91 vs 93 octane and GT-R/Sg trim CX-5

[Unobtanium]

I have noted no difference between the two in acceleration. I filmed 0-80 and 0-60 runs, and then watched/edited videos paying attention to the time. These videos were not shot on the same stretch of road, but in both cases I did my best to make sure the pavement was level more or less, and if I was off a few degrees, well, that's the real world and this is a real-world test. In both cases of 91 and 93 octane use, I found the 0-60 time to be in the very high 6 second range, not accounting for "roll out". Roll out will usually lop off 0.3 seconds or so. Both fuels do 0-80 in almost exactly 11 seconds. Before testing the 93 octane, I ran 2-3 tanks of 93 under varied driving conditions through the vehicle. To the best of my ability, I cannot discern an advantage to running 93 octane over 91 octane.

-I have not tested with 87 octane.
-My 91 octane tests were done on A36 tires, my 93 tests, on LX25 tires. Neither lost traction, nor was there a size or weight difference (published data) favoring the A36, but I am noting 1-2mpg less on road-trips with the LX25's, so they cannot be ignored as a possible issue, but again, this is real-world testing, and if tire brand in non-traction-limited testing matters more than octane rating, then octane rating doesn't matter.

 

[Bosetsu]

I agree with you regarding no difference between 91 and 93 octane. I've also noticed no mpg benefit from running 93 so I've stopped doing whole tanks of it. Costco gas has been good to me so I usually do a mix of 87 and 93 for a good medium of power and mpg though it's probably all in my head

 

[velocityc6]

Not surprised by your results, usually beyond 91 octane will not yield worthwhile results due to factory tuning.

 

[Avoidin Deer]

Not surprised by your results, usually beyond 91 octane will not yield worthwhile results due to factory tuning.

But Mazda's specs cite maximum HP with 93 octane, not 91. One would think that the most beneficial marketing value would be had by citing 91 if benefits really maxed out there.

I see a mileage difference between 87 and 93, but that's not on a dynamometer under controlled conditions. Performance is so subjective I wouldn't even pretend to see a difference.

 

[ZoomZoomForever]

Not surprised at all really.

A tune could possibly yield 20hp with 93 over 91.

 

[velocityc6]

But Mazda's specs cite maximum HP with 93 octane, not 91. One would think that the most beneficial marketing value would be had by citing 91 if benefits really maxed out there.

I see a mileage difference between 87 and 93, but that's not on a dynamometer under controlled conditions. Performance is so subjective I wouldn't even pretend to see a difference.

Interesting, I didnt even realize Mazda stated 93 was needed for max power on the turbo. Here and in other states 91 is already considered "premium".

 

[Avoidin Deer]

Interesting, I didnt even realize Mazda stated 93 was needed for max power on the turbo. Here and in other states 91 is already considered "premium".

Attached is the 2019 CX-5 Features document that shows HP & torque for all the trims.

It has all the specs on each trim. That's how I noticed the transmission gear ratios are different in the turbo models versus the NA models.

I wish I could find the 2020 version of this, since the turbo has that extra 10 ft# of torque and the enhanced balancer(?) in the transmission. I wonder if anything else changed...

 

[Unobtanium]

The 93 octane run was performed after several tanks of 93 octane were used, cycling from less than 25mi on the dash.

The 87 octane run was performed after a mixed tank of 93 and 91 was reduced to 8mi on the dash, and 87 octane was filled in the amount of 10 gallons. The vehicle was then driven 30 miles or so and several key off/engine off cycles were completed, as well as various amounts of throttle input until the run was performed.

This was not the same stretch of road, ambient temp differed, and TSC was not turned off on the 93 octane run (although I noted no issues), and the "HOLD" feature was used on the 87 run but not the 93 run (again, no issues noted).

 

[DwightFrye]

We can't even buy 93 octane here in Commiefornia. If I could, that is all I would run in my CX 5 turbo. So far it has had an exclusive diet of 91 octane. I don't drive that much so the cost of premium fuel doesn't bother me much, and in this over taxed state 91 octane already runs over $4.00/gallon. I have only put a little less than 5000 miles on my car since June and about 2000 of those were running back and forth from my old home to my new one while getting settled in.
I live in the mountains now, no more daily commuting at a crawl on the congested freeways so I want the extra horsepower available with the premium fuel.

 

[Sig cx-5]

...
I live in the mountains now, no more daily commuting at a crawl on the congested freeways so I want the extra horsepower available with the premium fuel.

Do you really spend that much time above 4k RPM? That's where the premium fuel HP and torque advantage starts?

 

[mac.mc78]

Do you really spend that much time above 4k RPM? That's where the premium fuel HP and torque advantage starts?

A lot of people probably don't even realize this.... For most of us, we're sitting down at the 2-3000rpm range for MOST of our commutes/drives, so the advantage of premium fuel is null.

I remember seeing this picture you posted while I was in the purchase-period of my car, and I decided against it too.

 

[yrwei52]

We can't even buy 93 octane here in Commiefornia. If I could, that is all I would run in my CX 5 turbo. So far it has had an exclusive diet of 91 octane. I don't drive that much so the cost of premium fuel doesn't bother me much, and in this over taxed state 91 octane already runs over $4.00/gallon. I have only put a little less than 5000 miles on my car since June and about 2000 of those were running back and forth from my old home to my new one while getting settled in.
I live in the mountains now, no more daily commuting at a crawl on the congested freeways so I want the extra horsepower available with the premium fuel.

Since you mentioned high gas price in “Commiefornia”, that I’d use premium gas there too as the premium strangely costs only 20~30¢ more per gallon than regular gas. At this time with oil price dropping like the rock, the regular gas is still at $3 per gallon even at Costco in California, premium gas is not much more expensive percentage wise. In Texas 93 octane premium gas is always at least 60¢ more than regular gas, which currently is $1.93 at my Shell station. Using premium gas is only 6.6% higher than regular gas in California, but it’s 31% higher in Texas! It’s definitely worth the additional cost on premium in California even if it’s just for better cleaning detergents.

 

[mac.mc78]

Since you mentioned high gas price in “Commiefornia”, that I’d use premium gas there too as the premium strangely costs only 20~30¢ more per gallon than regular gas. At this time with oil price dropping like the rock, the regular gas is still at $3 per gallon even at Costco in California, premium gas is not much more expensive percentage wise. In Texas 93 octane premium gas is always at least 60¢ more than regular gas, which currently is $1.93 at my Shell station. Using premium gas is only 6.6% higher than regular gas in California, but it’s 31% higher in Texas! It’s definitely worth the additional cost on premium in California even if it’s just for better cleaning detergents.

Just used an online converter.. here, try 5.24$ for a gallon (Canadian dollars to boot).

You guys have it really good down there at 3.00$ a gallon. lol

 

[pcardoza]

Just paid $2.43 an hour ago near my office outside of Boston. 93 was listed at $3.01. I'm perfectly happy with performance on 87.

 

[Unobtanium]

You guys are paying over $2 a gallon for 87?. Oof!

 

[Avoidin Deer]

A lot of people probably don't even realize this.... For most of us, we're sitting down at the 2-3000rpm range for MOST of our commutes/drives, so the advantage of premium fuel is null.

I remember seeing this picture you posted while I was in the purchase-period of my car, and I decided against it too.

Except that many of us see an increase in mileage with 93, although it's not enough to completely offset the higher price. And for those times we DO put our foot in it, it's nice to have the extra oomph.

I often mention that a couple of other members put forth the idea that the change in timing caused by premium may reduce the chances of oil dilution...I wish whoever that was might happen upon one of these comments and provide more details. Others disagree that such an effect is likely.

 

[Odrapnew]

The 93 octane run was performed after several tanks of 93 octane were used, cycling from less than 25mi on the dash.

The 87 octane run was performed after a mixed tank of 93 and 91 was reduced to 8mi on the dash, and 87 octane was filled in the amount of 10 gallons. The vehicle was then driven 30 miles or so and several key off/engine off cycles were completed, as well as various amounts of throttle input until the run was performed.

This was not the same stretch of road, ambient temp differed, and TSC was not turned off on the 93 octane run (although I noted no issues), and the "HOLD" feature was used on the 87 run but not the 93 run (again, no issues noted).

Overall, about the same acceleration, 93 looked to be a touch quicker.
One thing I noticed was the 1-2 shift with 87 was slower.
Do you notice that often?
Was it just that run?

Honestly, like others have said, most people rarely see much above 4k rpm and I bet, even at low rpm, they rarely give much more than 1/2 throttle, so higher octane would do nothing for them.

 

[Unobtanium]

I

Overall, about the same acceleration, 93 looked to be a touch quicker.
One thing I noticed was the 1-2 shift with 87 was slower.
Do you notice that often?
Was it just that run?

Honestly, like others have said, most people rarely see much above 4k rpm and I bet, even at low rpm, they rarely give much more than 1/2 throttle, so higher octane would do nothing for them.

Honestly cannot tell which is faster when driving. On the clock, 93 octane seems to have gotten to 80 when 87 was still at 77mph or so. Not really big except yeah, that translates into a 2-3mph trap speed diff.

 

[Apollothedog]

I have been using 93 in my GTR. Its about a $3-4 difference per fill up. Why not get all the performance you can out of the car for a few bucks a week?

 

[Sig cx-5]

I have been using 93 in my GTR. Its about a $3-4 difference per fill up. Why not get all the performance you can out of the car for a few bucks a week?

You don't live in my area. At 70c/gal more, it's not worth it for the few times we get the tach above 4k RPM. Back before the gas crisis of the late 2000's, it was 20c more for 93. I'm not sure what changed.