How I increased my gas mileage

[idosubaru]

"How to increase gas mileage"

get a car that gets good gas mileage. making a car that gets bad gas mileage get good gas mileage is no easy task. there are good EA82 and EJ22 vehicles that get 35-40 mpg. and they can be had on the cheap. my insurance went down when i added a vehicle, multi-car discount. cheaper to have two vehicles per person. or swap in a transmission that has better gearing. mileage varies wildly across the same motor EA82's or EJ22's, but the trans makes a huge difference.

[Slegacy96]

Im a student, I cant afford to buy another car. The point of my thread here was to show how I got a 32 mpg out of an engine only rated for 27 mpg and still have good horsepower and of course, not drive like grandma.

 

 

So instead of buying a car that gets good gas milage, I made my car get good gas mileage. It justs makes more sense to me.

[idosubaru]

i was posting a general answer to previous poster (not you).

 

i've had good luck playing with the intake and exhaust and getting additonal mpg gains on highway driving. exhaust mods only helped on older generation subaru's, haven't tried it on newer generation yet.

 

i also agree driving like grandma is not an option for me!

[Slegacy96]

I see. I wonder if I did drive like Grandma (who has a '99 Cirrus with 18,000 miles) what k ind of milage i would get.

[subeman90]

my grandma would spin the tires on her 71 sedan de ville at almost every stop sign....don't drive like her she was way cool for a grandma:D

[fnlyfnd]

haha, I knew someone who had a grandma like that. I was scared when I rode in the car with her.

[Lawsonmh15]

Ok well I see youe drag argument and I raise you 2 mpg. I too questioned the aerodynamic effect of wind blowing into the hood but I have benefitted from it.

 

What are you doing to keep water and debris out of the intake? Or did you not mod the intake to meet the scoop? If not... What was the point in removing the bottom of the scoop? Allow water to drip on FPR's and Coil pack???

[scorch]

Im a student, I cant afford to buy another car. The point of my thread here was to show how I got a 32 mpg out of an engine only rated for 27 mpg and still have good horsepower and of course, not drive like grandma.

 

So instead of buying a car that gets good gas milage, I made my car get good gas mileage. It justs makes more sense to me.

 

But you are not using your students' critical reasoning skills (do students ever even have those anyway these days?) if you think your scoop mod and fuel treatment are responsible for the difference. If I have a cold and I eat pizza and my cold eventually goes away, that doesn't mean that pizza cures the common cold.

 

I can relate to your desire to get the highest MPG possible, but there are better things that you can do to get there than the two things that you mentioned.

[scorch]

It is hard to really know you have made progress on a fuel mileage question without doing it on a dyno or over a long period of time.

 

This point needs to be emphasized. If you're judging MPG on the basis of only a few fill ups, your margin of error could easily be a few MPG just on the basis of different fuel pumps being calibrated to stop at different levels. Throw temperature and driving conditions into the mix and you are flying pretty blind for determining MPG at home with just a notepad and a calculator.

[scorch]

As for fuel system cleaning, can you guarentee that the gas you are using is clean? Especially nowdays when regulations are being lifted.

 

What are you referring to? Gas has never been cleaner than it is today. And besides, what did you think that little thing called a fuel filter was for? Is yours missing? If so, you should put one back in right now! If it's still there and you are replacing it when Subaru says you should, it would seem reasonable to me to assume that it's doing its job.

 

I don't know what kind of "fuel treatment" you shelled out $200 bucks for, but the only thing of much importance that a garage can do along these lines is a pressure flush of your injectors (for high mileage vehicles, mostly), and that's going to run you more than $200. I'd be curious to find out what this "fuel treatment" actually was.

 

A few years back my parents Toyota had broken down (throttle control) so they checked the fuel. I still remember looking at the jar and seeing all the chunks floating in it. Therefore I justify cleaning the system.

 

Again, your critical reasoning skills are leading you to some hasty conclusions. Do you know what those "chunks" were and where exactly they came from? Do you actually think that "chunks" are a normal thing to find in gasoline? And again, do you think that your fuel filter is incapable of doing its job?

 

The kinds of concerns about the quality and cleanliness of gasoline that you have seem to be based on nothing more than hasty conclusions drawn from limited and questionable anecdotal evidence. But even if gasoline was really dirty as a rule, the only problem it's going to cause you is some stalling every few years as your fuel filter clogs up prematurely.

 

And as to your hood scoop mod, I'd be curious to know what your qualifications are to determine that such a change would be beneficial. Because given your posts on this thread, no offense I have a hard time believing that you are trained in the fields of aerodynamics and automotive science.

 

I'm not saying this to be insulting to you, but to emphasize your flawed thinking so that other people reading this thread won't be misled by it.

[scorch]

What was the point in removing the bottom of the scoop? Allow water to drip on FPR's and Coil pack???

 

Perhaps the point was to feel smarter than Subaru's design team.

[nipper]

Perhaps the point was to feel smarter than Subaru's design team.

 

 

hehehall those millions spent on design and wind tunnel testing, not to mention enviormental teasting, what do they know

 

nipper

[nipper]

What are you referring to? Gas has never been cleaner than it is today. And besides, what did you think that little thing called a fuel filter was for? Is yours missing? If so, you should put one back in right now! If it's still there and you are replacing it when Subaru says you should, it would seem reasonable to me to assume that it's doing its job.

 

I don't know what kind of "fuel treatment" you shelled out $200 bucks for, but the only thing of much importance that a garage can do along these lines is a pressure flush of your injectors (for high mileage vehicles, mostly), and that's going to run you more than $200. I'd be curious to find out what this "fuel treatment" actually was.

 

 

 

Again, your critical reasoning skills are leading you to some hasty conclusions. Do you know what those "chunks" were and where exactly they came from? Do you actually think that "chunks" are a normal thing to find in gasoline? And again, do you think that your fuel filter is incapable of doing its job?

 

The kinds of concerns about the quality and cleanliness of gasoline that you have seem to be based on nothing more than hasty conclusions drawn from limited and questionable anecdotal evidence. But even if gasoline was really dirty as a rule, the only problem it's going to cause you is some stalling every few years as your fuel filter clogs up prematurely.

 

And as to your hood scoop mod, I'd be curious to know what your qualifications are to determine that such a change would be beneficial. Because given your posts on this thread, no offense I have a hard time believing that you are trained in the fields of aerodynamics and automotive science.

 

I'm not saying this to be insulting to you, but to emphasize your flawed thinking so that other people reading this thread won't be misled by it.

 

What he said

 

nipper

[brus brother]

Now I'm on board!

If I have a cold and I eat pizza... my cold eventually goes away.

[Slegacy96]

I see I have many questions to answer.

1. I dont do anything to keep water or leaves out of my scoop. The scoop is pretty shallow and water hits the airbox and rolls of the back.

 

2. Yes I have reasoning skills, I mean come on I go to Penn State. We are all smart...especially me.

 

3. My fuel cleaning consisted of cleaning the injectors, replacing fuel filter, etc. Mind you I had around 77K at the time.

 

4. I didnt say specifically that doing something like opening up your scoop will net you XX increase in MPG. I said that the COMBINATION of what I did yielded me an increase from 28 to 32. The increase was a result of what I did. NOT because of changes for summer gasoline. It was not summer or anywhere near it.

 

5. Gas is not as clean. President Bush is lifting quality regulations, giving us more crude burning fuels in an effort to reduce gas prices. Where have you been?

[Slegacy96]

You dont have to believe me if you dont want. My tips were a mere suggestion to help you, not me, Im already gettin the results. My increase is not a coincidence.

[Slegacy96]

What are you doing to keep water and debris out of the intake? Or did you not mod the intake to meet the scoop? If not... What was the point in removing the bottom of the scoop? Allow water to drip on FPR's and Coil pack???

 

Doesnt drip onto the coil pack. Once again, it rolls over the airbox. Believe me it hasnt been a problem. Through pouring rain yesterday (and hail. NOOOO) and the winters of central PA.

Though not everyone has one. My '96 didnt.

 

And no I havent done any Mod to the intake. Considering a short ram.

[Slegacy96]

Hang on let me get this straight. Nipper you are agreeing with Scorch on all that he said. Including that the fuel filter stop debris from entering your system, thus it does its job. So then all filters are perfect?

1. Why does the fuel system ever need to be cleaned then? How would soot accumulate if the filter is perfect.

2. Whats wrong with my K & N. You agreed that all filters are impenatrable. Over LGT, we regard the K & N with great esteem.

[nipper]

I see I have many questions to answer.

1. I dont do anything to keep water or leaves out of my scoop. The scoop is pretty shallow and water hits the airbox and rolls of the back.

 

2. Yes I have reasoning skills, I mean come on I go to Penn State. We are all smart...especially me.

 

3. My fuel cleaning consisted of cleaning the injectors, replacing fuel filter, etc. Mind you I had around 77K at the time.

 

4. I didnt say specifically that doing something like opening up your scoop will net you XX increase in MPG. I said that the COMBINATION of what I did yielded me an increase from 28 to 32. The increase was a result of what I did. NOT because of changes for summer gasoline. It was not summer or anywhere near it.

 

5. Gas is not as clean. President Bush is lifting quality regulations, giving us more crude burning fuels in an effort to reduce gas prices. Where have you been?

 

 

Fuel is still cleaner then it was 10 years ago. Fuel has to meet a standard set by the auto manufacturers. The Auto Manufacturers were about to start a program certifying brands of gasoline over others as cleaner. Well let me tell you, that put the fear of God into the fuel companies (moreso the tiny off brand piss water). The MFG were seeing to much warrenty work on injectors from the midwest and southwest.

Cleaning an injector that has no running issues really is a waste of money. AT 77K there was noting wrong with your injectors.

A 4mpg increase can be done at your right foot easily. Also soobies arent really broken in till 100K

ALso it could be from using winter air in summer tires (hehehehe)

 

nipper

[Slegacy96]

AT 77K there was noting wrong with your injectors.

 

Also soobies arent really broken in till 100K

 

nipper

 

No need for cleaning, I strongly disagree. Read your Haynes Manual.

 

100k? Tell that to my '96 :-\ Still faired better than my prelude

[nipper]

No need for cleaning, I strongly disagree. Read your Haynes Manual.

 

100k? Tell that to my '96 :-\ Still faired better than my prelude

 

i dont see the haynes reference. ALso look here http://www.cars101.com/subaru/subaru_maintenance.html#90-99maintenance no mention of a fuel injector cleaning.

 

Kand N filter, there have been extensive studies showing that they are worse at filtering air then OE or other brands. http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

Also there are electronics down stream that can be damaged by allowing dirt or oil get in the air, depending upon the year of the car (you can do a search on that too.

If filters were inpentrable, they wouldnt be filters, they would be plugs. Filters allow things through at the micron level.

But hey im just in the automotive industry at the engineering end, what do i know.

 

nipper

[shortlid]

i dont see the haynes reference. ALso look here http://www.cars101.com/subaru/subaru_maintenance.html#90-99maintenance no mention of a fuel injector cleaning.

 

Kand N filter, there have been extensive studies showing that they are worse at filtering air then OE or other brands. http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

Also there are electronics down stream that can be damaged by allowing dirt or oil get in the air, depending upon the year of the car (you can do a search on that too.

If filters were inpentrable, they wouldnt be filters, they would be plugs. Filters allow things through at the micron level.

But hey im just in the automotive industry at the engineering end, what do i know.

 

nipper

 

K&N's CAN damage your Mass Air flow sensor if you are a idiot and put to much oil on the filter. I have run then in most of my vehicles including a '93 Toyota Corolla with 325k. Good compresion across all cyl. and a VERY clean TB. They can't be that bad if properly maintained!

[Ranger83]

You dont have to believe me if you dont want. My tips were a mere suggestion to help you, not me, Im already gettin the results. My increase is not a coincidence.

 

And the tinfoil helmet - is that worth an additonal 2mpg? 4mpg?

[Andyjo]

The problem w/ the K&N is that most people Don't know how to keep them properly maintained. You should also take note that the MORE air you get the MORE fuel you can burn... yielding less milage... get it?

 

The hood scoop: if you take the backing plate out you WILL recieve a higher drag coefficient, why you may ask? it's all about the pressure bouble it creates in front of the scoop, which keeps the flow laminar over the scoop, opposed to slaming into it and creating a turbulent flow before it normally would (around the top of the windshield or so... Re ~=500,000). Now if this theoretical explination isn't enough for you, i've done an experiment myself. Last summer, road trip, from VT to Strakes' house (TN), 3 tanks of gas w/ the backing plate in, 3 takes w/o the plate, and what do you find? you get better milage with the plate in, with the plate i was averaging 28-29mpg, without i wa getting about 27-28 (2 drivers for each control, to even out the data). These tests were controled to roughly 65-70mph, windows open most of the way.

Now, this isn't a HUGE loss, but it goes to show you not to mess with your car's aerodynamics. I'm currently running my obs w/o the plate.. but that's only because i lost it in our basement somewhere

If you really don't believe me, next time i'm back at school i'll fire up the stereolyth machine and do some wind tunnel tests for yah.

 

Fuel Filter: It filters your fuel, it doesn't matter how crappy the gas (if it hasnt' gone bad already) your filter will most likely spit out something that your engine will enjoy, and keep all the junk in the filter. I had a noticable increase in milage after i changed mine, at 160k.

 

Fuel Injector Cleaning: Go to your local auto store, pick up some Lucas Fuel injector cleaner, dump it in your gas tank, and away you go, no need for dumping 200 bucks on something you don't know the exact process of.

 

Alot of these things can be mental, you can think that you're driving the same... but your foot isn't... you can beat the piss out of your car, and maybe the conditions (pressure, density, humidity, etc..) are optomized for your milage? who knows.

 

Just a quick question, what are you doing at Penn. state? Science, Engineering, Arts, Buisness, etcc.. ?

 

And the tinfoil helmet - is that worth an additonal 2mpg? 4mpg?

Hey! that reallly works!

[c150L]

SLegacy96, Shame on you for posting what you did and what results you got. Just kidding.

 

I put in a whole bottle of PBlaster fuel system/injector cleaner into 1/2 tank of gas in my XT6 (supposed to put 1/2 bottle to a full tank), and my milage went from 17mpg to 24mpg average. Please bash me for stating what I did and my results.

 

I took my 71 Roadrunners 383 and removed every other exhaust valve, and was doing 24-25 mpg one whole summer, running on 4 cylinders. The other 4 pistons were still going up and down in thier holes. 55mph, no problem. 75mph, no problem, just toook a little longer to get to it. That's what I did, that's the mileage I got. Like it or not.