87 vers 93 octane fuel

[XtremeRevolution]

Thank you, I will in a moment here. Of course, any single source is not enough. Hence my additional reference to the FTC protecting America's consumers web page.

FWIW, it also states this knocking only ever occurs in a small percentage of cars.

Yes, it does, but the Cruze is not part of that generalization. Again, it has a turbo that creates a high dynamic compression, and under loads and higher temperatures, it benefits from higher octane fuel, running much smoother and achieving better fuel economy.

[bryanakron40]

The single biggest reason this doesn't apply to the Cruze......the FTC article's date is 2003.
They make it so the engine can run on 87 so cheap skates won't whine about having to spend more on gas. It is an economy car after all.

[OnlyTaurus]

All the F*****g tuners logging knock while driving isn't enough? Christ, I am tired of people like you spreading bullshit around the internet. No **** the car is pulling timing when it knocks, that what a knock sensor is there for! Detects knock and then retards timing.

Have you also ever though about how engines work? Do you know why higher octane is needed? Do you understand turbo motors? Do you understand compression? Do you understand anything that isn't in a Youtube video?

Easy Rambo.

Not everyone 'tunes', let alone understand how a vehicle even works. Not saying wayztr doesn't know a thing, but if you going to explain how a sensor or operation works, do so in a polite manner.

Thanks.

[ErikBEggs]

Take a look at 2011 Chevrolet Cruze LTZ: The Ultimate Hot Weather MPG Test - Regular vs. Premium. Edmunds took a 2011 Cruze LTZ and put it to the test using both 87 and 91 octane. What they discoverd was that the car performs enough better on 91 octane that in many cases makes the car actually less expensive to operate on 91 than on 87. Their measurements are pump to pump based, not DIC based. Basically, don't trust just a single source, especially when it comes to how complex systems operate.

I don't like this article at all. It is hardly scientific. Inside Line / Edmunds are not scientific at all with their tests (the same people who can only manage 32 MPG maximum in a Cruze?!?) and have some lead foot journalists. Also keep in mind that this is 100+ degree temps which are conditions 90% of people on here will not encounter every day.

I really think if you aren't tuned you will be fine with 87 Octane. I never had any issue with it and tried 4 tanks regular vs. 4 tanks premium (91) before tuned. There was no noticeable change in fuel economy, but a difference in throttle smoothness when pushed. Pretty much every turbo car on the market now is certified to run on 87 Octane gas and their power ratings on 87 are either listed as just slightly below their premium fuel ratings.

[spacedout]

Looking at the engine specs of the new ford Fusion ecoboost engines they actually list two different horsepower numbers for each engine. One with premium & one without. The 1.6T in the fusion makes 5HP more with premium, the 2.0T makes 9HP more with premium.

Obviously with a turbo to run 87octane the computer has to detune the engine, nice to see some manufactures actually show this on paper.
Ford - Cars, SUVs, Trucks & Crossovers | Ford Vehicles | The Official Site of Ford Vehicles | Ford.com

I'm not saying this is the same case with the cruze, though my well calibrated butt dyno says it is.

[XtremeRevolution]

Looking at the engine specs of the new ford Fusion ecoboost engines they actually list two different horsepower numbers for each engine. One with premium & one without. The 1.6T in the fusion makes 5HP more with premium, the 2.0T makes 9HP more with premium.

Obviously with a turbo to run 87octane the computer has to detune the engine, nice to see some manufactures actually show this on paper.
Ford - Cars, SUVs, Trucks & Crossovers | Ford Vehicles | The Official Site of Ford Vehicles | Ford.com

I'm not saying this is the same case with the cruze, though my well calibrated butt dyno says it is.

I am fairly certain this is the case with the Cruze. I'm sending Tom Read an email asking if the HP numbers are taken using 87 octane or 93 octane.

[XtremeRevolution]

I don't like this article at all. It is hardly scientific. Inside Line / Edmunds are not scientific at all with their tests (the same people who can only manage 32 MPG maximum in a Cruze?!?) and have some lead foot journalists. Also keep in mind that this is 100+ degree temps which are conditions 90% of people on here will not encounter every day.

I really think if you aren't tuned you will be fine with 87 Octane. I never had any issue with it and tried 4 tanks regular vs. 4 tanks premium (91) before tuned. There was no noticeable change in fuel economy, but a difference in throttle smoothness when pushed. Pretty much every turbo car on the market now is certified to run on 87 Octane gas and their power ratings on 87 are either listed as just slightly below their premium fuel ratings.

The conditions don't need to be 100+ degrees. It just so happens that 100+ degree temperatures are on the severe end of what your car will be affected by. I'd wager that anything above 80 degrees F with A/C on will necessitate the use of premium fuel. Those conditions. With the intercooler being sandwiched between the radiator and the A/C condenser, heat soak is pretty much guaranteed. Since turbo efficiency also drops significantly with higher temperatures, it creates more heat to produce the same amount of boost.

Keep in mind that certified power ratings are in ideal conditions. If you live pretty much anywhere in the united states except for right along the coast, you are guaranteed to be outside those ideal conditions 4-6 months out of the year.

[jadedgamerx]

Another person here to verify throttle surging on 87, vs nothing of the sort on Shell 89. We bought the car after temps had already dropped below the need for AC so I haven't felt the need to test anything higher octane wise. Also, when running on 87 octane and surging occurs due to timing retard, it seems to screw up the transmission behavior a bit for me as well. Like the car is confused on what gear to grab or hold onto based on throttle position because the power output the transmission has been programmed to receive for a given RPM is slightly altered maybe? I'm not well versed on transmission tuning but my gut assumption would be that they are tuned based on speed, rpm, grade and throttle position with a predetermined power output for a given throttle position.

[XtremeRevolution]

I did verify from Tom that the horsepower ratings for the Chevy Cruze are taken with 87 octane. This might explain why some people have put down around the same or more than the rated torque on the dyno with their Cruze on 91/93 octane.

Since we know the car does pull timing with 87 octane, we can safely assume that the 1.4L Turbo produces more power than 138hp/148lb-ft on 91/93 octane. I'd put the numbers closer to 142-145hp and 155-160lb-ft on higher octane fuel.

[jadedgamerx]

I did verify from Tom that the horsepower ratings for the Chevy Cruze are taken with 87 octane. This might explain why some people have put down around the same or more than the rated torque on the dyno with their Cruze on 91/93 octane.

Since we know the car does pull timing with 87 octane, we can safely assume that the 1.4L Turbo produces more power than 138hp/148lb-ft on 91/93 octane. I'd put the numbers closer to 142-145hp and 155-160lb-ft on higher octane fuel.

Free Horsepower!