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

[K-Bob]

In our shop right now is a 1.4t with only 30k miles with a broken piston due to severe detonation (spark knock).

I saw the busted piston and talked to the tech. This is the same GM master tech I go to with my car.
It is very important to use at least 89 octane in these engines. My tech recommends 91 octane and strongly urged me to never ever never put 87 in mine.
These are high temp, high pressure engines, and it is a little odd that they are one of the only turbos that do not spec premium fuel.
I had already made the decision to use 89 octane since my car obviously runs smoother and gets better mpg with it. And after seeing that broken piston I am for sure never using 87 again.
It is well documented that these cars are programmed with a 91 octane curve.
So if you want your engine not to explode, with the added benefit of marginally better performance, run premium (or at the very least 89).

 

[Blue Moon Sonic]

Here is an article from Bad News racing That explains exactly this.

http://store.badnewsracing.net/Which-fuel-should-I-use-in-my-LUVLUJ-Does-it-matter_b_1.html

 

[diazmjd]

Good to know. I've not been religious about 93 like I was in my WRX and GTI. Idiot me for trusting Chevy.

 

[skurtov]

Yeah, no matter what any forced induction car should always be running 93. The cost benefits in terms of MPG's equal out

 

[Blue Moon Sonic]

Yeah, no matter what any forced induction car should always be running 93. The cost benefits in terms of MPG's equal out

Too much of blanket statement with 93 since 93 has 10% ethanol in it, unless your in a state that has 93 no ethanol. The best gas to stick in any forced induction vehicle is 91 no ethanol if available. The reason I state this is because My MK6 Golf R absolutely hates 93 octane with 10% ethanol, but loves 91 with no ethanol and that's just because of how it is tuned from the factory. I've done the comparison, and I've lost 75 miles of range using 93 with 10% ethanol vs 91 without and the car ran 3% leaner with the Ethanol infused gas.

 

[MS93]

I no longer have my Sonic with the 1.8L. I just bought a 2017 Cruze with the 1.4T and although the owners manual does say you only need to use 87 octane, I have heard rumors of the Cruze forum that there was a misprint in the manual and since it is a turbo engine, you have to use at least 89. I've also heard that someones Cruze also needed a new engine after right around 30k miles due to only using 87. :O

 

[Papasonic]

As auto enthusiasts, for which we all are, contributing to this Forum; the topic of which fuel, which oil, and which coolant are all hot button topics.

I agree a turbo, or any forced induction type engine probably will perform to its maximum potential with the best available, highest octane, and if available, no ethanol fuels. But I have to disagree with the statement that no one should ever use less than 89 octane fuel in the 1.4 turbo. This engine was engineered to accept 87 octane fuel, and with sensors to monitor and adjust fuel trim, boost, and timing advance, can operate safely with the recommended fuel. That being said; if the engine (using 87 octane) is operated in a manner such as operating at full throttle in too high a gear (lugging) for excessive periods; I can see where even the engine management systems may not be able to compensate. These engines do not like to see excessive loading, and live longer if allowed to rev freely. I can visualize an operator driving a manual transmission 1.4, in high gear, going 45 mph, throttle to the floor; something has to give!

Personally I vary the fuel octane I use in my 1.4. In winter, cooler weather and normal commuting conditions, I use a top tier 87 octane fuel. In hotter summer conditions and frequently using the AC, or maybe demanding a little more engine performance, I use a top tier 91 octane, no ethanol fuel. I believe this practice is more cost effective, and not detrimental to the engine.

 

[suitcasejefferson]

There is no non ethanol fuel in the states I drive in most, AZ, CA, OR, and WA. While I don't doubt that it is best to use high octane fuel ( I have a truck that was built both for drag racing and street use, and use 100 octane race gas in it, at around $6.50 a gallon. It still has ethanol in it) but with the entire engine management system on the Sonic controlled by a computer, it should be able to handle 87 octane.

One thing I find very frustrating on the Sonic is that it has no gauges. No temp gauge, no oil pressure gauge, and for a turbo, no boost gauge. My 1987 Buick Grand National had all of those. I have no idea how much boost the Sonic turbo makes. But both the ignition timing and the wastegate should be controlled by the computer and the knock sensor. I've never heard any pinging from mine. I did notice that it shifts into top gear at a very low rpm when driving in town, another EPA measure to save gas.

 

[Papasonic]

One thing I find very frustrating on the Sonic is that it has no gauges. No temp gauge, no oil pressure gauge, and for a turbo, no boost gauge.

But it has a fuel gauge!

 

[MaD]

My 14 auto 1.4t likes to up shift fast at low speeds... kinda annoying and lugs the engine... but I just put it manual and keep the RPM's up as needed, as far as the fuel, like suitcasejefferson said about the states all having ethanol... ya it's everywhere [emoji53]

Sent from my SM-G900T using Tapatalk

 

[Blue Moon Sonic]

as far as the fuel, like suitcasejefferson said about the states all having ethanol... ya it's everywhere

Sadly, It is and it's unfortunate for guys who have old, unmolested classics. They can't run ethanol infused gas because it'll eat through the lines and wreck the fuel system. What do they run instead? Run Aviation Fuel? That would certainly get those engines to run like they used to.

One thing I find very frustrating on the Sonic is that it has no gauges. No temp gauge, no oil pressure gauge, and for a turbo, no boost gauge.

What else do you expect from a $14,000 base price econobox. Shame on GM though.

 

[StickyToes]

To find Non-Ethanol gas near you, go to: https://www.pure-gas.org

 

[pljenkins]

Closest real gas is about 300 miles away from me, and I live in oil country, for crissakes...

Anyway, I am HIGHLY suspicious of the OP. Unless you've modified your engine in some way, 87 octane fuel is perfectly acceptable for this engine. For a piston to fail in a stock 1.4 turbo engine there had to be a defect in the casting or some other rare issue.

This car is engineered to use 87 octane and there are tens of thousands of these cars running nothing but 87 octane still running happily in the 6 digit mileage range on the original pistons.

Feel free to run high test fuel in your Sonic. It will happily burn it, but the only reason performance will improve is from the lighter wallet in your pocket not weighing down the car.

 

[DuluthSonic]

I had posted a thread on here a few months ago regarding if it was ok to use 91 non-ethanol fuel in my 2014 1.4 turbo. After having any fears calmed, I can now say that is all I have been using for the last few months. The car runs much better than with the 87 ethanol and the difference is very noticeable. Also, my MPG's have settled in at 36 city & 40 highway. Usually the good stuff runs about .40 cents a gallon more but for the better performance and the extra MPG's I think it is more than worth it. And now after reading this thread, I'm more convinced than ever to keep using it.

 

[JTee2017]

Sadly, It is and it's unfortunate for guys who have old, unmolested classics. They can't run ethanol infused gas because it'll eat through the lines and wreck the fuel system. What do they run instead? Run Aviation Fuel? That would certainly get those engines to run like they used to.

Um. . Well, you need to get out a bit more .. lol.
Check your local Kwiktrip. Many have 91 Octane Ethanol Free gasoline.

Also Cenex stations stock both 89 and 91 ethanol free at many stations. Even our local Exxon now has 91 Octane non ethanol.:banana:

Most motorcycle owners will only run non ethanol.:banana:
And for portable power equipment like chain saws, grass trimmers, lawn mowers, etc. . . non ethanol is best to use. I do.

:banana: -----------------:banana:---------------:banana:

^-----^-----^ Kinda hard on the eyes to read with all the *bananas* going on .. . . ain't it! - opcorn:

 

[Blue Moon Sonic]

Um. . Well, you need to get out a bit more .. lol.
Check your local Kwiktrip. Many have 91 Octane Ethanol Free gasoline.

Also Cenex stations stock both 89 and 91 ethanol free at many stations. Even our local Exxon now has 91 Octane non ethanol.:banana:

Most motorcycle owners will only run non ethanol.:banana:
And for portable power equipment like chain saws, grass trimmers, lawn mowers, etc. . . non ethanol is best to use. I do.

:banana: -----------------:banana:---------------:banana:

^-----^-----^ Kinda hard on the eyes to read with all the *bananas* going on .. . . ain't it! - opcorn:

Until you get into Illinois, then finding non-ethanol gas is a headache. Just one more reason for me to hate going into that state.

I know where a lot of the 91 no ethanol stations are in the cheese lands. There are many by where I go. But, none compare to Kwik trip. Because they actually sell good hot food.

 

[Blue Moon Sonic]

Closest real gas is about 300 miles away from me, and I live in oil country, for crissakes...

Anyway, I am HIGHLY suspicious of the OP. Unless you've modified your engine in some way, 87 octane fuel is perfectly acceptable for this engine. For a piston to fail in a stock 1.4 turbo engine there had to be a defect in the casting or some other rare issue.

This car is engineered to use 87 octane and there are tens of thousands of these cars running nothing but 87 octane still running happily in the 6 digit mileage range on the original pistons.

Feel free to run high test fuel in your Sonic. It will happily burn it, but the only reason performance will improve is from the lighter wallet in your pocket not weighing down the car.

I would go read the link I posted on page one by bad news racing. It even has timing tables for proof to show you why you shouldn't run 87 in a forced induction car. Just because a manufacturer makes a vehicle for the lowest grade gas, does not mean you should always use the cheapest you can get. I go by actual data, not by what the general populace does with their vehicle. That's literally following what the sleazy sales rep told them.

So while the software was engineered to accept a lower octane in case you have no other options, the manufacturer designed the car to run high octane to get the most out of of the vehicle. If one can go from 36mpg hwy on 87 to 44mpg hwy on 91 just by swapping octanes and keeping driving habits the same, then there is obviously something in the software that lets the car run better and more efficiently with the higher octane.

 

[pljenkins]

I would go read the link I posted on page one by bad news racing. It even has timing tables for proof to show you why you shouldn't run 87 in a forced induction car. Just because a manufacturer makes a vehicle for the lowest grade gas, does not mean you should always use the cheapest you can get. I go by actual data, not by what the general populace does with their vehicle. That's literally following what the sleazy sales rep told them.

So while the software was engineered to accept a lower octane in case you have no other options, the manufacturer designed the car to run high octane to get the most out of of the vehicle. If one can go from 36mpg hwy on 87 to 44mpg hwy on 91 just by swapping octanes and keeping driving habits the same, then there is obviously something in the software that lets the car run better and more efficiently with the higher octane.

Okay.. I was ready to level the bulls*$@ cannon at you with well thought out research and statistics.

Then I ran into some real world tests that bear out that indeed the LUV engine is pretty aggressive at dialing back the timing with lower octane gas. No wonder this thing is a pig above 90 degrees!

Though I don't particularly like being smacked down, I will respectfully stay on the mat for the 10 count on this one.

I'll be off now to put some 91 octane in my car.

https://www.edmunds.com/chevrolet/cruze/2011/long-term-road-test/mpg.html

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?

 

[Llia]

Don't care for anything below 91. But 93 isn't always better but it could be the gas station I'm using. I switch between Chevron, Shell, and Valero.

The only time I put 87 was when the fuel ran out and that's all they had. I added two bottles of Gumout Octane booster to be safe.

I have an sick feeling that they still have only 87 in their tanks and I'm paying 93 prices as the car runs really bad when warm. Not at all like it used to.

 

[pljenkins]

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.