[DIYguy]

I keep meticulous gas mileage records and drive almost 80 miles round trip to work in my V6/8AT 2017.
Does it run good on regular?
You bet it does. Hooray for the LGX V6...!
Does it run differently on premium?
Yes, slightly. And I mean slightly.

It averages about 2-3% better gas mileage on regular according to my records.
That is hardly surprising given the higher energy content of regular versus premium gasoline (depending upon how it is blended).
But it idles smoother and is noticeably, to me at least, more "peppy" with premium.
How much more?
It is impossible for me to quantify so I won't begin to try.
That said, I can feel a difference in every day driving situations.

However, this is with my car, in our local weather, our horrendous traffic, my usual driving situations, my driving style (moderately aggressive) and with the partially refined, barely flammable horse p**s we have for regular gasoline around here (the last of which probably has the majority to do with any differences, real or perceived).

Worth the added cost?
IMHO yes, and I do typically run premium, but your results are as likely as not to be different depending upon your unique situation.
Only you can decide.

[wintertopdown]

At empty, I filled up 4 gallons of Regular 87 at Exxon. My avg mpg INCREASED from 20 to 25 without changing my driving style! Less pickup and power, maybe. Too soon to tell. I will continue testing 93 vs 87.

I have used 93 since November 2018 over 5000 miles. Avg is 19mpg, mostly highway driving with some city stop and go.

[Need4Camaro]

Originally Posted by DIYguy

I keep meticulous gas mileage records and drive almost 80 miles round trip to work in my V6/8AT 2017.
Does it run good on regular?
You bet it does. Hooray for the LGX V6...!
Does it run differently on premium?
Yes, slightly. And I mean slightly.

It averages about 2-3% better gas mileage on regular according to my records.
That is hardly surprising given the higher energy content of regular versus premium gasoline (depending upon how it is blended).
But it idles smoother and is noticeably, to me at least, more "peppy" with premium.
How much more?
It is impossible for me to quantify so I won't begin to try.
That said, I can feel a difference in every day driving situations.

However, this is with my car, in our local weather, our horrendous traffic, my usual driving situations, my driving style (moderately aggressive) and with the partially refined, barely flammable horse p**s we have for regular gasoline around here (the last of which probably has the majority to do with any differences, real or perceived).

Worth the added cost?
IMHO yes, and I do typically run premium, but your results are as likely as not to be different depending upon your unique situation.
Only you can decide.

This is a much more reasonable answer and explains given your environment and driving style where premium might be of benefit. Also very true about Premium actually decreasing fuel mileage than increasing. People make this big assumption 'higher quality gas = better performance and FUEL MILEAGE' and this is far from true. The only way you will see better fuel mileage is if the car is designed from the ground up as needing 93...and you put 87 in it causing it to ping, knock and detonate...which isnt the case with the V6.

[DIYguy]

Originally Posted by Need4Camaro

People make this big assumption 'higher quality gas = better performance and FUEL MILEAGE' and this is far from true.

Exactly. The things that refiners typically do to increase octane decrease the BTU content of the fuel by volume.
All things being equal, your gas mileage will likely decrease a little with premium.
Still, I am running premium (91 octane in the PRC) in my V6 exclusively now because it idles better and doesn't exhibit a tiny off-idle hesitation that I noticed when running regular.
For me the differences are worth the slight hit in gas mileage, but again your results and preferences are as likely as not to be different from mine.
Whatever works best for you is what you should do.

[Memphis SS]

Originally Posted by DIYguy

Exactly. The things that refiners typically do to increase octane decrease the BTU content of the fuel by volume.
All things being equal, your gas mileage will likely decrease a little with premium.
Still, I am running premium (91 octane in the PRC) in my V6 exclusively now because it idles better and doesn't exhibit a tiny off-idle hesitation that I noticed when running regular.
For me the differences are worth the slight hit in gas mileage, but again your results and preferences are as likely as not to be different from mine.
Whatever works best for you is what you should do.

I agree, if it makes you feel better to run 93 it’s not going to hurt anything.

It really doesn’t do much since the car is tuned for 87. Most studies show a reduction in fuel mileage and no increase in performance when you run higher octane than what the car is tuned for. I think it more of a feeling than a actual result

[Raptor Jesus]

Originally Posted by Memphis SS

It really doesn’t do much since the car is tuned for 87.

It's already been shown a long time ago that the car has a two different timing maps. If it detects knock it will pull timing. On 87 it pulls timing. The car is not "tuned" for 87. It's tuned for a certain timing threshold and on 87 it will almost always pull timing and make a few less horsepower. It is "tuned" to operate on any gas 87-93 just like any other car made today.

[wintertopdown]

after two trips to and from NYC, I conclude that regular gives me higher mpg and a calmer ride. Throttle responce is less jumpy and smoothly accelerates from a stop. With 93 the car can be driven more aggressivly with a need for speed.

To and from NYC is $12 regular at $2.69 a gallon.