Mileage: getting the best out of your Sonic

[pounamu]

Hi everyone,

I've had my Sonic for a week. and in mostly city driving I get (wait for it, cause it's painful): 17mpg. It's not a typo. SEVENTEEN.

So I'm hoping to get some feedback and advice from you guys about getting better mileage out of my new (supposedly fuel efficient) car. Like I said, I do mostly city driving, some traffic but nothing horrendous. Some of you will probably say that I need to "break in" the engine, which I've heard before, and I'd love to hear the rationale behind that statement. If you tell me that I need to wait 5K or more to get advertised mileage, that's almost a year of work related commuting for me - WAY too long. And to be honest, I think we as consumers really need to have a problem with the fact that a product we buy because of high mpg claims needs to be broken in for extended periods before it can be used as advertised.

I also realize that a lot of mpg success stems from the right driving habits, so please, I'd love for you to share your tips about the proper driving habits (I know about not breaking hard and not accelerating too rapidly, for example). I'd appreciate any kind of insight, because frankly, 17mpg is beyond shameful.

 

[davecerv]

Hello!
Woaa 17mpg… I'm assuming you have an auto sonic.
First, the number has been from hand calculating a full tank or is that the number you see on the screen?
If you're mostly doing city then that has a lot to do with it, especially right now.
How is the weather where you're at? (cold weather affects mpg)

I remember when I barely got my sonic (at 10 miles) the screen said I had 16mpg. I was like waaaaa what have I done… But it did get better. I find myself actually getting the EPA estimates on my sonic. I'm currently at 5,987 miles. This car is good to me on the highway.

 

[Maddog2020]

This new thread had some good information if you haven't seen it.

http://www.sonicownersforum.com/forum/mpg-discussion/9460-mpg-master-thread-mpg-tips-questions-explanation-concerns-here.html

17 MPG is not good. What city are you driving in?

 

[pounamu]

Thanks for the great responses guys!!

Yes, mine is a turbo automatic. So I know it will be a bit lower than a manual, but 17 is really pushing it!

i'm looking at that thread now, thank you! so helpful. Right off the bat, my tires were low in pressure (32 instead of the recommended 38, the car most likely sat on the lot a while and the tires got soft). I fixed that on Saturday, so now they're all set. I'm guessing that affected the mileage. Weather wise, it's been gorgeous and warm here, and the AC / heater was barely on. I drive about 30-40 minutes one way (about 12 miles), so it's not a super short trip, and I average about 30 m/h with some stops and traffic. Definitely some stop and go. I'm going to train myself to coast to stops better (still learning the feel of the new car).

This is a good start - any more input is highly appreciated!

PS Maddog, that pup in your avatar is adorable!

 

[Maddog2020]

Thanks, I just wish I could get him to stop smoking!

 

[sx sonic]

Bummer on the low MPG.

I'm seeing a few things that are killing your fuel economy.

Kinda short trips with average commute times. Your commute works out to about .4 miles a minute. That sounds like a lot of stops or a good amount of sitting, neither is good for gas mileage.

Your stating it'll take about a year to turn 5k miles. That tells me you do alot of short trips which hurts mpg.

Low miles on the engine. Break in is a legitimate thing, after a few thousand miles a car will be getting It's best gas mileage. It has to do with the hundreds, maybe thousands of contacting surfaces wearing into each other and then sealing/seating better, getting a smoother & slicker surface, and/or mating better. Essentially internal friction gets reduced as the engine breaks in.

Also the ECM adjusts fuel trims and other parameters for best economy and power. It takes a few hundred miles for it to adjust for all the variables of a particular engine. Just the way it is, even Ferrari, Cadillac, and F1 engines go thru the same break in.


My advice is reset the DIC before you leave for work and see what it says after a few days. Then work on your driving habits to maximize your mpg.

 

[Xecutionr]

wow.... i get 25 at the lowest with my performance tune on and 40mpg at the highest when stock tune is on...

 

[pounamu]

Maddog, the cute ones always get away with everything

SX Sonic, thank you so much for the explanation. It certainly makes sense. I'll reset things when I go to refuel tomorrow and will keep an eye on things. Overall I think the mpg is improving a bit, at least according to the onstar computer evaluation. I'm looking forward to things improving in the months to come.

 

[bob67]

I have a 2012 1.8 auto hatch with 20K and i drive conservatively mostly 40-50mph roads , and i get max 30mpg...

 

[Chevrolet Customer Care]

Hey pounamu,

Here is a website with helpful tips to improve MPH;

Driving More Efficiently

Let me know if you try these suggestions and your MPG does not improve. I will look into this further. Just send me a private message.

Jackie
Chevrolet Customer Care

 

[pounamu]

Thank you Jackie, will do!

 

[Stew]

Just one more tidbit on break-in, it's not just the engine that is polishing it's surfaces. Everything that rotates goes through this to some degree, wheel bearings, transmission, brake pads and/or shoes which may have a tight fit when new depending on their adjustment, and of course the engine. Add all those little things up and they do matter.

Another thing that's been discussed is what octane gas you're using, I know, there is another thread debating on if this makes a difference in mpg, but let me just say that I used 87 octane up until a couple months ago and I swear that (in my case at least) my mpg has increased using 92.

Yeah, there is the cost difference but the improvement in mpg makes it a wash so why not use higher octane and get a little more powa? I run my tires at 40 psi but may increase that up to the sidewall max, I haven't decided yet, and no it doesn't wear out the center of your tires doing that.

My Tread Depth Log at Max Sidewall Pressure

 

[Eric Smit]

I usually say slow down on these kind of threads, but at 30 I'd say you beat me to it. sx sonic naked my point, which I'd like to reiterate. .4 miles a minute is pretty slow, and since your said city I'm guessing you spend a lot of time varying speeds. I find my best MPG at 35 in sixth gear, usually around 85.

 

[Xecutionr]

I was cruising backroads (hills and turns) around 70-80 on my stock tune getting 40mpg not joking it surprised the hell out of me. This just happened the other day


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[pounamu]

Thanks guys. An update: the mpg was creeping up about a point a week, so that last week I found the car was getting 20mpg (everything remained the same, habit and trip-wise). So definitely great points about the car needing to get into the groove, so to speak. Then last Friday I went on a 300 mile highway trip to the Berkshires, doing about 65 on average, and I saw the mpg increase significantly during the trip (hard to say what I was making at the time, guessing low 30s?) So now thanks to that trip, the overall mpg went up to 25. I'll keep an eye on it, hoping things will continue to improve. I have to say, that overall the handling of the car has improved a lot - things just seem smoother somehow, including handling and the brakes especially. Somehow things got a lot better after that recent highway trip, handling and breaking-wise. Oh, and I also made sure not to exceed 2500 rpm - mostly doing 1800-2000. It's easier to do that on the highway; I still have to get a good grip on taking off under 2500rpm in city driving, when I'm trying to beat the lights.

 

[PolkSDA]

Bummer on the low MPG.

I'm seeing a few things that are killing your fuel economy.

Kinda short trips with average commute times. Your commute works out to about .4 miles a minute. That sounds like a lot of stops or a good amount of sitting, neither is good for gas mileage.

Your stating it'll take about a year to turn 5k miles. That tells me you do alot of short trips which hurts mpg.

Low miles on the engine. Break in is a legitimate thing, after a few thousand miles a car will be getting It's best gas mileage. It has to do with the hundreds, maybe thousands of contacting surfaces wearing into each other and then sealing/seating better, getting a smoother & slicker surface, and/or mating better. Essentially internal friction gets reduced as the engine breaks in.

Just as another point of reference, my situation is almost identical to the OP:

LT 1.4 Turbo automatic
Just turned 600 miles, so well within the break-in period
Almost entirely city driving, with trips of short durations (my commute to work is 11 minutes; my average annual driving is 5500-6000 miles).

That said, either my car was "tighter" out of the gate, or my driving habits are more laid back. My first full tank of 87 octane I got 25.1 mpg, right on the money as far as the window sticker. My second tank I got 24.9... on 91 octane, go figure. (Both figures hand calculated, but within .2 of the in-dash mpg calculator.)

So his initial numbers sound abysmally low to me.

 

[hand amputation]

FWIW, when I got my Sonic, my MPG hovered at around 20-22 for the first couple weeks.

Fast forward to just hitting 2K miles, it stays around 31.1.

TL;DR: It'll go up.

 

[talldude67]

WOW! DOSENT SOUND GOOD THERE. HAVE HAD MY '13 5DR HATCH A MONTH NOW AND THE BEST MPG IS 41.3 ON STEADY CRUISE INTERCHANGE, JUST TURNING 735mi.