First 55+ mpg tank for my '08 Cobalt XFE

[Fr3AkAzOiD]

Originally Posted by Jammer

If it was not for Fr3AkAzOiD making these posts I would likely figure my car had already maxed out all it will do on gas mileage. Now I think I can get a little more out of her.

Thanks a lot!
I actualy took your advise and dropped a couple psi in my tires. At 60 degrees they run warm at 44 psi and at 80 degrees warm is 46 psi though 80 degrees was a bit of a freaky warm day for October.

Ran from Raleigh, NC to Bryson City, NC in the mountains driving between 65- 70 mph (about 330 miles each way) and around town quite a bit for a friends wedding. The Cobalt is not a good rally car, it was not happy climbing small mountain gravel roads but still round trip ended up with 45.625 mpg which is better then expected and Jammer if the roads I was driving are anything like the ones around your way then you should be very proud of your lifetime average.

Going down the side of a mountain highway at 75 mph with the engine off was a bit too much for even me so I mostly just keep it running but in neutral. Certainly were a lot more variables in that trip then my normal round trip to and from work.

Thanks everyone for your support and hopefully before this time next year I'll be making a post that I broke 60 mpg.

[Jammer]

I think you made a smart move by taking out a little air from your tires. I feel their comes a point of no return, and too much tire pressure is a leading cause of wear to the sides of tires while the center tread may seem much newer. It happen to me in a previous pickup.

BTW: My tire pressure was going down along with the average temperature outside, and it kept sliding downward until I started seeing 35/36 PPSI I figured it was time to raise it back up close to the MAX again. I filled up all 4 tires to 40 ppsi COLD, and on warmer days and/or long trips my pressure gets up to 43ppsi. That's exactly where I like it- 1 found on a warmer day with a lot on miles put on it, as long as it does not go above 44, as Goodyear has put that number on the tire for a reason, then I am most happy. Too much tire pressure makes taking corners difficult too. The first thing I noticed with the higher gas mileage! I gained 3/10ths on my AVG MPG Display- right from the get-go!! Now my record high is 45.7 MPG AVG - I have a picture in my album folder on profile here, and it is also in the thread out my car in Success Stories.

I really do believe my car is very near it's max with fuel economy unless something like an oil change and tire rotation might help, because that is the next big thing for me to do, and for as little $$ they charge I might have it done in town and stand back and watch them so they can get spooked1 haha- Naw, I can normally trust these kids to do what they say. For the price of the oil and lube, not to mention my own lack of knowledge, I don't think it's too bad a deal for what this little place in town charges. I just hope getting all of that break-in oil out might help my MPG, at least a few tenths

Here is MY All Time Mileage Record for my 2009 Cobalt XFE starting on the very day I picked it up brand new with 133 miles on the odometer and 25 MPG AVG (the dealer had the car driven over from out of state which I had agreed too) - The MPG gauge has NOT be reset, but I am aware of how to do it if I choose to. I just rather have an all time average for the time being. I am having a hard time getting above this record of 45.7, but I can see that my odometer is on a path way of ever so slowly making it higher, and that includes short trips in 70MPH zones.


WOW 45-55 MPG driving CHEVYs! Whoa would of "thunked it" a couple years ago?? Just today I was directly behind a Toyota Prius Hybrid and I got to thinking to myself... I bet this driver don't practice hypermiling. And if he does not, I would think it's mileage is close to the EPA reported 50MPG. In which case the OP here has already shown an inexpensive Chevy can do it, and I'm darn close behind. Then I think about the difference in the price of the cars, and I know I made the right choice. I admit I am impressed by the hybrid Prius. But for the price my Cobalt cost me, and the fact I am almost getting 46 AVG MPG all time driving, well it just makes me smile. What is not so cool is that I still have yet to see another Cobalt XFE in this county!! I think I am the only one, and it certainly would explain why the police often glance my direction just long enough to see me and then go another way. They leave me with an impression they know my car, and with that 7 foot cb antenna and the rest, it makes sense.

[Burnt]

Originally Posted by Fr3AkAzOiD

Also have a pexiglass lower grill block that has been showing a good 1 - 2 mpg improvement. I plan to replace it with a better looking and more sturdy version and will document that on here when I get around to doing it.

Hey freakazoid, I would love to see some pictures of your grill block, and maybe a little description on how you went about putting it in - I'm planning to put one in on my XFE asap....I'm not mechanically inclined at all, but a grill block looks like an easy install, some pictures would definitely help me

I'm also going to raise my tire pressure from 31 psi (from the dealership) to around 39-40 psi today....

since I started hypermiling in earnest, and trying out EOC, my 2 day 80% city driving is at 38.1 right now, with no mods on the car yet. I think thats not too shabby for a beginner. I'm worried about snow though......

Jammer - I'm going to change my breakout oil too; I don't think it's been changed since the car was originally bought (I got it from the dealership @89% with 3.4k miles, down to 83% now).....I've only had the car 2 weeks....do you think I should hold off, or change the oil now?

[Jammer]

Originally Posted by Burnt

Jammer - I'm going to change my breakout oil too; I don't think it's been changed since the car was originally bought (I got it from the dealership @89% with 3.4k miles, down to 83% now).....I've only had the car 2 weeks....do you think I should hold off, or change the oil now?

I wish I had the answer. Based on the manual to my 2009 XFE it claims the days of needing to change the oil every 3,000 to 5,000 miles is behind us, depending on what the computer claims the condition of the oil is. I have around 6,000 miles now and my computer still claims my oil is about 60% GOOD! (Or is that 60% BAD??) Either way as soon as the temps started going down my gas mileage started going down AND my battery has already gone dead one me 2 times. Whomever got the notion of sticking the car battery in under the cold false trunk compartment should be fired. Because of where Chevy stuck the battery in my car it makes it most difficult to keep the battery charged and be able to practice driving in EOC very much when it is colder than 45F.

Within a month I hope to change my oil and rotate all 4 tires as well. If were all going to push our tire pressure close to the max, then I feel we need to rotate the tires every 5,000 miles or whatever so the tire wear will be most even. imho

My Best.

[CoastRider]

Originally Posted by Fr3AkAzOiD

Going down the side of a mountain highway at 75 mph with the engine off was a bit too much for even me so I mostly just keep it running but in neutral.

would have been better off leaving it in gear and staying off the gas.

With no throttle input and within proper speed rpm vac the ECU shuts off the injectors.

[MetroMPG]

Originally Posted by Jammer

AND my battery has already gone dead one me 2 times.

If the battery is going dead from EOC, you need to monitor voltage to decide when the charge is too low and you need to leave the engine on. (A $3 harbor freight voltmeter will let you do this.)

You probably already know that deeply discharging a conventional starting battery (eg. to the point it won't start the car) damages it, reducing its capacity even further each time it happens.

If you're trying to save money, having to replace your battery every year or so will cancel a big chunk of your gains!

[Jammer]

Originally Posted by MetroMPG

If the battery is going dead from EOC, you need to monitor voltage to decide when the charge is too low and you need to leave the engine on. (A $3 harbor freight voltmeter will let you do this.)

You probably already know that deeply discharging a conventional starting battery (eg. to the point it won't start the car) damages it, reducing its capacity even further each time it happens.

If you're trying to save money, having to replace your battery every year or so will cancel a big chunk of your gains!

Well, out of all the areas I have driven too, so far where I live it just happens to be the best location I can find for using EOC to gain MPG, so I tend to want to use it a lot here. But I now feel whenever the outside temp gets cold I had best not use EOC at all without further damaging the battery. I run with a Stereo, CB Radio, GPS, Radar Detector, and sometimes a Cell charger all on WHILE the heat is on!! So, I think I can see what is happening here, and I don't think a volt meter (while a nice plus) would help me much. I find I can get away with driving this way on warmer days, but I can not keep by battery charged running so much electricity while using a lot of EOC on cold days with a battery located outside of my engine compartment.

I might get around to getting a volt meter for display some day. It may very well help me figure out just exactly where I'm pushing my battery too far.

Thanks

[discovery]

Chevy 55mpg wow, keep up the good work, post some pic.

[Fr3AkAzOiD]

Sorry I havn't been around too much, my daughter was born on 11/04 and my wife and I have had our hands full trying not to screw up our first born.

To Burnt: Though not proven some people have the theory that fully inflating tires before some sort of break in period can cause problems in the future, while I don't have links to specific web pages I have seen it brought up on the forums a few times. I would recommend incrementally increasing the tire pressure.
Maybe start at 35 psi and increase 2 psi every thousand miles you go.
Due to freaky temps my fluctuate from 39 psi warm @ 40 degrees (9pm yesterday night) to 43 psi warm at 70 degrees (9pm tonight). I would keep that in mind when inflating your tires.
As for pics....the block I put up was my first shot and only temporary, it is actually in bad shape now. I used Plexiglas and took a small stone to my lower grill which cracked it, but I guess better my grill block then it hitting my radiator.

I am planning a more permanent lower grill block but I just need to find a lost bumper. I plan to make the lower grill block on the outside instead of the inside of the grill and have a piece of flat car bumper cut and colored to match. You would be surprised how often I see a bumper along the side of the road from where someone had an accident. Seen 2 in the last 6 weeks alone. Unfortunately both times I already had a car full of stuff and I was unable to pick it up.

I will take pics of my old grill block then as well as making my new one. I also picked up some mirrors and I plan to take off the passenger side mirror and make an internal one but my wife and I are having a "discussion" about that. My main talking point is of increasing mpg and saving gas and money, hers is that she doesn't want to be seen in an ugly car.
Guess I will just have to wait till she goes out of town with the baby to do it, maybe she won't complain too much once it's finished.

To Coastrider: I believe the fuel shutoff was a feature added to the Cobalt in '09 that was not part of it on '08. One of the things that gave the '09 a rating of 1 mpg higher then '08. When I coast in gear my mpg meter will always display lower mpg while being in gear vs being in neutral. While your advice is good it will only benefit those that have a fuel shutoff while in gear feature in their car.

To Jammer: You definitely need to watch it when running multiple electrical items if you are going to EOC. When I EOC I am just running the radio and vent fan/heat. When it is raining, especially at night I don't EOC. Not just due to the extra danger in doing so but when wipers and headlights and window defroster are running a battery can be drained pretty fast. I have already seen my numbers start to drop and doubt I will be able to pop over 50 mpg will next spring.

To discover: Due to popular demand I will try my best to get a pic thread started when I have off Sunday and Monday.

Off to change a diaper......
I feel weird, helping the environment by using less fuel and then turning around and going through 10+ diapers a day. My wife and I are in "discussions" about going to more Eco-friendly cloth diapers. I'm for it but she is for "the convenience" of disposable.

*sigh*

[Burnt]

Originally Posted by Fr3AkAzOiD

I will take pics of my old grill block then as well as making my new one. I also picked up some mirrors and I plan to take off the passenger side mirror and make an internal one but my wife and I are having a "discussion" about that. My main talking point is of increasing mpg and saving gas and money, hers is that she doesn't want to be seen in an ugly car.
Guess I will just have to wait till she goes out of town with the baby to do it, maybe she won't complain too much once it's finished.



To discover: Due to popular demand I will try my best to get a pic thread started when I have off Sunday and Monday.

Off to change a diaper......
I feel weird, helping the environment by using less fuel and then turning around and going through 10+ diapers a day. My wife and I are in "discussions" about going to more Eco-friendly cloth diapers. I'm for it but she is for "the convenience" of disposable.

*sigh*

Hey freak - I have an 18 month old and my wife and I have been using cloth diapers during the day and a disposable at night....tell your wife she would actually be really surprised how easy cloth diapers are.....they really are no big deal, only minimal more effort than disposables, and trust me I was NOT thrilled when my wife decided to use them

if you're worried about the "poop factor" with cloth diapers, you could use disposables till your baby poops, then switch to cloth, to at least save a couple diapers


here's something called bumgenious....I guess a lot of people use this

http://www.youtube.com/watch?v=0-_xmEWy00A

We use thirsties; made in the USA, saves about $40/week in disposables
http://www.thirstiesbaby.com/products.htm

http://www.youtube.com/watch?v=R_3b65KSH_w

we wash them every 3-4 days


I'm looking forward to your pics thread....it's freezing here in ohio, so it's a good time for a block