[davidtranlds]

Hi guys

So, recently purchased Holden Cruze 2012 SRi-V JH Series II, 1.4L turbo petrol, second hand.

It's advertised to have a combined fuel economy of 6.9L/100km (34mpg)

However, it's currently running at 10L/100km

The car itself drives smooth (except when shifting gears - details will be in another thread), no misfiring (that I can hear), pinging, knocking, etc.

Wheels are pumped to the right pressure, brakes aren't dragging, I mostly do highway/freeway drives, which range from 70km/h to 100km/h (44mph to 60mph).

Been like that since the day I got it.

Any ideas what I can diagnose to see what could be causing it to eat so much fuel?

Thanks

 

[bibu16v]

Manufacturer advertising fuel economy is one thing reality is another one ...
For better fuel economy(especially for a used car newly purchased):

• fresh air filter;
• fresh engine oil & filter;
• fresh spark plugs(for a petrol engine);
• do not use A/C permanently(in cold time especially);
• avoid short trips (under 5-7 miles, especially in cold time);
• avoid using low octane petrol;
• check O2 sensors;
• check wheels alignement...

It could be others too...

 

[grs1961]

Various things can have an effect, as pointed out above, but if you're in Darwin or FNQ it probably won't get 6.9 downhill with a tailwind and a stick of ginger shoved up its jacksie.

That said, which fuel are you putting into it? The 1.4 doesn't like standard unleaded, it is much happier on 95, and, of course, positively blissed-out on 98[1].

And, of course, driving style is the dominant factor. Do you get it up speed and then engage the cruise control, or do you let you foot do the talking??

Oh, and welcome to another Aussie, be aware that a lot of what you read on this site really only suits the US-built Cruze, not Korean- or Oz-built models.

1 - Australian Octane Ratings are not the same as those in the USA.

 

[Johnny B]

Clean the MAF sensor. You really need an obd tool, if your car ever misfires to the point you can "feel it" you have big problems. Change the plugs. Check the response time on the O2 sensor.

 

[JLL]

So does mine! But for different reasons than yours.

 

[davidtranlds]

Thanks everyone - I'll check out the air filter and MAF sensor before my next service.
I have a service due soon, so I'll let the mechanic work on the spark plugs, engine oil & filter.

I do have an ODB and in a different post, I asked whether anyone might have had a list of what standard readings I should be getting are, so I can compare and see if anything's off, but it probably got missed lol.
Can't seem to find it online, but could just be looking wrong...
Anyone got that list?

As for driving, I try to use cruise control as often as possible.
I don't have a heavy foot, I take it nice and easy.
I'll accelerate up to the limit and resume cruise. Sometimes I resume cruise early and let it accelerate up to the speed set.

Generally speaking, conservative driver - all about fuel economy.

First refill I used Unleaded 95. Current refill (2nd) I'm using 91.
Both sitting an average of 10L/100km

I might stick to 91 for the time being, just due to finance... Once the service is done and fuel economy is up again, I'll try some 95's to see how that goes.

 

[arose513]

I would also maybe look into some additives by Liquid Moly. Just to clean out what's going on in the inside. I work/sell Liquid Moly and have only had good experiences.

Additives

www.liqui-moly.com

 

[Johnny B]

Anyone got that list?

With the car fully warmed up and all accessories off....
1.9 grams/second = idle
4.0 grams/second = 2000 rpm
18 grams/second = 100 kph

 

[snowwy66]

Check compression when changing plugs.

 

[davidtranlds]

With the car fully warmed up and all accessories off....
1.9 grams/second = idle
4.0 grams/second = 2000 rpm
18 grams/second = 100 kph

Thanks for that Johnny

I'll see if I can decipher all that in the cheapo OBD I got lol


I also noticed something today - when decelerating (whether using breaks or just foot off the gas), I noticed Fuel System 1 has OL Drive, which I understand when I WOT or accelerate hard will have OL Drive, but is it normal during deceleration also?

STFT will jump to 40-50% temporarily during deceleration.

 

[Johnny B]

noticed Fuel System 1 has OL Drive,

I'm pretty sure what you are seeing is the fuel cutout. Aka, DFCO.

Also, IMHO, unless you're a tuning guru trying to cipher stft is basically impossible. Ltft is what counts.

 

[ChevyGuy]

However, it's currently running at 10L/100km

That's 23.5 MPG. If you're mostly in-town, 25 MPH (40 Km/h), with frequent stop lights/signs, that's quite reasonable. If you're spending it on highway/freeway, that's really low.

I find the EPA's definition of "city" to be laughable.

Depending how where you're driving it, there may be nothing wrong at all.

 

[davidtranlds]

So my average MAF readings on

Idle: 1.9
2000rpm (while stationary): 4.4
100km/h: ranges between 16 to 22. Need to do nore testing, find a flatter, longer road with less traffic

As for the 10L/100km, I'm mostly on highways (70-80) and freeways (100) getting to work and home
A few lights here and there between

I don't do much city/suburban driving, mostly on Sunday only

I've since gotten it down to 9L/100km

Still 2L more than the rated 7L combined.
I understand these are never something to go by, all market BS, but 2L more is still quite a bit, particularly after the amount of driving I've done

I've even reset the average so I can get freah readings of me purposely on the freeway, so I don't have slower city data in there

 

[skildude]

If the previous owner used bad lower octane gas, You are likely to get the CAT filled with gunk. One sign of this is the engine bogs down going up hills, or won't accelerate up hills. There are gas additives for this but you may end up needing a new CAT. When I put a new CAT on the mechanic told me to only use Premium Octane and Top Tier fuels. In the US top tier fuel has additives to clean your ports and engines combustion chambers. Your friend at Chubs bait and fuel stop will likely not have top tier gas.
Another problem is the Injectors. They will get fouled up if bad gas is used. A trick to help this is carb/Injector cleaner in the throttle body when the vehicle is off. reattach the Air Hose and start the vehicle. This will get the carb/injector cleaner directly into the injectors. It will run rough for a few seconds but it will be cleaner when you are done.

 

[kenm4670]

Clean the MAF sensor. You really need an obd tool, if your car ever misfires to the point you can "feel it" you have big problems. Change the plugs. Check the response time on the O2 sensor.

Temp and humidity can also affect mpg.

 

[Johnny B]

Temp and humidity can also affect mpg.

Is that right. Huh. So if I'm looking to get more mpgs do I need to raise or lower them?

 

[Aussie]

I have a 2012 diesel and mostly do really short trips and 10L/100km is what I get around the suburbs. All the 50 kph roads around here are a fuel economy killer. I do drive with my automatic a/c on all the time, so that may cost me a little. Do you check your fuel consumption by measuring the distance travelled at each fillip, and checking the fuel used? This is the most accurate measure as the DIC can mislead you as to how much fuel you actually use. By the way 6th gear won't engage under 100kph and my car mostly doesn't go past 4th. Maybe you should check what gear your car uses at 70 kph?

 

[davidtranlds]

I double check my consumption by checking distance against fuel used also, definitely guzzling.

I haven't noticed it bogging down going up hills, haven't gone through many.
I have noticed though that when I'm trying to accelerate, say 80 to 100, even though I'm only accelerating lightly, only need to casually increase speed, car likes to downshift, accelerate to the speed I want, then upshift again.
And it does go to 6th at under 100km/h.
I think it usually goes to 6 around 70-80 already, have to check again, but it does shift up to 6th before 100km/h

 

[pcheffernan]

Hi guys

So, recently purchased Holden Cruze 2012 SRi-V JH Series II, 1.4L turbo petrol, second hand.

It's advertised to have a combined fuel economy of 6.9L/100km (34mpg)

However, it's currently running at 10L/100km

The car itself drives smooth (except when shifting gears - details will be in another thread), no misfiring (that I can hear), pinging, knocking, etc.

Wheels are pumped to the right pressure, brakes aren't dragging, I mostly do highway/freeway drives, which range from 70km/h to 100km/h (44mph to 60mph).

Been like that since the day I got it.

Any ideas what I can diagnose to see what could be causing it to eat so much fuel?

Thanks

What bibu.gm suggested are all great ideas. I want to point out a few things that may not have been mentioned. No one sells a perfectly good running car (most of the time). Usually there are issues, some small, some large. If you did not receive the maintenance documentation on the vehicle, you should assume "Nothing has been done" and start from scratch getting all the maintenance caught up on what should have been done at certain intervals as explained by your GM owners manual. Secondly, gasoline is not gasoline. You cannot put cheap gas in that engine. It calls for "Top Tier Gasoline" which has the additives necessary to keep it running clean and achieve your best fuel economy. For more information see TOP TIER™ Gasoline Brands You can run 87 octane through that vehicle but it must be Top Tier or you will have issues in the future.

 

[Jhon]

Hi guys So, recently purchased Holden Cruze 2012 SRi-V JH Series II, 1.4L turbo petrol, second hand. It's advertised to have a combined fuel economy of 6.9L/100km (34mpg) However, it's currently running at 10L/100km The car itself drives smooth (except when shifting gears - details will be in another thread), no misfiring (that I can hear), pinging, knocking, etc. Wheels are pumped to the right pressure, brakes aren't dragging, I mostly do highway/freeway drives, which range from 70km/h to 100km/h (44mph to 60mph). Been like that since the day I got it. Any ideas what I can diagnose to see what could be causing it to eat so much fuel? Thanks

Since you recently acquired the car you must do the following: change the spark plugs, put them original, change the engine air filter, clean the sensors, the maf sensor and the flow sensor that is near the air filter ... you can do that yourself, whenever you are going to do it, disconnect the negative from the battery and always put 95 octane gasoline on it because that car is turbocharged. I am giving you all these recommendations because when I bought my Chevy Cruze, which is also a 1.4 turbo, I had the same situation as you. With this, consumption will be greatly reduced....never expect that this car will give you the performance that the manufacturer says since it is a very heavy car...this car weighs about 450 pounds more than the 2016 chevy cruze that has a lighter bodywork and that is why the model that follows it is economical.