Proud owners: do you use regular or premium gas?

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piatikantrop

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And if you tried both, is there a noticeable difference in power/mpg?
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zroger73

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At my last fill-up, 87 was $2.16 and 91 was $2.52. I drive 1,100 miles per month. Based on the first 400 miles in my Si, it looks like I'll be averaging just under 40 MPG on 91.

1,100 miles / 40 MPG = 27.5 gallons

27.5 gallons * $2.52 = $69.30 per month for 91 octane

27.5 gallons * $2.16 = $59.40 per month for 87 octane

In my experience, using 87 in a vehicle designed for 91 results not only in a decrease in maximum output, but also a decrease in fuel economy of about 0.5-1%.

If I used 87 octane and got 38 MPG instead of 40, then I'd be using 29 gallons * 2.16 = $62.64.

The $7 savings per month isn't anywhere near enough to offset the decrease in performance.

The moral of this story is...USE THE FUEL THE VEHICLE WAS DESIGNED TO USE.
 
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zx2down

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At my last fill-up, 87 was $2.16 and 91 was $2.52. I drive 1,100 miles per month. Based on the first 400 miles in my Si, it looks like I'll be averaging just under 40 MPG on 91.

1,100 miles / 40 MPG = 27.5 gallons

27.5 gallons * $2.52 = $69.30 per month for 91 octane

27.5 gallons * $2.16 = $59.40 per month for 87 octane

In my experience, using 87 in a vehicle designed for 91 results not only in a decrease in maximum output, but also a decrease in fuel economy of about 0.5-1%.

If I used 87 octane and got 38 MPG instead of 40, then I'd be using 29 gallons * 2.16 = $62.64.

The $7 savings per month isn't anywhere near enough to justify the decrease in performance.

The moral of this story is...USE THE FUEL THE VEHICLE WAS DESIGNED TO USE.
Wonder if you can split the difference with 89. For my Altima, I see a noticeable MPG increase with 89 over 87. 91 has no further increase. When 89 is more closely priced to 91 it makes it cheaper to run 87, when 89 is closer to 87 in price then it makes it better to run 89. For me, I saw a ~2.5-3MPG gain with 89 over 87. It was the difference between averaging 44MPG on long highway drives and 47MPG and in the city 25.8MPG and 27.7. I also added a cold air intake and found a ~1.5-2MPG increase. vs just .5-1MPG increase with just a K&N filter.

It's nice that when I run 89 I can go from NYC to DC and get 50MPG in a car the size of an Altima now with the A/C on and radio blaring.
 

zroger73

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Wonder if you can split the difference with 89. For my Altima, I see a noticeable MPG increase with 89 over 87. 91 has no further increase. When 89 is more closely priced to 91 it makes it cheaper to run 87, when 89 is closer to 87 in price then it makes it better to run 89. For me, I saw a ~2.5-3MPG gain with 89 over 87.
I observed this same thing with my 2014 Ridgeline over a 4-year period. 87 was the recommended fuel except when towing (which I never did). 91 was recommended when towing over 3,500 lbs. at high altitudes, high temperatures, or when climbing steep grades. Even though the vehicle was designed for 87, 89 yielded a significant improvement in fuel economy and a small improvement in performance.

My 2017 Ridgeline, on the other hand, seems to run the same with 87, 89, or 91, so I just run 87 since that's the recommended fuel and I exceed the EPA estimates.

I plan to run only 91 octane in the Civic since single-digit fuel savings are of no significance to me.
 


CVCCR

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91 for less detonation on track:D
 

Milo & Miles

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I use 91 as thats the recommended octane for Sport hatch. Never used a lower grade even though I heard that its permissible, just not recommended.

I have tried 94 octane once but noticed no performance or fuel economy difference at all.
 

SecretAgentDannyBeans

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Dealer put in reg, forgot to request premium before I got there. I'll be switching to 91 going forward.
 

kritz

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Are you guys getting the claimed 20.3 pounds of boost? The dealer put regular in mine too and boost was capped at 15 pounds. It's now showing 18 with premium but not 20.
 


zroger73

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Are you guys getting the claimed 20.3 pounds of boost? The dealer put regular in mine too and boost was capped at 15 pounds. It's now showing 18 with premium but not 20.
I'll let you know after 600 miles. I'm currently at 400 and haven't gone WOT yet. :)

Some of the press drive videos pointed out that boost never reached 20.3 PSI. Air is less dense at higher temperatures and higher altitudes. If the 20.3 PSI rating is based on 32°F and sea level and the turbocharger is near its limit, that might explain why we're not seeing full boost. Or, maybe the ECU is "forcing" a break-in period by limiting boost then increasing it over time. Hmmm, now there's a conspiracy theory to chew on! Discuss...
 
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zx2down

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Are you guys getting the claimed 20.3 pounds of boost? The dealer put regular in mine too and boost was capped at 15 pounds. It's now showing 18 with premium but not 20.
I think a few may be doing this to the reviewers. I saw a couple people mention they never saw boost over 15-16PSI but assumed it was due to being a hot day.
 

KeNzOo

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At my last fill-up, 87 was $2.16 and 91 was $2.52. I drive 1,100 miles per month. Based on the first 400 miles in my Si, it looks like I'll be averaging just under 40 MPG on 91.

1,100 miles / 40 MPG = 27.5 gallons

27.5 gallons * $2.52 = $69.30 per month for 91 octane

27.5 gallons * $2.16 = $59.40 per month for 87 octane

In my experience, using 87 in a vehicle designed for 91 results not only in a decrease in maximum output, but also a decrease in fuel economy of about 0.5-1%.

If I used 87 octane and got 38 MPG instead of 40, then I'd be using 29 gallons * 2.16 = $62.64.

The $7 savings per month isn't anywhere near enough to justify the decrease in performance.

The moral of this story is...USE THE FUEL THE VEHICLE WAS DESIGNED TO USE.

Man, i miss those days when prizes of gasoline here in NorCal is below $2 :envy:
 

jpuhl777

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Always 91 for me (longevity and reliability) - its not that much more costly so might as well. There is no higher octane in my areas than 91 else I would be tempted to see the difference between 91 and 93 for myself.
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