1.5T Regular v. Midgrade v. Premium Gas Performance

echoparkpanda

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So the 1.5T manual recommends regular unleaded as its default source but have seen posts that boast a boost in performance when using premium.

From my experience, using premium boosts the engine response of higher rpm driving even with a resonator delete.

Has anyone experimented with using Midgrade gasoline in their Civics?
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dc2turbo

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is this on a stock ecu with no reflash? probably wont see a difference then.
 

gtman

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I use mid grade 89 octane and it feels a little smoother overall than 87. I'm going to stick with it because I see a small bump in MPG as well.
 

Mikeybc

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Not sure if it's just coincidence but I've usually been averaging about 5.1 l/100km over the course of 800 km on 91 premium with several tanks. One day the attendant put 87 in the tank and I was at 5.3 l/100 km average at around the 800 km mark. I ran that tank almost dry and refilled with shell 91 and got a 5.0 l/100 km average at over 800 km. I might fill with 87 again and see if it goes back up.
 


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echoparkpanda

echoparkpanda

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I use mid grade 89 octane and it feels a little smoother overall than 87. I'm going to stick with it because I see a small bump in MPG as well.
Do you know approx. what MPG you were averaging using regular unleaded vs mid grade?
 

bembol

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Placebo effect?

Three out of five including both my current daily drivers recommend Premium but my first two was regular and I did use a higher grade.

I don't know like posted you'll see the return in increased mileage.
 
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echoparkpanda

echoparkpanda

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Not sure if it's just coincidence but I've usually been averaging about 5.1 l/100km over the course of 800 km on 91 premium with several tanks. One day the attendant put 87 in the tank and I was at 5.3 l/100 km average at around the 800 km mark. I ran that tank almost dry and refilled with shell 91 and got a 5.0 l/100 km average at over 800 km. I might fill with 87 again and see if it goes back up.
That's definitely interesting. From my experience, I had lower MPGs from 87 gas and gained MPGs using 91 octane but this was all during recent summer weather which is something I read awhile back that hotter weather means the intake gets hotter and the lower octane fuel burns quicker than usual. Not 100% confirmed though.
 

gtman

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Do you know approx. what MPG you were averaging using regular unleaded vs mid grade?
Probably just 2 MPG or so. Not huge but the drive just feels smoother at all RPM's with the 89. Around my way, mid-grade is only 20 cents more than 87 so it seems like a good deal. 91 just seems like overkill unless you're tuned.
 


marauderguy

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Not sure if it's just coincidence but I've usually been averaging about 5.1 l/100km over the course of 800 km on 91 premium with several tanks. One day the attendant put 87 in the tank and I was at 5.3 l/100 km average at around the 800 km mark. I ran that tank almost dry and refilled with shell 91 and got a 5.0 l/100 km average at over 800 km. I might fill with 87 again and see if it goes back up.
91 octane in Canada does give slightly better mileage than 87 due to the ethanol content. Virtually all Canadian 91 is ethanol free and 87 contains up to 10 % ethanol. This gives you an approx 2- 3 % increase in mileage.
 

ryanfk7

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Youā€™ll hear from the manufacturer that the 87 octane is fine to use, but to get manufacturers reported numbers (Hp & torque) to use premium, usually 91. If youā€™re on a stock ecu no tune or aftermarket parts, 87 is fine. If you start tuning and adding parts, Iā€™d go 91. Iā€™ve been data logging with KTuner for about a month now and have done testing with 87, 89, and 91 from a station known for quality and consistency. Knocks have been occurring on 87 but nothing to be too concerned about. will add more when I do more testing :thumbsup:
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