First 55+ mpg tank for my '08 Cobalt XFE

[Fr3AkAzOiD]

Distance 282.2 mi.
Fill amount 5.086 US gal
MPG Details 55.49 US


Pumped tires up a bit more, running them at 47 - 49 psi warm which is like 46 psi cold, 2 psi above sidewall rating.

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.

Started my tank out on Sunday morning after I filled up at my local gas station. With good weather and no traffic, did 42 mph the majority of the way to work. From the gas station to work (35 miles) I had an average of 58.1 mpg, on the trip home (slighly more uphill) it dropped to 57.4 mpg.

With such a good start I tried to push it for the hole tank but drizzle and slightly more traffic for the next 2 days had me pick up my speed to about 48 mph and drop my mpg down to 55.1 mpg.

Fourth day was clear so I was able on my last round trip to and from work to bump it back up to the 55.49 mpg I ended it at.

Would have liked to have made it a propper 500+ mile tank but heading across state tomorrow for a wedding and I wanted a seporate consumption report for that round trip so I ended my tank early.


Was also able to obtain a 3 tank average of above 50 mpg and continue to hold it through 2 more fill ups.

My 5 tank average is 51.786 mpg.

I don't expect to hold it with this trip coming up but in the meantime....go Team Chevy!!!

[cfg83]

Fr3AkAzOiD -

Most Egg-Salad!

CarloSW2

[Fr3AkAzOiD]

Originally Posted by cfg83

Fr3AkAzOiD -

Most Egg-Salad!

CarloSW2

Huh?

[MetroMPG]

Nice work, zoid!

Thanks for posting your speed stats as well - good to get the MPG figures in context. I take it "driving with load" is your main technique then?

[cfg83]

Fr3AkAzOiD -

Originally Posted by Fr3AkAzOiD

Huh?

It means Excellent, like so :

Egg-Zactly
Egg-Salad, Smithers!

Soooooo, Egg-Salad is the highest complement, unless you're allergic to eggs.

CarloSW2

[Fr3AkAzOiD]

DWL hasn't worked well for me. Luckily I'm in a mostly flat area with a lot of farms.

What I generaly do is if coming up on a hill with a low grade I'll hold my speed and while on the flat at 40 mph I'll usually get 58 - 60 mpg if I hold 40 on the slight upgrade hill it will usually drop to 38 - 42 mpg depending on grade.

Now with steeper hills I'll hold 40 mph as long as possible and my mpg will slowly start to drop and then at around 36 mpg it will take a sharp drop to around 24 mpg and keep dropping depending on the steepness of the hill.

As soon as it drops off mpg wise I'll downshift and floor it up the hill. Generally the difference of holding 40 mph and accelerating is 22 mpg vs 18 mpg except when I get most of the way up the hill while flooring it I'll have gained 10 - 15 mph at which point I try to time a neutral coast so that I am back at 40 mph when I hit the plateau as I've noted better fuel efficiency doing that versus flooring it all the way to the plateau and then doing a neutral coast or bogging down and having the mpg fall into the teens trying to maintain speed.

My car doesn't seem to do slow accelerations very well. If I'm doing 40 mph and getting 60 mpg and want to get to 50 mph and accelerate slowly, during acceleration my mpg will drop down to the mid to high 30's and then when I get to 50 mph my mpgs will raise to around 52.

Instead I employ a more rapid acceleration keeping my rpms between 1,200 - 2,200 for when changing speeds on the flat or accelerating from a light.

I even went to far as to take a parking space at work that is farther away but is a pull through space on a downhill so I glide into the space on EOC and when leaving I just drop the emergency brake and get the car up to about
10 - 12 mph before I even have to start the engine.

I also got a new garage door remote that has a farther range so I can open my garage door while driving past my neighbors house and EOC all the way up the driveway and into my spot instead with my old remote pulling into the driveway 10 ft away from the garage door, clicking it to open and then waiting a good 30 seconds for it to open and then pull in.

Little things like parking in the garage and then walking to get the mail instead of pulling up to the mailbox, idling for 20 seconds, then accelerating from a stop has added a good 1 or 2 mpg per tank.


I also think I'm very lucky to have a route in which a good portion of it is 2 lanes per side and not very busy and the rest is one lane per side with plenty of passing opportunities so it's not that big of a deal for someone to get around.


My wife thinks I'm a dork and hates to hear about ecomodding/hypermiling.

Though some of it started to rub off when I told her I saved $800 in gas over the past 14 months compared to EPA estimates.

She is getting a good 32 - 36 mpg out of her '05 V6 Malibu though she won't let me make a profile for her.

[Jammer]

As a brother owner of a Cobalt XFE I find your details very interesting. The first thing that caught my attention was your tire pressure. GM advises 30PPSI on my cobalt, the tires claim MAX 44PPSI. I keep them from 39-41 during this weather. I have personally ran tires on air pressure of around 10 ppsi higher than the tire said was MAX before and it made the sides of my tires wear uneven. The only way of making them last would of been a lot of tire rotations, and by the time I spotted the uneven tread wear the rotations were over do. It was too late.

Maybe I have the wrong member, but I thought you once claimed you had an avg of over 57 avg MPG for one tank and had displayed the picture of your dashboard reflecting that.

I follow some of your advise, but I'm already at almost the max of the tire company's recommendations, and by past mistakes I do fear going over the 44 it claims is MAX. I pump 40ppsi and in warm days, long trips the pressure might get close to 43ppsi. That's as high as I feel is good for my tires, and I can tell these corners become much harder to cling on too at higher tire pressures, and in eastern Kentucky one has curves everywhere they drive.

I don't like to reset my MPG Avg computer. I know how to do it, but I choose to leave it alone and calculate ALL of my driving and average it up. I'm still at 45.4 MAX, and that is what I parked it at in the driveway. I have to do A LOT of EOC, even for short distances, and if it's rush hour at a long red light (we have one that takes 5 minutes in rush hours!) I will turn my engine off but pay plenty of attention so I have it started at the moment the light turns green. I only do this for the lights that make me wait more than 2 minutes.

I hope my first oil change will help to improve my MPG. Also I am already due to rotate my tires, and I really wish I had a hydraulic jack instead of what chevy puts in the trunk of these cars. I have YET to understand how on earth to even unfold the jack and lug-nut wrench that came with the doughnut tire.

I'm too lazy tonight, what is DWL again?

About shifting, I have drove manuals since I got my first 125cc motorcycle at 14 years of age. I dislike automatics for the many advantages I get out of manuals. However I wish these cars came with a 6th gear! The way my car is geared I change the gears very fast from 1 to 5th, and I hate to take the RPMS very much above 2,2500 even when escalating speed.

I very much plan on getting over 50 avg MPG, but when I do it will have to be for the entire average, not just one tank. I feel the more miles driven the more accurate that average will be, if one does not re-set it.

I have very much got the hang of this EOC stuff. It's pretty cool, I bet I coast for two solid miles until I pull right into my driveway and turn the lights off! I do this everywhere now. Just about any place I go, I find a way of coasting in and parking with the engine off.

Because of my schedule I have found myself doing a lot of late night driving that seems to be a magnet for police radar guns. I live in an area where most people that are lucky enough to score a job here, work first shift. 2nd and 3rd shifts are fairly rare in these parts, so the police seem to act as if everyone on the road is a suspect after 10:00 pm. I can not thank my radar detector enough because on numerous occasions recently I have been driving below 45 in a 55 zone and pick up radar from clear down the road which I use as a cue to bump start and get to the P.S. Slow drivers do not get many chances after dark here, they are on a constant hunt for intoxicated drivers at night time. I do not believe they are busting too many though because everyone here knows they risk a sobriety road block at any time of night or day here. So far all such checks have been between the hours of 7:00pm and 1:00Am. So I'm often out during this same time period trying to perfect mostly driving in EOC and bump starting, and so far it's becoming second nature for me. However, I honestly believe most of the local police hear recognize my car by now. Heck I have even been motioned through sobriety checks without even rolling my window down while it seemed all the others were being stopped. Something about my car stands out in a crowd, and I suspect it is my cb antenna and bright GPS I travel with everywhere. Most people in small cars here do not have theirs set up like mine. So that's sort of a good feeling.

My best to you and your high MPGs! I'll be playing catch up for awhile you can be sure!

[elhigh]

That's crazy-great mileage. For years and years the party line was that American builders don't give two cents for fuel mileage.

50+ mpg in an American car? Fantastic.

[Fr3AkAzOiD]

Originally Posted by Jammer

Maybe I have the wrong member, but I thought you once claimed you had an avg of over 57 avg MPG for one tank and had displayed the picture of your dashboard reflecting that.

That was for one round trip (70 miles) not a complete tank. That tank ended up at like 50.5 mpg.


I reset my mpg meter every tank due to the more miles you have the more it takes to change your average.

I just follow my averages through my gas log through this site.

Efficiency log for: Cobalt XFE - 2008 Chevrolet Cobalt XFE

Lifetime Fuel Economy: 40.86
90-day Fuel Economy: 48.65
3-tank Fuel Economy: 51.32
EPA Rating (% over): 29 (67.7586%)
Total fills: 62
Average cost per gallon: $2.60
Average cost per fill: $25.33
Average cost per mile: $0.06 Total gallons used: 744.8
Total miles traveled: 30435.2
Total cost: $1936.47
Total saved: 304.69 gallons
Total saved: $792.19
Average tank distance: 490.89


My lifetime average is so low due to giving up hypermiling during the winter and getting mid 30's numbers. If I had continued I probably would have mid/upper 40's as my average so in that respect I'm catching up to you Jammer.

[Jammer]

Originally Posted by elhigh

That's crazy-great mileage. For years and years the party line was that American builders don't give two cents for fuel mileage.

50+ mpg in an American car? Fantastic.

GM has had good gas mileage on their mid-size cars for many years. It is true they have more cars that get over 30 MPG than Toyota or Honda. However they have a poor record with sub-compacts, which of course is where the higher MPG often come from. Take their Pontiac 2 seater Fiero- from the 1980's it got MAYBE 25MPG at best. The Chevette got maybe 20- to 25 MPG, based on the 1977 model I used to own. These were VERY SMALL CARS! Shucks even my previous 2005 MED-SIZE Colorado (Keep in mind this truck is SMALLER than a SILVERADO) claimed an EPA of 20 MPG Highway, but in 2-wheel drive mode my math showed it was getting around 17MPG, in 4-Wheel drive I hesitate to even think about it. With their pickups there does not seem to be much of a gap between full size and med-size in terms of MPG.

I have yet to reset my gauge, but I bet if I did AND drove just right I could get over 50 avg MPG. My AVG MPG is based on the long term and it's 45.4 AVG MPG and many people claim these cars peak out at over 10,000 miles in terms of best AVG MPG, others claim the first oil change improves the avg MPG. If this is true, then I'm just behind Fr3AkAzOiD at 45.4 AVG MPG - FOR A TOTAL SINCE I FIRST BOUGHT MY CAR NEW.

It all boils down to how you drive these cars. When I bought my car from the dealership the car had been drove about 130 miles because I bought it from a dealership I knew well and trusted and they had to get the car I wanted from a dealer out of state and drive it back. WHEN I FIRST GOT INTO MY CAR IT HAD 25 AVG MPG on it! And now I am getting ALMOST double that. I feel it boils down to the car being fully broken in AND driven correctly. If you want to hot rode these cars they will do about as good as any other average car on the road, perhaps even better than some. But if you wish to save your money these cars reward you back for good driving habits. I bet a good 40% of my drive-time is spent in Neutral!

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.