bugflipper

Since OPEC is dead set on lightening our wallets. What can we do about it? I personally have a k&n cold air kit. A fuel attomizer. Run synthetic oil. And a round straight through muffler. 2.4 auto gets 32.7 mpg avg, mostly highway at 65mph. Looking for any additional power improvements to increase mpg.
And also does lowering a vehicle increase fuel econmy?
Thank you.

Old Lar

You are already getting better mileage than the car is rated. The only other thing I can suggest is to slow down. I do a lot of coasting around town, and try to get into lock-up (around 40 mph @ 1500 rpm) in town. Keeping the 2-3 seconds between you and the car in front so you don't need to brake (coasting). www.cleanmpg.com has other hints.

catdaddy137

i'd say you're doing great , i have 08 2.4 auto, 270+ miles , 6 days week , 200 on hwy, i have NEVER got even close to 32mpg , and i try real hard. i am very inerested in the mods you have made. could you please list them in more detail? i have gone from 24mpg to 26-7 just by my driving habits and keeping the tires above 35psi cold , they are at 40 now warm. i want larger tires-some debate about weather this will help mpg , but i believe it will , probem is there is only limited amount of space in the wheel wells for this.

The Curly 1

I am working on the same things. To answer one question, Yes lowering should help mileage.
I used Goldline lowering springs to lower Princess about 2 inches all the way around. It did improve mileage some but hard to say exactly how much. THe big improvement with lowering was the cornering and ride was soo much better! The car does not move around much in bad cross winds now and just feels like it is glued to the road. I had hoped for maye 2 MPG at highway speeds and I have not been able to difinatively prove it. I can say for sure it has not hurt mileage.
My plan is too build the car to get the best mileage possible with out hurting the looks or performance. So far I have:
1. lowered car (less wind drag)
2. Airiad intake filter
3. 2.4 Intake manifold (more air in and out increasing effeciency)
4. 2.4 exhaust including cat and downpipe with Cherry Bomb Vortex muffler
5. Air Dam (Home depot garden edging)
6. Taller tires and Solstice wheels, (lowering RPM)

My mileage in the city has went from 21 to 26 and on the highway at 70 from 29-31 to 35-36. Also note my tires are a little taller so my actual mileage now is about 2 MPG better. My next mods are:
1. 2.4 Throttle body
2. 2.0 exhaust manifold or header
3. Trifecta tune (this is what should bring it all together to work as one)

I was considering an underdrive pulley system but on the Ecotec motor it is probably of no help. Chevy only has the air conditioner and alternator on the crank pulley so it does not have much horsepower robbing accesories on the the crank.

Right now my car is not tuned for the system I have. When I do the Trifecta Tune I fully expect it will pick up much more. I have felt that way from the beginning and can not wait to prove it. (Hope I am right!) My goal is 28/40 or better with machanical mods then I work on driving style.

With that said you can also do what the call "Hypermiling" and get much better mileage with out making any mods to the car only the driver.

I am also learning that there are many other variables in getting consistent, reliable, repeatable results. Wind, altitude, air temps, fuel mixtures and other things all effect it. I use an altimeter a lot in my testing because it will tell you for sure if the road is flat or not. Many roads look flat but are slightly uphill or downhill and that makes a huge difference.

The Curly 1

I believe a taller and more narrow tire would give you about 4 to 5 MPG better. My Solstice wheels and tires helped some but they are wider than stock and that hurts mileage. I picked up about 2.5 to 3 MPG with the taller tires and they are wider! Just think what a good narrow tire would do especially if you had some moon hubcaps to help aero dynamics.

I am not going to change now because I have a brand new set of wheels and tires but I definatly think I could have made a better choice in tire size.

bugflipper

Catdaddy, I don't have time right now on my way for work. I will get you some links posted up tonight hopefully.

Curly 1, need a little input on that air dam, how did you attach it to the bumper? Also is the mpg off your DIC or calculated by you?
Thanks guys. Very helpful tips.

bugflipper

http://www.fuelconcepts.com/how.htm
Here is the fuel atomizer. Supposed to be the only one that truely works. Takes a very small amount of fuel off the fuel rail. Puts it into the intake via what was the pcv valve. Is a bit finacky to get dialed in, but it does work.

http://www.knfilters.com/search/prod...x?Prod=57-3056
Of coarse you know what this is and what it does.

http://www.amazon.com/gp/product/B000CIMH1A
There are two model fo this, one chevy and one ford. It increases the line pressure on the transmission for less wear and firmer shifts. Will chirp second gear stock. Mine will leave 1 foot black marks when it hits second wide open throttle.

http://www.goerlichs.com/product_sub...ducts_xssl.asp
I talked to the guy that owns the muffler shop, this is what he put on. It has a stock cat. Stock resonator then 2.5" from there to muffler. He told me the resonator is hollow, that's why it has such a good rumble, refereded to the factory resonator as a bass tube. Cancels out obnoxious noise before it goes into the muffler. They put a flow meter on the throttle body. I told him eventually I may do more work. So they got the exhaust system to flow the equivelent of a 2 1/4" open pipe. The muffler is round and has a single 3" tip. It is hollow in the middle with a mesh screen and steel wool for deadening. Some what like the inside of a glass pack but no louvers, just a 3" inside diameter wire screen. It's a straight shot through.
The wife has been driving it lately complains about all the little kids in mustangs revving up wanting to race at stop lights. It does sound like a mustang with a good set of mufflers, not the obnoxios ones that rattle windows and have the mettalic sound.

BTW in low it will leave black marks for 10 foot with this setup. Not to shabby for a 4 banger
And the fuel milage, I live on a mountain that brings the average way down to climb it. On flat ground the DIC says 42.8 at 65mpg. My calculated milage is 31-33, the DIC is very close always around 31.2-33.1.

catdaddy137

well my poor old firehawk gtas have 41psi in them today , with over 40,000 on them , the little dry rot cracks are lookin a little scary.everything else on my 08 2.4 auto is stock. because of heavy fog i had to run a little slower today. my dic -dash computer thingy- , still hasn't caught up , from the prior miles , but i know i was getting over 30mpg . it was so foggy i had plenty time to watch my dash , and i'm ussually doing 65 - 83mph. at 55 it stayed above 35mpg. at 65 it was around 30mpg and mostly above. also when i fill up it usaully says 400 and a little change to empty. today it says 528 miles to empty ! ! ! i really believe some taller tires would help my mpg , since i'm on the hwy so much. i think taller tires in the city would hurt the mpg. oh , my firehawks are not down to the wear bar , but they is real close. the reason i'm writing so much about tires is that i know i got to have some soon , so i want to put taller ones on and see what happens 1st to eliminate confusion about which mod did what. any suggestions on tires would be great.

GRUMPEE

Interesting that you guys are going for tall tires, whereas if you look at the Prius and insight, and other hybrids' tires are either smaller diameter or stock size. ie...The MFGer's of these hybrids are equipping their vehicles with low rolling resistance tires to squeeze out any last bit of fuel economy .

My I find cleanmpg.com to be interesting with a lot of information - but other than that nothing else. I asked to be removed from their membership after realizing i didn't agree with their view & attitude towards non-hypermilers aka fuel sucking pigs - I guess every forum and their members can be thought of as elitists if you disagree with their thinking.

The Curly 1

Funny you should say that. I have also seen some of the people on the forums be real jerks. Clean MPG is the worst, I tried to go on there and learn how to increase my mileage. Thier attitude is they are doing you a favor of blocking you on the highway forcing you to go 45 MPH. They act like some guy Wayne Gertes is a god and everyone must do as he says. Some of them think it is cool to do a "Brake Check" if you try to get around them.
Ecomodders.com has some good people on there who will help you and do not get pissed if you do not drive a Pruis or go over 45 on the highway.

Now to your question of tires. The factory uses small tires on the Prius etc because they are narrow and lightwieght both of which are good for mileage. They have those cars geared very low so it is not turning many RPM's.
Now our cars are geared so they are turning 3000 RPM or more on the highway. Putting taller tires on there lowers it some with out having to change the gear ratio. Narrow tires have less rolling resistance and turn easier to.