Hey to all... I have posted a couple of times... a noob here. I just got an 05' STi. Even if I am not driving fast and spooling the turbo a lot, I seem to get pretty low fuel economy, which is expected on these cars. I am wondering if there are any mods or anything that help raise that up a bit... Someone once told me a Cobb kit can bump you up to almost 30mpg? Then again, he might not know what he is talking about. Any feedback would be awesome. -Bo
Coast when going down the hill or better shut the engine when going down the hill. Works pretty well.
you can get close to 30mpg if highway for a long time, esp during long trips. but regular driving...don't count on it.
I believe just at this last fill up I was doing around 16-17 MPG... I have an SPT exhaust and SPT short ram intake---that's really it. I just got it.
haha...yeah... I miss my 2.5 Non-Turbo GT for the mileage..I probably got 25ish. this STi gets a lot of attention. I have had so many people come up to me and ask about it. Tonight at the gas station, some guy in a camaro asked if my car was fast--- he must not know much about the sube's... and another offered to sell me a 20G turbo for $100 bucks...
Stick a piece of wood under the gas pedal so that it won't go to the floor = higher mpg. Both are pretty stupid, and the first one does not work.
haha...funny stuff. yeah I don't drive like a sissy. what kind of sissy would own an STi? anyone have any dirt on an E-85 conversion kit? I had a conversation with a fairly smart guy that did it to his EVO... higher octane, not sure on how the mpg compares or what it does to the car. I hear its safe... ?? I wonder what the E-85 goes for right now at the pump, I haven't even looked.
I know the fuel thing is topic of a lot on controversy... so all politics aside... any thoughts on that?
There is a whole thread on it at NASIOC and, unless I am mistaken, there are some knowledgeable folks on the subject here at MnSubaru, too. Here is the link to NASIOC: http://forums.nasioc.com/forums/showthread.php?t=803341&highlight=e-85
hey, thanks for the link. I will check that out. I found a link as well, and it seems to be one of the EPA approved ones as well. http://www.change2e85.com/servlet/Page?template=Testimonials http://www.change2e85.com/servlet/StoreFront Blurb from site... "Congrats to Johnathan Cipra who won the drawing for a Full Flex for his Subaru WRX STI! Even high powered, turbo charged, ultra performance vehicles like the WRX STI can use the Full Flex and E85"
http://forums.nasioc.com/forums/showthread.php?t=803341&pp=25 Long story short: You need bigger injectors, bigger pump(need to run about 30% more fuel), engine management to run more fuel, after getting it tuned in, you will be paying about the same $ per mile as premium, but getting the advantages of 100+octane fuel. There are other advantages too. I would love to run the stuff, but have sworn off alcohol untill I can get it at my local gas station (nearest station that sells e-85 to me is 40 minutes away). Another alternative would be meth injection... word is you can run a little leaner with it.
You aren't going to get close to 30MPG in the winter. Last fill I was hovering around 16MPG and that's a pretty even mix of city and highway. During the summer it's closer to 19 or so. Not much you can do. The STI is a pig and ethanol doesn't help either.
16MPG? Holy Hannah, is your foot in it all the time? How or why would my 05 LGT currently be getting roughly 22mpg at cobb stage 1 with an AT?
Take that intake off unless you are tuned for it. That could be goofing things up. I can get close to 30mpg, but thats running at 15.5:1 with 48 degrees if timing on the freeway. Standalones ftw.
yea e85 is a bad deal I get 17-18 with my sti in the winter and 19 -20 in the summer. if you drive easy, maybe 1 or 2 more mpg
the intake i have was put on at subaru as it is a factory SPT part. they put it on and did what they needed to do when it was brand new. I met the previous owner--as it was a one owner vehicle. as far as the 05 LGT getting 22--I don't know. Those cars may be tuned better, and they do have a smaller turbo right? I have no idea why such a difference. My foot is not on it all of the time, in fact I have been taking it quite easy for about a week just to experiment. so, basically---what I am getting from all of these messages is that unless all of the stars are aligned, and the moon is purple, that is just the way it is. I am not ripping apart the car or whatever to save a few bucks. I am the proud owner of a mean machine now, so I guess its time to man up and deal with it. Thanks for all of the crazy ideas though!
thats the biggest part to getting good gas mileage, try your best not to go over 65. also just cruisin in the right lane with a fast car looks baddass. and youll save money. thats what i do but then again my gear ratios absolutly suck on my car!
yeah, I have been rolling in the right lane more now...because if I stay in the left, everyone rides my ass expecting me to be going 80 at all times. plus I don't have plates yet and want to avoid the extra attention from the cops. I have no tickets or anything, so I generally don't speed too much. I look at the boost meter sometimes, and it seems that the car actually is getting more boost in 6th gear at like 2200 RPM, than it is in 5th at 3,000 RPM...
to be honist i could not answer that question even being a prior dsm owner...just try your best to keep your boost needle as far deep in the negative psi (vacuum) as possible.
thanks...yeah I figured that would be best---I am just confused how the needle seems to be higher up at lower RPM in higher gears. I wonder what would kill more fuel...the more RPM, or the slight boost that it is getting. HMMM.
16 seems really low. I was getting 18 on my boosted 2.2l w/ a lead foot. There alot of things you can do to increase your fuel economy. It all depends on how far you want to go. Keeping that boost needle as far negative is a big help. alot of people drive with alot more TB deflection than they need. drive slower, anything over 3,000 rpms is wasting gas. accelerate slower and come to stops more slowly. you can draft behind the person in front of you, modifications can lead to improved mileage. getting exhaust or other mods allow for the engine to work more efficiently (noticeable in hp gains). as long as you can control your right foot this can be to your benefit. I think WRX1 who has upgraded turbo and a ton of other mods (AT too) can get 32mpg highway. you might look at getting a lightened or underdrive pulley set. I did an underdrive crank pulley and noticed a 2mpg gain not much but it helps Ethanol will not help you get better mileage. it takes roughly 30% more ethanol to get the same energy as gasoline. Ethanol has a higher octane rating so you can get more power by getting tuned to run it. however you will need to get larger injectors to run this extra 30% more fuel. a new pump may help. but since you are adding more fuel for the same energy means that you mileage will take a hit. on a price basis you will get pretty close to even. it may even be less to run the e85, since its so cheap compared to 92 octane. it looks like all that e85 conversion kit is, is just a mini computer thing which runs the injectors at a higher duty cycle to provide this extra fuel. an EM unit like a cobb AP or utec ect... would allow you to do the same thing and would be way better.
The colder it is the more fuel you use... It's been pretty cold lately. I also cruise around 70 on the freeway to/from work. The tank before this was closer to 17/18. I'd be worried about it but as you can see all the STIs are reporting about the same.
^ yeah. 16 still seems kinda low though. must be playing in the snow too much. I took a little deeper look at that change2e85 website. I would avoid it like the plague. they sell a kit for your "boxter & V4" seriously. if they cant get the engine name right would you trust them with controlling you injectors? for $369 I would buy bigger injectors.
I understand that the intake is a "factory" part. That doesn't get around the fact that people on here have found through datalogging is that intake along with many others have proven to skew how the MAF sensor reads the air, thus causing rich and/or lean spots. Have you had a wideband on the car?
This thread makes me :laugh:. It is all about how efficient everything works together. You car injects gas based off of load, so if you are not working the motor hard (6th gear wot throttle), you won't use alot of gas. Is your car catless yet?? Still running the stock turbo?? Opening up the exhaust will reduce back pressure on the motor and it won't have to work as hard. Mix that with a good tune and finding the motors sweet spot and you can run some serious mileage. I have a 02, with a 18g, txs tbe and all the supporting mods. A moddedm 4eat tranny (Valve body and high stall converter), and I usually run 24-26 in stop and go traffic and 30+ if I can cruise the freeway. The sweet spot for my car is 70-75mph (right below 3k). I am running the most timing at cruiseing rpm and the lightest load. My biggest improvement in mileage was getting rid of the tiny td04 and jumping up the the 18g turbo. The exhaust side is ALOT more efficient. Russ
A full TBE, bigger turbo, and a good tune will help your gas mileage assuming you stay out of boost. Problem is- with those mods it's so much fun to stay in boost that your mpg will likely go down.
The seasonal gas blends seem to always push my MPG down. When it is brutal cold out like recently I make sure to let my car warm up for at least 10min before I get going. Even under 3k RPMs I can almost see the fuel gauge move when I drive the car before it warms up. My 02 with full APS catless 3" exhuast (TBE and UP) with Ecutek tune got 30mpg on the freeway (and droned like a mofo). My 07 with Stg2 (Maddad Stealthback, AP) gets high 20s on the freeway. I suspect an aftermarket axleback and a protune would yield even more. The VF39 swap is soon to happen - hopefully the "bigger turbo" will help a bit.
:squint::squint::raise::raise: I got 17-18 mpg on my last tank. I do almost all short distance (<10 miles) city driving. The cold absolutely obliterates my gas mileage, as the car is usually still warming up when I get to work.
