Chevy 1.4L Turbo and Octane

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My girlfriend has a Chevy Trax and it's a decent little car, but a little bit underpowered. It's also heavy so the mpg suffers a little bit because of the engine struggling to pull it along.

So, that's why I ask if this little turbo will see any benefit from a higher octane fuel? We plan to run a couple tanks of 89 just to see if there is any noticeable difference and if it makes any more power.

I know in vehicles like my Ridgeline, the V6 will indeed change it's fuel mapping to take advantage of higher octane and even change shift points, as was confirmed by various people/engineers on Ridgeline forums. That manual also states this, albeit with a little less detail.

So, if anyone is familiar with this engine or has credible links to show that higher octane benefits the 1.4l I'd definitely like to read/hear about it.

To be clear, I'm not starting an octane argument, I know that 87 octane technically has more energy and that it's not of lesser quality. I simply am curious whether this ECU and engine can take advantage of a higher octane.
 
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With modern knock control systems, it's likely that most engines can benefit at least a little from higher octane and it might even be more likely for a turbo. I worked on the electronics for a closed-loop knock system to be used by one of the US Big 3 over 20 years ago and the intent was to keep the engine on the very edge of knocking, sometimes knocking so lightly that the driver could not even sense it.
I would guess that the systems used today are even better than the one I worked on, and I got to see it run in a car on a dyno and was amazed by how well it worked. The gain might be so tiny that you won't even notice it, but why not give it a try just to see what happens? I would recommend trying 91 or 93 first to see if you can feel a difference. 93 is recommended for my car and that is usually 50-60 cents per gallon more than regular where I live...my wife is a penny pincher and always has to comment on the cost delta whenever I fill up with her in the car.
 
Try 91 or 93 octane if your area has it. 89 is not a big enough step up to test for any benefits. Higher octane is your friend with higher compression / supercharged engines.
 
Just starting using some 89 and 93 Shell in the Matrix and what a difference. Runs much better. Read the owner's manual that states to use 87 or higher. In parentheses it says research 96 octane. So not a requirement but at it's age I think it helps. Esp for short trips where the extra detergents can sit on the parts. For long trips I'll fill up with 87. But for around town 87 or 93 now. The Camy will get the same higher octane. Every week put in $10 worth of high octane. Since it doesn't see a lot of miles each week. Sure beats filling it up completely with 93 octane. Kind of budgeting thing with the high octane and makes the added cost much more palatable.
 
I have a Cruze with the 1.4T. Super unleaded(91-93 octane) will give you 10-14 more HP per GM engineers. My experience is noticeably more power and better throttle response.
 
I have a 2014 Cruze with the same 1.4T motor. Below freezing, it makes little difference. Once you get up in the 30's, it definitely runs better on 89 octane. By late spring I run 93 octane. Honestly, I don't know how they can even say it runs properly on 87 octane, it doesn't in warmer weather. If it is in the 80's or 90's it will actually retard the timing and bypass the turbo as you accelerate leaving you with little power. It starts out fine pulling into traffic then when I hit about 2000 rpm it feels like it is dying. 93 octane cures all of this.

As for fuel economy, I have found that if you just look at the computer in the car, you'll never see much of a difference. If you actually track gallons purchased per actual miles per tank and calculate it yourself, you will see a difference. The computer is reasonably accurate with 93 octane. If the weather is hot, my computer can say 42 mpg for the tank and I might only get 37 mpg by my calculations if I'm running 87 octane. With 93 octane in that scenario I would get at least 41 mpg calculated if the computer said 42.

In Michigan I run 87 Octane if below freezing constantly.
I run 89 Octane up to about 60 - 70 degrees and 93 octane above that.

You can get away with 89 all summer long, but it feels a little smoother with 93 octane.
 
Originally Posted By: Snagglefoot
Just out of curiosity. Can that motor accept E-85?


The manual for her car (2017 Trax) states "Do not use any fuel labeled E85 or FlexFuel. Do not use gasoline with ethanol levels greater than 15% by volume."

And thanks for the responses guys. Looks like we will be giving 91+ a try for a few tanks to see if we get any noticeable difference in power/mpg.
 
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That's the same engine as my Cruze has. Many owners claim premium is the only way to go - I've tried all grades: it runs noticeably worse on regular, but I've never been able to detect the difference between plus and premium.

Change the (synthetic) oil frequently, observe the other maint. points (plugs @ 60K, air filter @ 40K, etc.) and learn about the common failures of the engine (PCV, water pump, water outlet, etc.) and it should be good to you.
 
my 9:1 comp Nissan with PI needs a little 93 mixed in to make power and low end.

Never drove anything in the past decade that didn't benefit from a little mix in.

These engine are very high output/L Jeepers, My Rouge make same HP as my 4bbl 5.0 Mustang. If it was a 5 litre it would make 350 HP - so Yes IT NEEDs SOME HELP with better fuel.
Good luck finding Premium that isn't STALE though.
 
Originally Posted By: beastykato
Originally Posted By: Snagglefoot
Just out of curiosity. Can that motor accept E-85?


The manual for her car (2017 Trax) states "Do not use any fuel labeled E85 or FlexFuel. Do not use gasoline with ethanol levels greater than 15% by volume."

And thanks for the responses guys. Looks like we will be giving 91+ a try for a few tanks to see if we get any noticeable difference in power/mpg.


That's a shame, since my car's setup (also DI turbo, relatively high CR @ 10:1) has been proven to give a little more power even on the factory tune with some E85 (up to a 20% TOTAL content) mixed in with the 93 E10 (THANK YOU Ford O.A.R. system!!
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).

Sadly for me, the last E85 station within 50 miles one way from me closed down last summer.
frown.gif
 
Originally Posted By: Bjornviken
Use Shell 98 v-power


It's only 93 max here (by OUR octane ratings system), and usually has up to 10% ethanol content in most areas.

But it IS what I use, exclusively in this car.
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Originally Posted By: dailydriver

That's a shame, since my car's setup (also DI turbo, relatively high CR @ 10:1) has been proven to give a little more power even on the factory tune with some E85 (up to a 20% TOTAL content) mixed in with the 93 E10 (THANK YOU Ford O.A.R. system!!
19.gif
).

Sadly for me, the last E85 station within 50 miles one way from me closed down last summer.
frown.gif



I would try running a mixed tank of 93/E85 if the latter was available anywhere around me...I did find something on the web a while ago about it being available at some portside facility in Charlestown MA, but I doubt that was retail.
I did try running about 1/3 of a tank of 100 octane racing gas (unleaded) with the rest 93 and the butt dyno reported no change...same thing with 94 octane in Canada (car actually ran somewhat poorly for that tank).

BTW, FWIW, I read somewhere that the 3.5l V6 in the mid-2000s Lexus RX350 was advertised as 270HP while nearly the same engine in the RAV4 was advertised as 268HP because premium was recommended for the former and regular gas for the latter. A real difference for that engine (2GR-FE, PFI then but I think updated to DI and about 300HP now), but a quite small one.
 
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My 2.0 Edge Ecoboost definitely benefits from 93 octane especially in hot weather. If I fill it with 93 and put the shifter in S the car really comes alive.
 
I haven't done any dyno tests, but my SOTP meter says 93 in my Ford Escape 2.0 Ecoboost runs quicker than 87.
 
Just replying back to give a little update. We have ran one tank of gas thru the car now with 93 in it. It had a 1/4 tank or so of 87 octane in it when we filled it up so the 93 octane we put in was somewhat diluted.

Anyway, I didn't even tell the g/f what I put in the car and she came back home and said the car "seems to be shifting smoother or something". I drove it and did notice that off the line the acceleration was definitely smoother like a dead spot or lag was gone or at least less evident.

Gas mileage has increased about 3mpg. The g/f could not get above 27-28mpg and I had to baby it to get to 30mpg average. She has driven the car and it's still showing an average of over 30mpg. The routes and weather have been the same as always. I'll have to run a few more tanks through it and see if it's just luck or actually helping.

Considering when she drove it she could NEVER get over 30mpg though I'm definitely happy with the results.
 
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