[Mad Myche]

I've logged every penny of gas that has gone into my 6, and my regular brands of gas have been Speedway, Shell, Kwik-Trip, and Mobil.


The results show less than a 2% variance in MPG between these brands. Speedway was the overall winner, and is the only one that is not licensed as Top Tier.

 

[jcme0557]

Wait a minute ... the seat of your pants is full of s***!?


Hope you don't have the leather upholstery.

Groan (and eye roll!) :wink2:

 

[TechZeke]

I have a 2018 with the 2.5L Turbo.

After purchase, I used regular 87 for two weeks. I decided to give 93 a try, and haven't gone back. The engine seems to idle and cold start noticeably smoother on premium. Yes, it's not necessarily 'huge', but it was noticeable enough for me to be confident that it wasn't just in my head.

Though, I'd also note that I remember off-the-line performance actually felt slightly better with 87.

Now that I'm on this forum, I might give 87 a try again and report back.

 

[Archerfish]

I have a 2018 with the 2.5L Turbo.

After purchase, I used regular 87 for two weeks. I decided to give 93 a try, and haven't gone back. The engine seems to idle and cold start noticeably smoother on premium. Yes, it's not necessarily 'huge', but it was noticeable enough for me to be confident that it wasn't just in my head.

Though, I'd also note that I remember off-the-line performance actually felt slightly better with 87.

Now that I'm on this forum, I might give 87 a try again and report back.

I've read somewhere here that for you to notice the difference, you'll have to drive and reach the upper RPM range. You can give that a try and see for yourself the change in performance.

 

[TechZeke]

I've read somewhere here that for you to notice the difference, you'll have to drive and reach the upper RPM range. You can give that a try and see for yourself the change in performance.

Half way through my tank of 87.

Yes, in the rpm ranges for daily driving on public roads, you probably aren't going to notice the extra HP from 93. I'll give you that.

I will say that I'll still to my guns on the smoothness of the powertrain. The engine is more grainy, raspy, and feels less refined. Again, it's slight, but definitely noticeable enough, for me.

Being able to fill my tank for $20 is definitely nice though. We'll see when I finish this tank off if I decide to go back or not.

 

[TitaniumVT]

...
Being able to fill my tank for $20 is definitely nice though...

Jeez, where do you live to be able to fill your tank for $20? With a 16.4 gallon tank minus lets say two gallons of reserve on empty, it implies a gas price less than $1.50 per gallon.

 

[TechZeke]

Jeez, where do you live to be able to fill your tank for $20? With a 16.4 gallon tank minus lets say two gallons of reserve on empty, it implies a gas price less than $1.50 per gallon.

Not that cheap, lol. I live in Live Oak, TX, a suburb of San Antonio. I typically don't care too much about price/gallon since the cost of living is so cheap in comparison to my income.(Which is also why using 93 isn't really a big deal) I don't think I've actually looked at the price board of a gas station since I've moved here in late September.

I typically refill at the 1/8 notch, with occasionally going towards E depending on situation. It was like $21.something when I refilled with 87. I typically pay around ~$27 for premium.

When I lived in Southern California, I was paying almost $40 per tank with my(now totaled) Kia Optima.

 

[TNewton]

If you have the turbo motor, you get more power out of premium gas. I think cars run better generally on better fuel--in other words, I can tell the difference.

 

[[email protected]]

I’ve discovered that the question isn’t about the grade of fuel. It’s about who to buy from.

 

[Aurion]

I saw a slight MPG boost in my 2018 GT going to premium. Somewhere around 5-8% but the traffic where I am is stop to 50, stop to 50.

 

[maverick333]

I was going to ask that same question, because I had just bought a 2003 mazda 6, i had put in 89 because it had no gas and i need to get the Car home, and a engine light came on, but the Car drove great. Now I know to use 87, it didnt have a owners manual when i got the car, that is why I sign up here. But, she has 195,000 miles on her, so, do I still use 87 for the higher mileage ?

 

[ben70]

have enough other folks commented in favor of 87 octane yet?

 

[Mad Myche]

All I run is 87

 

[idrive]

I was going to ask that same question, because I had just bought a 2003 mazda 6, i had put in 89 because it had no gas and i need to get the Car home, and a engine light came on, but the Car drove great. Now I know to use 87, it didnt have a owners manual when i got the car, that is why I sign up here. But, she has 195,000 miles on her, so, do I still use 87 for the higher mileage ?

If I read your post correctly, running 89 kicked on the check engine light? Went back to 87 and the light went off?
Switching grades should not/will not do that.

 

[chiefwej]

If your check engine light comes on you need to read the codes, not change fuels. The only way that could happen is if you left the fuel cap loose the first fill up and tightened it on the second.

 

[RHCUDA426]

Any knocking can actually be caused by pinging (resistance to detonation not high enough in the fuel.) But this should only happen in very high temperatures or high altitudes and certainly has nothing to do with transmission smoothness. So if you noobs find your car is pinging (ask us first), you may want to switch to 89 for the summer months.

HELP!!! I HAVE A 03 PROTEGE 5 185,000 AUTOMATIC, DRIVE IT A BIT HARD. IT'S FRIGGEN PINGING, BUT ONLY AFTER IV'E BEEN DRIVING AWHILE. COULD IT BE THE ARCO GAS. KNOCK SENSOR IS GOING TO GET CHANGED, NO SWEAT IT COST ME ZERO. I WORK AT A MAZDA DEALER

 

[TalonTsi90]

HELP!!! I HAVE A 03 PROTEGE 5 185,000 AUTOMATIC, DRIVE IT A BIT HARD. IT'S FRIGGEN PINGING, BUT ONLY AFTER IV'E BEEN DRIVING AWHILE. COULD IT BE THE ARCO GAS. KNOCK SENSOR IS GOING TO GET CHANGED, NO SWEAT IT COST ME ZERO. I WORK AT A MAZDA DEALER

WRONG SITE AND PLEASE TAKE OFF THE CAPS LOCK.

 

[Red2016GT]

87. Only 87. Never 91. Premium is most definently not "always better". You're doing more than just wasting money -- Burning a higher grade fuel than your car is tuned to run actually hurts the engine (actually the exhaust system), decreases your fuel economy, and costs you power.

Where did you come up with this.......
It is simply not true.

The skyactive engine can benefit from 91 vs 87.
Especially in the summer months.

 

[Oppa]

I use JP-8 in my JLTV-RV. It's alright but if you spill it it will stink for hours, though...

 

[Fsouid]

I believe if you use a tune and higher compression cams then yes 91 is a must. Also only a tune will requre you to use 91 but if you use 91 on stock engine its waste but 91 wont hurt the engine. It will just burn normally like 87 but no benefit and it will work like 87 also no difference between the both. No 91 wont hurt ur engine ever sometimes 87 is actually more dirty in some gas stations because its cheap thats why people use 91 just for cleaness and not for compression wise.