Gas Mileage

[Beezer]

First post.
Sorry to dig up an old post but I'm not seeing anywhere near the mpg some of you are posting. I drive probably 90% highway (commute is roughly 100 miles round trip) doing about 65-70mph using my cruise control when possible and only see about 28mpg. I have a 2012 LTZ Auto hatchback which has 26k miles on it. I could easily get 35-40mpg in my 2008 Ford Focus which I ended up putting 150k miles on it.
What could be going on?

 

[mitdr774]

Many things can affect economy. What are the exact conditions of your commute? Something is really off if you are only pulling 28 on the highway.

 

[sx sonic]

First post.
Sorry to dig up an old post but I'm not seeing anywhere near the mpg some of you are posting. I drive probably 90% highway (commute is roughly 100 miles round trip) doing about 65-70mph using my cruise control when possible and only see about 28mpg. I have a 2012 LTZ Auto hatchback which has 26k miles on it. I could easily get 35-40mpg in my 2008 Ford Focus which I ended up putting 150k miles on it.
What could be going on?

Check the link in my signature.

 

[readytogo!]

I drive about 90% highway also and I cant seem to get over 28 average hand calculated now and that is driving normal with a k&n Intake, tune, slp catback , royal purple, and ttr mounts.... I don't understand it

 

[sx sonic]

What's the temp in your area? Is that 10% city driving stop and go? Do you idle the car much? What's your a/c habits? Do you cost to stops or let off the gas shortly before you get on the brakes?

What's your tire psi? How far do you go between oil changes?

All these can have a huge impact on fuel economy. All of this is covered in more detail in the MPG master thread.

 

[readytogo!]

upper 70's, its very little stop and go, never idle the car when I don't have to, a/c o until its cool enough then off, I coast to stops, my psi is at about 36 its rec. 35.
I run royal purple and change it every 4000 miles and actually changed it right before I first posted.

1.8 auto hatchback

 

[mitdr774]

What speed do you run on the highway? At the speeds I run at, A/C on will result in about a 4-6MPG reduction in economy. I also run my tires at 40 PSI. It helps with several things, one of them being economy.

 

[barch88]

I run about 77 average on expressway, i get about 30mpg

 

[mitdr774]

Be hard pressed to hit the EPA highway rating at those speeds.

 

[readytogo!]

I run anywhere from 66-68 or so, I hardly ever go very fast on the highway, that's why I cannot understand such low mpg, and I also don't use 87 I use 89 with no ethanol and im still getting such low numbers . I also bought the belly pan and installed it a few months back with no increase in mpg

 

[mitdr774]

Just so you know, the EPA highway cycle has a maximum speed of 60 MPH and an average speed of about 48.5 MPH. 60 is about the slowest I will go on the highway (55 is the minimum legal speed on the interstate in Mi.) but steady state driving in the 45-50 range is far more efficient than even 60. The faster you go, the worse the economy will be.

If I set my cruise at 60 I can pull off mid 40s, bump it up to 70 and my economy will drop to mid 30s. If you add in A/C or windows down and it drops to low 30s. This is with a pure highway run.

 

[Chevrolet Customer Care]

Hi Beezer,

Here is another link that may be helpful.

FuelEconomy.gov

If you make the changes suggested by the links and comments provided and are still not getting the expected MPG please feel free to send me a private message and we cal look into this further.

Jackie
Chevrolet Customer Care

 

[readytogo!]

I don't even drive 70 mph though and I cant even touch 30 mpg anymore idk why..i take off slow
And to compare to your numbers at 60 I will get a max of 36.5 or so per DIC and at 65 I will get 29-31 that's awful especially considering all of my mods

 

[mitdr774]

First problem is using the DIC. Hand calculate and then see what your numbers are like. What are your mods?

 

[barch88]

Be hard pressed to hit the EPA highway rating at those speeds.

I don't want to hit EPA highway ratings, don't expect to, haha. Once I get my tune file completed from Trifecta (should be this weekend), my MPG is going to probably increase 1-2mpg

ill be looking at 30-32+ mpg at nearly 80mph, not bad!!! If i drive like a granny I can probably push well past EPA ratings with all of my mods

 

[mitdr774]

I get better economy with a stock tune and parts installed than with the trifecta tune and the same parts installed. Are you actually having decent results dealing with them? I am not.

 

[barch88]

It's still great MPG to me, I spend maybe $140 a month on fuel and travel probably 1000-1200 miles a month. Going from nearly $100 per fill up to $30-$40 per fill up this is awesome.

 

[readytogo!]

Like I said before, I have hand-calculated every single tank since I bought the car in January. I was only meaning that I went by the DIC while actually in motion.

My mods are, k&n SRI, TTR engine and trans mount,trifecta tune, slp catback exhaust with reso and muffler.

 

[savegejon123]

I changed my oil and went up 10mpg. Got to 40mpg for a few days.

 

[readytogo!]

I just filled up and on this last tank I switched back to the stock tune to see if it would make a difference and im definitely disappointed. Babying the car the entire tank always shifting at 2k or lower and driving 90/10 highway city. I never went above the speed limit(65mph) and I coasted to stops. All of that effort and I came out with a measly 31.5 mpg hand calculated.