ummm how wrong is this?
Im thinking the MPG should go down from this? I could be wrong...
any input would be great.. thanks guys..

 

I've heard this before, with my GMPP exhaust i get about 34 so Stg. 2 might get you a little higher

 

How the hell are you guys geting such good mpg?

 

stage II will be worse on gas.. not better.

calculate exactly how much mileage you get on a full tank, and how many litres/gallons you put back in to fill it up. then calculate your MPG

 

Hmm thats sweet... I was thinking just the opposite.. guess thats what I get for thinking

 

No, it does get slightly better gas mileage because the all around better efficiency of the engine makes it easier for the engine to reach and maintain a set speed. On the other hand, you can get worse mpg with stage II if you tend to "give it a little gas" more often than you did before you got it installed.

 

stage 2 give you BIGGER injectors therefore MORE fuel will be dumped into your car , therefore you will get LESS miles per gallon

 

thats what I was thinking... easy guys... no need for an argument here.....just wonderin if my calibration is off..

 

The amount of fuel with bigger injectors is more of a factor then increasing the power aka making the car easier to keep at a certain speed. Either way the motor is getting more fuel and using more. Locigaly you should get a little worse. Mine dropped about 2mpg avg. When I get on it, forget mpg peroid. I roll around with about 26mpg. Thats city, town, and country driving all together.

 

i've noticed better gas mileage with stage 2 on the highway as well, i think the smaller pulley is providing a little bit more efficiency as long as you're not flooring it, and staying out of boost.. the on the highway with cruise control set at 70mph i get no less than 32mpg, typically a couple mpg more. but getting 39mpg above 70mph is insanely good, maybe its slightly downhill the whole way to the exit.

 

Bigger injectors does not necessarily mean more fuel, it's just the capability for more fuel. Those injectors come with stage 1 as well, as as long as you don't use that extra 500 rpm at the top, you're going to get the same mileage you did before. Highway mileage with stage 2 will be almost identical to stage 1, city mileage will drop.

To the guy getting 39.3 on the DIC, I have noticed that it tends to be a little generous with it's readings...mine consistently reads 1-1.5 mpg over what I'm actually getting. Best bet is to reset one of your trip meters when you fill up, then when you're empty again, check the miles against the gallons you put in. FWIW, I do mostly city driving, and get about 290-300 miles on 12 gallons of gas. Stage 2 w/2.8.

 

my ride home has a few up and down hill parts. but I do try to stay out of Boost. I noticed difference in GAS too... Shell 93 I was getting approx 275 to the tank.. now with BP 93 I can squeeze out 335-340. thats from full to filling up with about 11.5 gallons. Now THATS insane.

 

Wow, seriously? What are all the caps for? For you to emphasize the fact that you're wrong? I've seen you make quite a few posts where you try to be all hard, but you end up being wrong quite often. If you cruise and are light on the gas you will not necessarily use any more gas than before; it's called INJECTOR PULSE WIDTH.

I will agree here. If you get on it you will definately lose mpg greatly. However, even though the larger injectors and the tune which is more rich use more fuel, your engine makes more power across the entire rpm range. This, at least on the highway while reaching cruise speeds and maintaining them, will keep your gas mileage around the same. My friend gained 2 mpg average with his Stage II on his RL; he doesn't get on it any more or less than he did before. Plus, I've seen alot of people say that they experience slight increases in gas mileage.

Edit: You're right though, it has nothing to do with the pulley as at cruise you are off boost. I've heard very contradictory things about the stage II tune, so I won't say either way, but I know for a fact if you get a custom tune on top of stage II you could tune for more gas mileage reguardless of the larger injectors etc. I've done it before.

 

^ I agree. Wish it was highway driving to get to work from where I live. Its a decent road straight to work. Speed limit of 55 mph. I have to drive through a little bit of the city to get there though. Anyways, I envy those who are getting 30mpg+. My beater car gets 37-42mpg. 89 Geo Spectrum baby! Maybe I need to clean my CAI filter and replace fuel filter.

 

The Geo is where it's at .

 

i didnt bother to read everything so forgive me if someone else already pointed this out but... a big part of stage one and stage two is the tune, now alot of what the tune does is reducing the fuel and increasing the air in the mix (because the car is set very fuel rich from the factory) so you can increase the air to the mix, get more hp because you did so and still get better mpg because you are REDUCING the amount of fuel to the air/fuel mix. at least thats how it was explained to me.

make sense to anyone else?

 

This was the last push that I needed to order the Stage 2 kit. I've been really worried that my fuel economy would drop like a rock. If people are getting near the same that's good enough for me. If it gets better with conservative driving all the better.

 

They are in fact bigger injectors but as long as you stay off the gas they don't have to work as hard to give the same amount of gas.

 

I don't want my previous post to imply that stage II is some miracle as far as mpg goes. The only point I was trying to make is that it will not hurt your gas mileage like it may seem (Unless you constantly get on the gas). Anytime you increase performance by increasing the actual burn efficiency (such as timing advance, better AFR etc.) you get more power out of the burn in the cylinder. This in turn means that the engine can more easily produce it's power. With stage II alone, you may notice a slight decrease in mpg, increase in mpg, or it will stay about the same depending on how you drive it because nothing too radical is changed with it (If you drive it hard and create more boost much more fuel will be used because there will be more airflow). However, it is possible through tuning to increase your mpg by increasing burn efficiency.

 

thanks everyone for adding your bits of info.