Warning. Never run less than 89 octane in the turbo.

[dannyg]

I also have a 2014 Cruze with the 1.8 normally aspirated (LUW) engine. Any advantage there to the higher test stuff?

I'll let you turbo guys discuss turbo issues, here's my experience with the 1.8L:

For my 1.8L 5sp LS Sonic, I tried running three tanks of 91 in a row. I saw no difference in MPG, so I'm running 87 with the 1.8L. No issues.

Note that I live in the northeast (bought the car in Maine, now live in New York), I rarely use AC, not at all like the conditions in the Edmunds article.

But try 2-3 tankfulls of 91 in your Cruze, see what happens!

 

[Blue Moon Sonic]

Since I've now been sufficiently schooled I will ask this. I also have a 2014 Cruze with the 1.8 normally aspirated (LUW) engine. Any advantage there to the higher test stuff?

I'll let you turbo guys discuss turbo issues, here's my experience with the 1.8L:

For my 1.8L 5sp LS Sonic, I tried running three tanks of 91 in a row. I saw no difference in MPG, so I'm running 87 with the 1.8L. No issues.

Note that I live in the northeast (bought the car in Maine, now live in New York), I rarely use AC, not at all like the conditions in the Edmunds article.

But try 2-3 tankfulls of 91 in your Cruze, see what happens!

Don't worry about the 1.8 with what you stick in it for octane. There isn't a turbo or supercharger in there so you don't have to worry about running full synthetics or premium fuel. Cheap gas and synthetic blends will be just fine for the NA engines. It's mostly the Forced induction engines you really have to worry about.

 

[Blue Moon Sonic]

I still submit that running 87 octane gas won't suddenly grenade your engine. Breaking a piston in this engine is nearly impossible under normal conditions. Something went horribly wrong in the engine the OP is referencing, and I suspect that fuel octane wasn't the cause. If 87 is all that is available, I am comfortable putting it in my engine. It is capable of running with that gas and is designed to do so. As the OP points out though, you might find the engine not running at top efficiency.

It's really due to a manufacturing defect in how the pistons were made for the early production engines. The timing retard from the low octane table is what exacerbates the issue with the manufacturing defect, and causes the piston to shatter due to detonation/knock.

 

[6speedti]

It's really due to a manufacturing defect in how the pistons were made for the early production engines. The timing retard from the low octane table is what exacerbates the issue with the manufacturing defect, and causes the piston to shatter due to detonation/knock.

So the early production engines your referring too can you be more specific?
GEN 1 or GEN 2 engines?
Model year?

 

[Blue Moon Sonic]

So the early production engines your referring too can you be more specific?
GEN 1 or GEN 2 engines?
Model year?

Gen 1 LUJ/LUV engines built between 2011 to 2012. I Would love to get me an LE2 to play with, but it may be a while yet before that happens.

The cruzetalk forum covers a lot of these issues and is also good to use as another resource in conjunction with this forum. Basically the same car.

 

[6speedti]

Thank you. I have a 2015. So I guess I'm good.

 

[suitcasejefferson]

Had I had a choice, I would have gotten the 1.8 engine. I have never cared for factory turbocharged or supercharged engines. They are rarely built strong enough for forced induction. I bought my car to keep my disabled sister from being stuck with it. I'm keeping it because I like it, and it gets 45 mpg on the highway. But having to use 91 octane fuel would bring fuel cost up to about the same as my '06 Mercury Grand Marquis, which gets around 30 mpg on the highway. The difference in cost between 87 and 91 is more than 50 cents a gallon. The Sonic is supposed to be an economy car. I agree it might run better with higher octane, but it works fine as a commuter car. The computer should adjust the ignition timing and boost pressure to compensate for low octane fuel. My 1997 H-D Road King does require high octane fuel, but it has no computer, and it is a toy, so I can justify the additional expense. IMO, if you want to spend extra money on a Sonic, spend it on more frequent oil, coolant, and trans fluid changes.

 

[KartRacer]

I believe it is not possible to replicate 2 months use with different fuels. The little 1.4 turbo reacts both good and bad to every little thing, temp, AC, wind, traffic, stop n go etc.
the turbo will however run better with premium but don't count on better fuel economy.
Experience of 2 vehicles and 160000 miles.

 

[Papasonic]

KartRacer brings up factors causing inconsistent economy and performance with the 1.4 that I also have observed. The AC literally knocks the wind right out of the 1.4. Bucking wind, climbing hills, either too hot or cold ambient temperatures also play havoc with fuel usage. Under ideal conditions; little wind, no hills, moderate ambient temperature, I can consistently achieve (on the DIC) the advertised 40mpg on 87 octane. Under conditions in which I mostly encounter; meaning hills, wind, and AC on, it's closer to 35 mpg.

I have tried 91 octane no ethanol for a few tanks, and noticed little variation in fuel usage. I do tend to use higher octane fuel in summer heat using the AC, as it should allow the engine to run with optimum performance. In winter I use 87 octane as I believe it will allow the engine to start better in extreme cold.

 

[zippypcs]

I am now driving an LE2 1.4 and it seems much better with the A/C on and even better in the wind than the Sonic 1.4. I have driven both tuned and untuned. TQ is a bit better on LE2 factory as well.
Fuel eco on both engines running 91 octane at mid 30's most of the time.

 

[Blue Moon Sonic]

Hmm, I wonder how a tuned LE2 stacks against a tuned LUJ/LUV. I really want one of the new gen LE2 car's to play with, but I really despise how the front end on the new sonic's look compared to the first gen. I'd probably end up picking up a cruze wagon instead if I get my hands on one.

 

[zippypcs]

I had a Sonic hatch. And now I have a Cruze Hatch. At first I wasn't really sure I would like the Cruze more, but after driving it for a month I am really happy with it. And yes LE2 has better power out of the gate and with it tuned I think it performs better than my Sonic. Both were Trifecta tunes. And with 20% off currently on '17 Cruze models It was a no brainer and time for something new. Had 2013 LTZ hatch Sonic and bought 2017 Cruze Premier Hatch for 1300 less than I paid for Sonic 5 years ago.

 

[Blue Moon Sonic]

That's a pretty good deal honestly. I've heard the the LE2 with the 6t35 transmission solves a lot of the issues the LUJ/LUV engines with the 6t40 had. I just can't bring myself to trade the sonic after all the common failure areas are bulletproofed minus the water pump. I'm still waiting for the sucker to die on me to make use of the special warranty. Safe to say I'll be keeping this sonic for another 5+ years. Assuming the transmission holds up, which I highly doubt with the way things are looking currently.

 

[carsNskis]

Don't forget, the Cruze is the Opel Astra... lots more parts potential with that platform. OPC Cruze!

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