Class of 2016-Up: Who uses regular and premium gas and do you notice a difference?

Update: I ran 2 tanks of 91 and one tank of 93, doing some towing on the 2nd tank of 91.

I didn't notice any real-world difference in performance.
The 91 did give me piece of mind in regards to knock/ping protection while towing about 1800lbs and another 300lbs in the cargo area.

I didn't notice a difference in fuel economy, as I was mainly concerned about power.
Also towing and some more-spirited-than-usual driving to see if I could notice any performance difference would have made mileage increases difficult to measure.

I will fill up with some premium and see if I notice a mileage increase.
In my area though the difference between regular and premium is about $0.50 a gallon, running about $2.27 and $2.77 respectively at the moment.
Regular and midgrade go about $2.27 and $2.57 respectively.
So on an 18 gallon fill-up that is $5.40 to upgrade to mid-grade and $9.00 for premium.
So SDL, please let us know where you get such cheap premium gas!

SDL said:

I only put premium on mine. I noticed the slight performance increase, plus I get more mileage per tank. The difference I calculated to be maybe a $1.50 per tank. Worth it.

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snapbox said:

CAREFUL

I have a '16. Over the past few months, I've been moving to 91 and then 93. I'm on my 3rd or 4th tank of 93 - on Monday I experienced a pretty massive computer failure. The car went into limp mode, and I was able to make it home going 15mph. I had it towed yesterday to the dealer, and they're doing a fairly significant investigation into why it happened. They believe it's fuel related, but it's not "bad fuel" - it's something else. While Mazda corporate is trying to figure it out, the local tech said there's no reason to put 93 in the car - anything above 91 is "too rich" and a "waste". He does suggest 91 over 87, though.

I'm currently in a loaner. I'll let you all know what they come back with.

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Update:
Mazda corporate AND regional are now involved. My 16' CX-9 has been at the dealer since Tuesday, and they still don't know what the cause is. Regional has ordered a knock sensor installed to track down the problem, and they do not believe it's bad gas related. Probably a coincidence that it happened on 93 octane, but I'm still told 93 is a total waste and 91 is about the best for our engine.

I'm concerned that I may have a lemon on my hands - I don't want the car back unless they can figure it out.... more to come.

Hope it turns out well Snapbox, and thanks for sharing.

snapbox said:

Update:
Mazda corporate AND regional are now involved. My 16' CX-9 has been at the dealer since Tuesday, and they still don't know what the cause is. Regional has ordered a knock sensor installed to track down the problem, and they do not believe it's bad gas related. Probably a coincidence that it happened on 93 octane, but I'm still told 93 is a total waste and 91 is about the best for our engine.

I'm concerned that I may have a lemon on my hands - I don't want the car back unless they can figure it out.... more to come.

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Id like to be kept in the loop as well... Mine has been making a pinging noise with 91 and worse with 87..... Dealer keeps saying its the variable valve flap in the exhaust manifold.
https://www.mazdas247.com/forum/sho...-try-to-hear-your-engine-if-you-have-the-same

JPL said:

Most people probably aren't going to be accelerating hard from already illegal speeds.

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But some of us will be...(rockon)

dulanypeters said:

But some of us will be...(rockon)

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+1

So I've run a few more tankfuls of premium gas through my CX-9 and I'm getting NO difference between regular at 87 and premium at 91 octane.
I'm averaging 20.6 to 21.5, regardless of gas.
The variation at the moment depends more on weather and when i leave for work.
If I leave for work or leave work early on a cool day, I find i drive less aggressive because traffic is lighter and I'm not running AC.
If I leave late and traffic is heavier and/or I'm running AC, I'm burning more gas.

And I've not felt any improvement in acceleration time.
I HAVE seen an improvement in smoothness of engine operation.
I think that might be due to using Top Tier gasoline.
My local cheapest-gas-around Wawa is inconvenient to my commute.
And since I've been trying the better grades of gas, the price difference for name brand Top Tier gas is more negligible, so I stop wherever I can get Top Tier in 91 or 93.

I have a cx9 and I live in peru where gas is not as good as in the states. Usually higher octane gas is better filtered so we always try to use the premium , also the octane meassurements are different, here our lowest degree is 90 ( its the same as the 87 in the states or a bit lower) and goes all the way to 98 ( 93 in the states ) said this, I have been running the cx9 with 98 octanes and I have noticed a significant difference in the rpm upper range, seems you get much more grunt from 5000 till 5800, before that , between 1000 and 4500 rpms there is no significant difference.

Why Putting Regular Gas Into A Car That Needs Premium Won't Save You Any Money

http://jalopnik.com/why-putting-regular-gas-into-a-car-that-needs-premium-w-1796463139

Soooo...???

bdisco said:

Why Putting Regular Gas Into A Car That Needs Premium Won't Save You Any Money

http://jalopnik.com/why-putting-regular-gas-into-a-car-that-needs-premium-w-1796463139

Soooo...???

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Soooo...our owner's manual, page 3-28, sez "use 87 AKI or above." Our cars don't need premium gasoline. The engine is made to run fine on 87. Up to 91 will give more top end power. The choice is yours.