[atc108]

I get my new 2.4L FWD Terrain SLE two weeks ago. Now it's around 350 miles but the average MPG is only 21.0. I drive half Hwy and half city so I think it should be 24 or more.
Is that because of it's a NEW car or my driving habit? Could it do better after few months?

Thanks.

 

[gar187er]

new car syndrome....wait till you break it in.....search around, everyone has this issue

 

[RSchleder]

I agree, these direct injected engines need several thousand miles to totally break-in. My V6 awd Terrain with 11,000 miles recently got 23.7 mpg on a 1300 mile interstate highway trip. Just give it some time/miles and it should improve both mpg and performance.

 

[Terra-Nox]

In addition to break-in period warmer temps of spring should help also, even more if you live where they take out the ethanol in summer.

May take some effort but if better MPG average is your goal you can figure out sweet spots for better milage using tach and instant economy (although the instant economy seems to vary quite widely compared to other vehicles I have).

In my case we have had the Terrain for a week and after a couple road trips on the weekend I am just a tad under 600 miles on the ODO with a D.I.C. average milage sitting at 21.3 with the 6cyl AWD. This is with careful driving on my part (not really hypermileing, just careful).

My experiance with other GM vehicles yields me the best milage with tach running close to 1500RPM for the 6CYL ( for my 4CYL around 1900~~>2100 is best).

I have used this as a starting point for now to see how it goes and so far 40MPH and 55-60 MPH seem to work pretty well to reach this point.

This is just my experiance and yours of course will vary

 

[fireman591]

Check your oil for fuel contamination ASAP. You are getting the numbers I had when mine was new. It turned out that the high pressure fuel pump was bad. It goes into the dealer today for a new pump. The bad news is fuel is a bad lubricant. I won't know how much damaged was caused to the engine with sheared down oil during the break in period.
Keep us posted and don't wait to long. I made the mistake of listening to advice like "wait till you get 10000 miles on the clock" and "the smell of fuel in the oil is normal for a direct injection engine"
The HP fuel pump is cam driven. The seal fails and fuel gets into the oil. It also evaporates so you may or may not notice an increased amount of oil when you drive it. Mine is up a little with 500 miles since the last oil change. Not good
let us know what you find out

 

[atc108]

Check your oil for fuel contamination ASAP. You are getting the numbers I had when mine was new. It turned out that the high pressure fuel pump was bad. It goes into the dealer today for a new pump. The bad news is fuel is a bad lubricant. I won't know how much damaged was caused to the engine with sheared down oil during the break in period.
Keep us posted and don't wait to long. I made the mistake of listening to advice like "wait till you get 10000 miles on the clock" and "the smell of fuel in the oil is normal for a direct injection engine"
The HP fuel pump is cam driven. The seal fails and fuel gets into the oil. It also evaporates so you may or may not notice an increased amount of oil when you drive it. Mine is up a little with 500 miles since the last oil change. Not good
let us know what you find out

Thanks. Thus could you tell me how to check my oil in this case?
I'm still a beginner....

 

[fireman591]

Thanks. Thus could you tell me how to check my oil in this case?
I'm still a beginner....

If the contamination was as bad as mine you can smell it on the dipstick. The oil will also seem very thinned out. Almost like black water.

 

[MACATOWA]

Here are so stats on mpg from a year ago when my 10' Nox AWD was brand new;

first tank 450 miles 25 mpg 40/60 split early March 10
second tank 26.88 30/70 split
third tank @ 1254 miles = 451.7 miles = 28.5 mpg 30/70
forth tank @ 1614 miles = 25.33 mpg
1801 miles = 27.2
2455 miles = 26.53
5500 miles = 26.38
7650 miles = 25.93
8690 miles = 28.09
10050 miles = 28.01
12800 miles = 25.88 July

Break-in did not seem that important in my case.
I did switch to Mobil 1 at the first oil change at 2800 miles and have run it ever since. I'm at 32,500 miles now.

 

[Alberta_Girl]

My 2011 Terrain (3.0 L V6 AWD) has nearly 5000 kms on it (3000 miles) and I consistently get no more than 22 MPG and my daily commute is 2/3 highway driving each way. In the vehicle instrumentation thingy on the dash, it consistently ALWAYS indicates that my average fuel economy is 12.9 L/100km. It never ever wavers from this (once was 12.8). At $80 a pop to fill up the tank, I need a part time job just to afford fuel. I'm hoping that it's true that once the engine has broken in, fuel economy will improve.....and at least be somewhat closer to what this vehicle is advertised at getting in terms of fuel economy.

 

[Terra-Nox]

Hhmm the EPA rating here in the states for the AWD 6 is 22MPG for highway. Judgeing by that is seems you are doing well. We have had ours for just a week and in careful driving it seems finding a speed/gear that has the tach running around 1500 works pretty well (can't always do that of course). 40MPH and 55-60MPH seem to work well for that (at least on ours). Warmer weather is on its way eventually and that should help also.

 

[RIT333]

Hhmm the EPA rating here in the states for the AWD 6 is 22MPG for highway.

I thought it was 24 MPG highway for the AWD-6. I could be wrong though.

 

[Terra-Nox]

I thought it was 24 MPG highway for the AWD-6. I could be wrong though.

24 was last years number if I remember ciorrectly.
This is from GMC's website:
AWD Models 3.0L V6 SIDI (Spark Ignition Direct Injection) 16/22 MPG 20

 

[INNOCNT]

My 2011 Terrain (3.0 L V6 AWD) has nearly 5000 kms on it (3000 miles) and I consistently get no more than 22 MPG and my daily commute is 2/3 highway driving each way. In the vehicle instrumentation thingy on the dash, it consistently ALWAYS indicates that my average fuel economy is 12.9 L/100km. It never ever wavers from this (once was 12.8). At $80 a pop to fill up the tank, I need a part time job just to afford fuel. I'm hoping that it's true that once the engine has broken in, fuel economy will improve.....and at least be somewhat closer to what this vehicle is advertised at getting in terms of fuel economy.

That's about right I would say, it was -30C here this morning, not sure how cold it was where you are but for winter running 12.8/12.9 L/100 or 22/21 mpg - that's to be expected. Once summer hits you'll see a good improvement. I get 27-28 mpg in the warmer months, depending on my foot position of course. [/color]

Hhmm the EPA rating here in the states for the AWD 6 is 22MPG for highway. Judgeing by that is seems you are doing well. We have had ours for just a week and in careful driving it seems finding a speed/gear that has the tach running around 1500 works pretty well (can't always do that of course). 40MPH and 55-60MPH seem to work well for that (at least on ours). Warmer weather is on its way eventually and that should help also.

Yep for sure, that would calculate out to our 26-27 mpg (Imperial) as your gallon in the States is smaller than ours.
22mpg US is equal to 22miles/3.79 liters, which works out to 10.76 liters/100km's or 62.5 miles.
Which is 26.3 mpg (imperial) [/color]

 

[Alberta_Girl]

That's about right I would say, it was -30C here this morning, not sure how cold it was where you are but for winter running 12.8/12.9 L/100 or 22/21 mpg - that's to be expected. Once summer hits you'll see a good improvement. I get 27-28 mpg in the warmer months, depending on my foot position of course. [/color]


Yep for sure, that would calculate out to our 26-27 mpg (Imperial) as your gallon in the States is smaller than ours.
22mpg US is equal to 22miles/3.79 liters, which works out to 10.76 liters/100km's or 62.5 miles.
Which is 26.3 mpg (imperial) [/color]

Oh that's great to know, that it should be better once we're out of the deep freeze Thanks.

 

[INNOCNT]

24 was last years number if I remember ciorrectly.
This is from GMC's website:
AWD Models 3.0L V6 SIDI (Spark Ignition Direct Injection) 16/22 MPG 20

I thought it was 24 MPG highway for the AWD-6. I could be wrong though.

This is off the delivery window sticker from my 2011 Terrain SLT-2 AWD V6.
I don't think I'll be hitting that number on the far right anytime soon!! lol [/color]

 

[Alberta_Girl]

This is off the delivery window sticker from my 2011 Terrain SLT-2 AWD V6.
I don't think I'll be hitting that number on the far right anytime soon!! lol [/color]

NO kidding. Same sticker on mine. So what's up with that? How can they over-inflate the fuel economy like that and get away with it? Isn't that false advertising? Do their 'great numbers' come from testing done in absolutely pristine and ideal conditions?

 

[Terra-Nox]

Do their 'great numbers' come from testing done in absolutely pristine and ideal conditions?

Yes it would seem so
I believe here in the states the manufacture does the tests based on parameters from the EPA (and the EPA does their own on a random basis) so the results are what they are.

 

[scottb]

i was just reading that highway epa is tested at 48 mph...no wonder they get so high...

 

[Denali AWD]

This is off the delivery window sticker from my 2011 Terrain SLT-2 AWD V6.
I don't think I'll be hitting that number on the far right anytime soon!! lol [/color]

That's a crazy number. My V6 FWD is rated 24 mpg highway. Apparently something got lost in the conversion from liters to gallons.

 

[Black Rain]

In Canada, car manufacturers advertising MPG use the Imperial gallon, which gives a much better looking number.

1 Imperial gallon = 4.55L

1 U.S. gallon = 3.79L

I assume that the DIC in the vehicle reports in US gal.