piatikantrop
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And if you tried both, is there a noticeable difference in power/mpg?
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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. 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.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.
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.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'll let you know after 600 miles. I'm currently at 400 and haven't gone WOT yet.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.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.
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.