- Admin
- #21
What a great write-up, thank you so much for the time and effort put into this. I've linked to it on our FB group and I'm about to link to it from our sister site as well.
Premium vs Regular MPG: A 34-Tank Test
- Thread starter cvx5832LC
- Start date
So what’s the verdict? That you can run 87 octane in the LC?
- Moderator
- #23
According to the photo of the filler door, a confirmed yes.
If I understand @cvx5832LC ,he made and added that sticker himself, it isn't actually an official sticker, is that correct?
- Thread starter
- #25
That's my conclusion for now. There is an efficiency loss, but how much of that can be attributed to winter gas? Beyond the scope of my data, unfortunately. The MPG difference is also within 1.7% of each other, and that could also easily be variances in my driving for the season.
Someone pointed out a bigger than $0.38 variance between premium vs regular in their parts. In those cases, the savings are bigger.
- Thread starter
- #26
Welcome to Nuke's humor
- Moderator
- #27
Now I AM confused! However, that does not take much... 
$1.00 per gallon difference for me to fuel with nitro+ which is 93 octane.
Great write-up and research, cvx58LC.
The price difference in the Midwest generally hoovers around $.75 to $.95 per gallon.
I have taken two 400 mile round-trip journeys and have been at 22 mpg both times. Avg speed 70-75mph. A few slow downs for towns.
I truly believe it runs more smoothly on Premium. When I had it delivered new from the dealer, I had it brought in approx 350 miles. I am certain the driver didn't put Premium in it during refuel. It seemed to run a bit ragged until I ran all of that 87 out of it. It is now unbelievably smooth and quick.
The price difference in the Midwest generally hoovers around $.75 to $.95 per gallon.
I have taken two 400 mile round-trip journeys and have been at 22 mpg both times. Avg speed 70-75mph. A few slow downs for towns.
I truly believe it runs more smoothly on Premium. When I had it delivered new from the dealer, I had it brought in approx 350 miles. I am certain the driver didn't put Premium in it during refuel. It seemed to run a bit ragged until I ran all of that 87 out of it. It is now unbelievably smooth and quick.
- Moderator
- #30
Do you use Top-Tier fuel? Doubtful the delivery driver did...
Yes. Always use top fuel.
I asked someone with a 2025 LC and he said the fuel door still says premium only. I’m wondering if what we saw as 87 octane and higher was photo shopped.
- Moderator
- #33
Wondering the same thing...
There is no room for facetiousness on this forum. It is lewd, lascivious, salacious, and outrageous.....
100% you can
This engine has a compression ratio of 11:1 ... it needs higher octane fuel. If you want shorter engine life and subpar performance, use regular.
I will use 91 octane or more ...and I'll sleep well knowing I am doing what's best for longevity and performance.
I agree with the earlier entry that this engine runs smoother and performs as it should with premium. I run non-ethanol 91 octane in my FJ40 and it purrs...
As the old adage goes..."penny wise, pound foolish" ...This is an expensive vehicle...treat it as such and it will treat you well.
Happy New Year!!
I will use 91 octane or more ...and I'll sleep well knowing I am doing what's best for longevity and performance.
I agree with the earlier entry that this engine runs smoother and performs as it should with premium. I run non-ethanol 91 octane in my FJ40 and it purrs...
As the old adage goes..."penny wise, pound foolish" ...This is an expensive vehicle...treat it as such and it will treat you well.
Happy New Year!!
When performance matters vs anything else.
