This summer I got a new car, a 2016 Mazda3, stickshift, 2.0L. In the US the owner's manual recommends 87 octane and the engine has a 13:1 compression ratio, but in other countries it recommends higher octane and has a 14:1 compression ratio. I was interested in whether higher octane would have any benefit in the US version of the engine.
I didn't do a super scientific test, just did 2 fillups of 87 octane followed by 2 of 93, then 2 more of 87 and 2 more of 93.
Here's the raw data:
Code:
fuelup_date model miles gallons mpg octane
10/17/2016 Mazda 3 309.9 8.295 37.36 93
10/11/2016 Mazda 3 306.6 7.672 39.96 93
9/22/2016 Mazda 3 344.1 7.846 43.86 87
9/9/2016 Mazda 3 334.6 9.286 36.03 87
8/29/2016 Mazda 3 362.1 7.806 46.39 93
8/23/2016 Mazda 3 362.7 9.105 39.84 93
7/28/2016 Mazda 3 331.4 9.206 36 87
7/17/2016 Mazda 3 302.7 8.315 36.4 87
And here are the statistics. I tried to do a box-and-whisker plot, but I can't spare the time to figure out how to make Excel give me what I want!
Code:
87 octane mpg 93 octane mpg
median 36.215 39.9
q1 36.0225 39.22
min 36 37.36
max 43.86 46.39
q3 38.265 41.5675
So it seems I get a little better mpg statistically with 93 octane, but it's certainly not worth the extra cost!
I didn't do a super scientific test, just did 2 fillups of 87 octane followed by 2 of 93, then 2 more of 87 and 2 more of 93.
Here's the raw data:
Code:
fuelup_date model miles gallons mpg octane
10/17/2016 Mazda 3 309.9 8.295 37.36 93
10/11/2016 Mazda 3 306.6 7.672 39.96 93
9/22/2016 Mazda 3 344.1 7.846 43.86 87
9/9/2016 Mazda 3 334.6 9.286 36.03 87
8/29/2016 Mazda 3 362.1 7.806 46.39 93
8/23/2016 Mazda 3 362.7 9.105 39.84 93
7/28/2016 Mazda 3 331.4 9.206 36 87
7/17/2016 Mazda 3 302.7 8.315 36.4 87
And here are the statistics. I tried to do a box-and-whisker plot, but I can't spare the time to figure out how to make Excel give me what I want!
Code:
87 octane mpg 93 octane mpg
median 36.215 39.9
q1 36.0225 39.22
min 36 37.36
max 43.86 46.39
q3 38.265 41.5675
So it seems I get a little better mpg statistically with 93 octane, but it's certainly not worth the extra cost!