Premium Gas in a 1.8L Sonic. . . . ?

[JTee2017]

What do you think .... .? Thoughts?

I was just looking through a Holden Barina (same as Sonic as most know) brochure and found an interesting item.

Under the engine listing it shows the standard 1.6L Non Turbo engine and it's specs. It also shows Recommended Petrol . .. . and "Alternative".
It lists ULP (Un-Leaded Petrol) or PULP (Premiun Un-Leaded Petrol) . .. for slightly higher performance.
Australian petrol has a somewhat different octane rating system than here in the U.S. The standard ULP is 91 RON and PULP is 95 RON. Now, this is where octane numbers need to be clarified. European (World) uses RON. . Research Octane Number and the U.S. uses MON or PON. . Motor Octane and Pump Octane Numbers respectively.

I've included a link to how this works out at the end of this post for those interested, but essentially, 91 ULP is 87 U.S. octane and 95 PULP is 91 U.S. octane.
The point is that according to the Holden Barina specs, its standard 1.6L non turbo engine can get "slightly better performance" using a 91 U.S. octane than the regular unleaded 87 U. S octane equivalent.

Included at the end of this post is info on comparing European (World) octane and U.S. octane numbers.

So it makes me wonder if the 1.8L non turbo engine in our U.S. Sonics might also benefit from using 91 octane fuel here? I've started using 89 and the next tank will be 91 or 93 octane in my 2017 Sonic HB with the 1.8L. I have to say, it does seem more responsive using even 89 octane. It seems at least noticeably quicker off the line at stop lights with a healthy press of the pedal to get and hold the engine between shifts at 3,000 to 3,500 RPM. I've found that this RPM range for the 1.8L is a sweet spot and where it comes more alive . . . thinking the variable intake manifold switches over at that point? (I just checked this. . Variable Intake takes over at 4,000 RPM, but peak torque is at and continues about 3,800 RPM.)

Anyway, I just thought that Holden recommends a premium fuel in its 1.6L non turbo engine for "slightly better performance".

Holden Barina (Sonic)
1.6 litre engine. Four cylinders. Double overhead camshafts operate four valves per cylinder.
Aluminium head. Multipoint fuel injection. Variable intake manifold. Adaptive knock control system
Bore x stroke (mm) 79 x 81.5
Capacity (cc) 1598
Compression ratio 1) 9.5
Power (ECE)# 76kW @ 5800rpm
Torque (ECE)# 145Nm @ 3600rpm
Gear ratios Manual Auto
1st 3.54 2.87
2nd 1.95 1.57
3rd 1.28 1.00
4th 0.97 0.70
5th 0.76 –
Final drive ratio 3.94 3.84
Recommended petrol ULP (87 U.S. octane equivalent)
Alternative PULP for slightly higher performance (91 U.S. equivalent)

https://www.carsguide.com.au/holden/barina/price/2017
https://www.etuners.gr/fuel/
https://www.just-auto.com/analysis/analysis-holdens-future-under-gm-and-groupe-psa_id177300.aspx

 

[Smartdave]

For 160k miles I have been putting in the cheapest fuel I can find. I have never used premium fuel.

No issues and I get 35 mpg

2012 1.8


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[JTee2017]

For 160k miles I have been putting in the cheapest fuel I can find. I have never used premium fuel.

No issues and I get 35 mpg

2012 1.8


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That's being Smart. . . . Dave. (see what I did there?)

I was doing it not for better MPG or save any cost on gas, but to see if performance is somewhat better. So far, to me, brisk starts from a dead stop seem improved running even 89 octane. I doubt I will stick with it since Premium now is well of $3/gal. 91 Octanne Premium with no Ethanol is now $3.49/gal here.

Yeah, I though I would just try premium for a couple of tank fulls just to see. I am averaging 31.4 over 2,600 miles of mixed driving. Most of it in town and semi rural and about 35% 65 to 70 MPH. . . and the last tankful running the A/C.

I just thought that the key point is Holden includes the statement that Premium PULP (Premium Un-Leaded Petrol) can be used for "Slightly better Performance".

To me that would imply the ECM can adjust and maybe advance the spark timing or at least not retard it.

 

[Smartdave]

Lol I do...


For me. I bought a cheap car to put cheap gas in. Ha.




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[gnonne]

A long time ago I owed a Dodge Dakota 4 cylinder, 5 speed pickup. No power steering, no AC, no radio, and it was white. I used it to deliver pizzas. One night I was really tired and pushed the wrong button on the gas pump after work. Put in a tank of 93. Truck had well over 100k miles on it and that gas made it run better than new.

More recently, I owed a 460cc Aprilia scooter. That was a nice ride, all metric gauges, etc from Italy. Recommended fuel was premium and that big single-cylinder engine ran a lot quieter on premium. MPG was about the same as 87 (55-65 MPG depending on throttle usage), but much better performance. Tank held about 2.3 gal, if I remember correctly, so maybe $0.75 extra per fill up.

Anything will probably run better on higher octane, but when the computer adjusts for it, your MPG may not change much.

 

[OssiansFolly]

I've been putting mid-grade in since I got the car in February. I've almost exclusively used mid-grade on all my cars. My last 3 cars ran to well over 250,000 miles. Obviously the gas isn't the sole reason for that longevity, but I'm sure it didn't hurt.

 

[Ponchoguy]

For 160k miles I have been putting in the cheapest fuel I can find. I have never used premium fuel.

No issues and I get 35 mpg

2012 1.8


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I put in regular Top Tier gas from a station that is busy, so I know the product is fresh and moves a lot. I've used 87 octane since day 1 in it, no problems.

 

[sarrm]

I've put 91 or higher in my 1.8l auto since I bought it in December 2014. Its a 2012. I only do city driving, small trips mostly with a bit of highway here and there. I'm getting horrible mileage at 11.4L per 100km. It's a pig on gas. So I can say it's not helping but I still put premium in since it helps me sleep better at night lol.

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[Vicarious]

I think it'd be a waste (the efficiency bonus wouldn't outweigh the added gasoline cost). If you were really hellbent on it, you could do a water/meth injection that would achieve similar results for considerably less cost.

 

[Chazzz]

Colder temps and winter blend gasoline means at the very least a several MPG drop in fuel economy along with performance, regardless if it's 87 octane or higher or ethanol free or not. My goal with this car is to find the least expensive fuel possible and any slight gains in gas mileage or performance, that may or may not happen, to me isn’t worth the price premiums of higher octane or ethanol free fuels. Now if I drove a Fiesta ST I would definetly be running premium....

 

[sarrm]

Do you think it would be safe for me to start using 87 after I've used 91 or higher the last 4 years straight? Just scares me

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[Smartdave]

Yes

Put it this way I have 180,000 miles on my car and it has never seen anything except the cheapest gas I can find.

Now the oil changes I do with mobile one synthetic


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[JTee2017]

Lot's of opinion on regular/premium fuel. Not really what this thread is about.

In post #1. . I was just stating why I was trying using at least 91 to 93 octane in the 1.8L because of what I know about how GM ECMs usaully are programmed.
Even on an N/A engine like the 1.8L engine knock can occur fairly often and timing is pulled back. You will never hear knock, and you also not know if the retard in timing is causing less than the best pep out of the engine or not.

By using premium over a period of +4 months over Summer I can say that the 1.8L runs better and has better throttle response on 91 to 93 octane than using 87 octane.
I rarely need to put more than 10 gallons into the gas tank so 20 cents more per gallon is not a big thing. Especially if the engine timing is not being pulled like it apparently does on regular 87 octane. $2 more per fill up is worth a bit better throttle response to me and in my opinion.

One thing people need to know about trying higher octane fuel after running lower octane to see if things improve. . . . is that you will not notice a difference immediately and probably not even on the first fill up with 91 or 93 octane fuel. It takes awhile for the fuel tables in the ECM to adjust to not needing to pull timing and fuel trims. But if all things are good on the engine sometime on the second tank full of premium you will notice a definite improvement in throttle response and somewhat better pick up.

It's just a personal choice and all the other arguments pro or con for using premium are not the point. I am not looking for better MPG, expecting gains in HP or torque. . . just optimum operation that the engine can provide without pulling timing. All it takes is a regular pattern of occasional engine knock that you will not even notice and the ECM will begin to retard timing and store those values in the current calibration table. It "learns" and responds in kind. When going to premium , the ECM also has to "learn" that it no longer needs to use the old timing parameters and can then start to build a new table. That is when you will start to notice smoother running, a little less pressure on the gas pedal and less tendency of the engine to bog down.

The 1.8L has a dual stage intake tune. The change over point from low RPM tune to higher RPM tune starts at about 4,200 RPM, but torque starts to build even at around 3,500 RPM. When premium fuel is used and you keep the engine RPMs in the 3,500 to 4,500 range the engine pulls really well for it's size. Using premium fuel only aids this process that much more based on what I see.

 

[sarrm]

Well I'm gonna keep using premium. Theres a picture that was posted on here(not sure where now) but of an engine using 87 and a engine that used 91 or higher. 87 looked like it had greasy tar lungs while running 91 looked clean. Not sure if it was legit but still makes me feel better putting top tier. I plan on passing the car along to my mother in a year and a half and want to feel like I maintained it. Which I do feel putting in premium will increase the longevity of the car. To each there own.

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[Chazzz]

In order for a gasoline to qualify as a top tier brand it must contain the detergent additives across all octane grades, so you will still get the desired engine cleaning effects regardless if you run 87 89 91 or 93 octane if you use a top tier fuel. To learn more google top tier gasoline, all the top tier brands are also listed. If keeping your engine running cleaner for the long term is your goal then top tier gas should definetly help, but running higher octane fuel than the manufacturer recommends is simply money down the toilet....

 

[JTee2017]

. . . . running higher octane fuel than the manufacturer recommends is simply money down the toilet....

Maybe not. GM Holden has this in the Barina (Aussey Sonic) Owners Manual for the non turbo engine -

" -
Holden Barina (Sonic)

Recommended petrol ULP (87 U.S. octane equivalent)
Alternative PULP for slightly higher performance (91 U.S. equivalent)

 

[r4tb3lly01]

You can lead a horse to water but you can’t make em drink


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[Z71]

I have been using 87 octane in my 2013 Sonic sedan, 5 speed manual since new. I average 36 MPG with A/C on almost all the time (due to humid climate in Florida).

I never tried 93 octane in this car, but if my mileage increased enough to offset the increased fuel cost and performance increased as well, I would definitely use 93 octane. It never hurts to try better octane and see if there are any benefits to gain. You will not hurt the engine by switching back and forth between octanes. The engine is designed to run on 87 octane.

I am pretty sure that acceleration from a standing start and also high speed acceleration would be improved if using 93 octane because the ignition timing could advance more without the engine knock. The engine computer will advance the engine timing the maximum amount and it can advance ignition timing more degrees with higher octane fuel.

 

[JTee2017]

I have been using 87 octane in my 2013 Sonic sedan, 5 speed manual since new. I average 36 MPG with A/C on almost all the time (due to humid climate in Florida).

I never tried 93 octane in this car, but if my mileage increased enough to offset the increased fuel cost and performance increased as well, I would definitely use 93 octane. It never hurts to try better octane and see if there are any benefits to gain. You will not hurt the engine by switching back and forth between octanes. The engine is designed to run on 87 octane.

I am pretty sure that acceleration from a standing start and also high speed acceleration would be improved if using 93 octane because the ignition timing could advance more without the engine knock. The engine computer will advance the engine timing the maximum amount and it can advance ignition timing more degrees with higher octane fuel.

Yes . agree. . see the above earlier posts where I already pointed all that out. in fact, using an OBD II scanner and data logging I could see timing getting pulled when using 87 octane but not on 91 or 93 octane.
Also, the Aussey Barina (Sonic) manual actually states - - -
Recommended petrol ULP (87 U.S. octane equivalent)
Alternative PULP for slightly higher performance (91 U.S. equivalent)

 

[Vicarious]

I have been using 87 octane in my 2013 Sonic sedan, 5 speed manual since new. I average 36 MPG with A/C on almost all the time (due to humid climate in Florida).

I never tried 93 octane in this car, but if my mileage increased enough to offset the increased fuel cost and performance increased as well, I would definitely use 93 octane. It never hurts to try better octane and see if there are any benefits to gain. You will not hurt the engine by switching back and forth between octanes. The engine is designed to run on 87 octane.

I am pretty sure that acceleration from a standing start and also high speed acceleration would be improved if using 93 octane because the ignition timing could advance more without the engine knock. The engine computer will advance the engine timing the maximum amount and it can advance ignition timing more degrees with higher octane fuel.

You're not going to get a large enough mileage difference to offset the cost of it, basically no car does.