Clevelandhhrss

Check your average speed over a tank, compared the high and low mpg tanks. Also the number of cold starts hurts mileage also. Parking garages, super steep hills, parking lots, fast food restaurants etc. They also eat mileage right under your nose. I'm sure that you have already though about these things, but don't underestimate how much they can matter even in small doses.

GCarp

Also the route you routinely drive has an effect. Stop and go traffic on a short route gets you less mpg vs less traffic and traffic lights on a longer route. The added mpg more than offsets the additional distance.

I also was kinda wondering if there was anything out there to increase mpg mechanically/electronically - best bang for the buck...

Clevelandhhrss

Probably a tune. No shoe fits better than a cutom one made for YOU. Most other items have a lot of "buck" and not so much "bang".

This lower part is for anyone willing to read, not specifically GCarp

Please don't take this as a bash, burn, or flame..lol

If no one here wants to tune their driving (the 99% consensus from all people i converste with about mileage) then get a hybrid. It will go off electric in the city and below certain speeds, shift FOR you, and will do all the things I do with my clutch and ignition without having to pay attention. You'll get better mileage at whatever speed you choose to drive. It IS POSSIBLE to hypermile doin 80 on an interstate.

Once again dont thake this as a bash Im just making a analogy.

I am reminded of athletes who choose not to do the work (OR ENOUGH) but want the results. They buy drugs, inject , and cheat. I prefer the Jerry Rice or Jack Lalane style of bolt on :).

The Curly 1

Performance and mileage go together in many ways.
Save weight your car will go faster and or get better mileage. Fact. That does not mean I am going to rip out all of the interior of my car to get better mileage. Lower weight= faster acceleration and better mileage because it takes less energy (gas) to accellerate the vehicle.
Better aerodynamics will increase performance and gas mileage. Fact. I am going to lower the vehicle about 2 inches all the way around but that is all I am not going to remove mirrors, antenae etc. Aerodynamics may not mean much at 10 MPH but at 60 or more it is huge. If you think it is not stick you hand out the window and see how much drag it has. Then think about how much air the whole car is pushing. Air drag takes horsepower (gas) to pusg vehicle. The faster you go the larger the difference it makes. Fact.
Increase the effeciency of the vehicle it will get better performance and mileage. Fact. I think right now I am going to put a K & N intake filter and axle back exhuast with a Trifecta tune. I have a friend who says he got 7 MPG better mileage with an Ariad (sp?) filter. He said he has an 11 gallon tank (Pontiac Grand Am?) and he gets over 100 miles more per tank. I am not expecting that much for an air filter but regardless it makes a noticeable difference. I am not going to remove the air conditioner or anything like that. Ideally you want to make the motor and car as effecient as possible with out giving up the creature comforts or safety features. I know for a fact you can increase performance and mileage with better intake and exhaust and tuned for it. I do not know exactly how much it will help and that is really what I am asking here, how much and which is best? Now if you make the mods and then run around wide open all the time then not only will your gas mileage stink you may get a bunch of tickets. The wrong mods will hurt your mileage and lighten your wallet. The right ones will help performance and save you money in the long run in gas savings. I plan on keeping my car for many years so these mods will pay off big time in performance, mileage and fun. Besides this is my baby and I want to improve it some, I already ordered some Solstice wheels, the lowering kit and deciding which other mods to make. I am also going to make some 100 mile trips at the same speed under as close as possible same conditions to verifiy the results. Hoping someone else had already done much of that and knows which ones work best.
Driving is also a big part of economy but certainly not the only thing and not what I am asking about here. There are several good threads on driving techniques but not much real world figures on the best mechanical improvements.
Ethanol will hurt mileage some. In my race car when I was using gas it took about 1 gallon of gas per pass, with Alcohol it takes about 2.5 gallons per pass. The car is MUCH faster on Alcohol though. Alcohol - does run cooler and has higher octane but it requires MUCH more fuel. Even a Ethanol 10% mixture decreases mileage some so in my opinion unless it was about 25% cheaper Ethanol does not make much sense to me in a daily driver.

Clevelandhhrss

Try it and see. Post your experiment technique and results here. Actually make a new thread, call it "Mods for Mileage" or something like that. There is a tune in my future so I will have many things to add.

The Curly 1

"If no one here wants to tune their driving (the 99% consensus from all people i converste with about mileage) then get a hybrid. It will go off electric in the city and below certain speeds, shift FOR you, and will do all the things I do with my clutch and ignition without having to pay attention. You'll get better mileage at whatever speed you choose to drive. It IS POSSIBLE to hypermile doin 80 on an interstate."

Nobody said they do not want to tune their driving here. This whole thread is about Mechanical improvements or "Mods for Mileage" what ever you want to call it. Driving technique has been discussed on this forum before, I just want some good, knowledgeable opinions on the mechanical end of it.

You are apperiently very good at squeezing every last drop out of your car as a driver. That is good, you said in one of your posts that you turn the air conditioning off and crack the windows. Why do you do that? (for the same reason I want to make mechanical mods) Because it frees up some horsepower and saves some gas. The car does not have to work as hard to move the vehicle. You said a tune is in your future, are you doing it for the same reasons as I? to gain mileage? I would like to know how much a tune helps your car.

Nobody is dissagreeing the driver is important if your goal is gas mileage but the car is to and there are things you can do to improve it.

Turning the air conditioner off will help as will a tune, an intake filter, aero dynamic mods, exhaust system and yes driver to.

For my car I ordered a set of Solstice wheels, lowering kit, K & N filter, CGS axle back muffler system and going to do a Trifecta tune on it. Solstice wheels will not help mileage any but I like the way they look. I like the car and I will like it even more when the mods are done if they work as I think they will.

I am making some 100 mile test runs as a baseline and recording weather etc to get the most reliable results possible. Then I will do the lowering and test it again. I will know in a month or so how much the mods for mileage help and will post them here.
I do not want to make a job out of it I just want get better mileage and then enjoy the car. Curly

Clevelandhhrss

Sounds good. Post with the same detail as my post. Plenty of silent views are interested. And loud mouths like me are really interested. I have not done a acceptable job testing air conditioning vrs windows cracked. I work in (50% of the time) in a harsh industiral environment. It always 90% humidity and always 10-15 degress above ambient in the COOL areas. So I work in the amazon weather 5 months out of th year. 90 degrees and windows down feels cool to me. I only run the a/c when my sons is riding with me. If it wasn't for that , I wouldnt have any use for A/c. It just dosent get that hot TO ME. Try the mods. let us know. If you can get me to 40 mpg, you will be the MAN.

The Curly 1

From what I can tell it is going to be very difficult to get exact mileage improvements. The test run was mostly uphill on the way out and down hill on the way back. Mileage was about 3 MPG better on the return trip. On my test runs today I made a bunch of 10 or more mile tests at different speeds from 55 to 85 MPH. Atleast 2 test runs at each speed more than 10 miles each direction.
39.75 MPG average @55 MPH
37.1 MPG average @ 60
35.7 MPG average @ 65
31.1 MPG average @ 70
29.9 MPH average @ 75
29.1 MPG average @ 80
26.3 MPG average @85 MPH
Temperature was 90* and the alitimeter was at 450 feet above sea level with very little if any wind today. All the way I set it on cruize control and treid to keep it as consistant as possible to get accurate figures. Of course there are driving things I could do to improve that some but I am trying to get good numbers for before and after of my car.
My average city MPH is 22-24.

Several of my numbers really did not seem as consitant as I think they should have been and everal times I had someone pull in front of me where I had to slam brakes and then accelerate back up to speed so I know that may have hurt some.

I did a very short 60 MPH run with the air conditioner off and it was like being in an oven but the mileage went up from 37 average at that speed to 44 average. That seems much more than I expected so I will try to do that test again to verify. Has anyone done any mileage tests with and with out air conditioning??
I hope to do all of these again next week to get a better baseline prior to making the mods.
I am going to try to do the tests with the lowering only first as I want to know if that makes any difference, I know it should at speed but no idea how much.
I am hoping (expecting) 5 MPG gains on the highway at most all speeds and maybe 3 MPG in the city. I would not be suprized to see a few more MPG than that. Regardless everyone will know in about 4 to 6 weeks when all of the tests and mods are done.

The Curly 1

I put about 240 miles on the car today doing the testing. The altitude climbs from 437 feet to about 1250 feet above sea level over the 120 miles before I turned around to make the return trip. Also started out with about 3/4 tank and there was less gas in the tank on the return trip so that lightens the car up some. Those two things probably accounted for about 3 MPG better mileage on the return trip at most speeds.
I will try to do all of my testing on this very same test road under as close as possible weather conditions. Each variable does make it difficult though. Curly

jonathanm

I would LOVE to see the MPG at lower speeds as well, my gut says there has got to be an ideal MPH for mileage, and your chart shows continual gains down to 55.

I just got my 2008 LS 2.2 5sp AA5 two weeks ago. I forgot to reset the DIC after the first tank, so for the first 2 tanks I got 32.1MPG average, at 35MPH average. I'm at 35.1MPG and 38MPH average after about 100 miles on the third tank. This is a mix of around town and highway, probably 40/60 overall so far.

I'm seriously impressed at the MPG I can get out of this car (truck). The DIC makes it impossible to not pay attention to my right foot. My other cars are big V8 sports cars, so I'm used to getting 10-15MPG, and not caring how hard I accelerate. The DIC scolds me every time I put my foot in it with the HHR, so I'm that much more aware of my driving style.

Curly, I'd also be interested in an all windows down at 75, and 55 data point. I suspect it will be more of a drop than the A/C, judging by the buffeting I feel.

Jonathan