[cariboocreek]

Originally Posted by xqwisit23

Been 8 yrs since I moved to Canada from the US and the gas ratings up here are different than down south:
87 - Regular
89 - Mid Grade
91 - Premium
94 - Super Premium (only avail at Chevron)

Yes. Even the Canadian version of the Owners Manual indicates 91 octane as the recommended. Only the big cities may have a Chevron station with 94. I have ran Canadian 91 in my Camaros, Vettes, and Mopars for years. Never an issue.

[keep_hope_alive]

This is a useful thread. It is hard to avoid ethanol near me (Iowa) and many stations do not clearly identify if ethanol is present or not. I've been using Lucas fuel conditioner for my Honda and Toyota for the past year and it's greatly improved fuel economy of lower octane fuels. I can find some BP and Shell stations with 93, but some have ethanol.

I'm also careful to avoid older gas stations at lower elevations or areas with high water tables (when I know), but when travelling I just try to find the newest stations.

[James6speed]

89 Shell for 10k miles. No issues as a daily.

[CalgaryZL1]

Originally Posted by James6speed

89 Shell for 10k miles. No issues as a daily.

91 minimum in my car for fear of it sounding like a woodpecker.

[WhiteMale]

I never use less than 93 in my LT4. Carry two can's of boost in the trunk incase I have to grab 91. I wish I had more 93 stations, there's only two in my direct vicinity.

[ctrlz]

Originally Posted by fastliferider

Does anyone other than me run only 93 octane?

I run only 93, which is recommended octane for the SS.
Recommended octane is mainly based on engine geometry (i.e. compression ratio) and then type of aspiration. Supercharging usually mandates the highest octane.
Contrary to intuition, higher octane fuels are less volatile than lower octane, but that also makes them more compressible.
Run higher octane than required and you get excess unburned hydrocarbons.
Run lower octane and you risk uneven burning of the compressed mixture, which is called detonation, and can cause damage. Modern engines use knock sensors to retard spark timing when they sense detonation.

A good phrase to remember is "power-robbing premium," which summarizes the fact that using higher octane than specified will actually reduce power. Fuel companies promote the premium which is higher profit. last time I looked this up the estimate (in the U.S. alone) was something like $20 billion annually wasted on pemium fuels.

[PostalLDMC]

Originally Posted by Gen6cyl

If you can get 93 use it. I use 93 in my v6. If you want to save money use 5w-30 synthetic motor oil.

Why run 93 in a V-6 when it's the 1 engine that can run on regular gas. The higher the number the slower it burns, which is only more carbon build up. That's why some many run E-85. I may be wrong but from other guys that race.
It only makes cents.

[CalgaryZL1]

Originally Posted by WhiteMale

I never use less than 93 in my LT4. Carry two can's of boost in the trunk incase I have to grab 91. I wish I had more 93 stations, there's only two in my direct vicinity.

I also carry octane boost, I’m lucky I have a 94 station close to home

[Ventmaster]

My car has been running on 91 octane since day one (without adverse effect, best I can tell). I would gladly run 93, but I can't find 93 basically west of the Rocky Mountains. They don't even have it in Vegas, even though that's not a practical alternative for me (120 miles away-LOL). I do make sure it's a Top Tier station, but here in S. Utah (elevation about 2,500 feet above sea level) they sell 85 octane as their cheapest gas and a great deal of people use it as their regular!

[CalgaryZL1]

Originally Posted by Ventmaster

My car has been running on 91 octane since day one (without adverse effect, best I can tell). I would gladly run 93, but I can't find 93 basically west of the Rocky Mountains. They don't even have it in Vegas, even though that's not a practical alternative for me (120 miles away-LOL). I do make sure it's a Top Tier station, but here in S. Utah (elevation about 2,500 feet above sea level) they sell 85 octane as their cheapest gas and a great deal of people use it as their regular!

The LT4 recommends 91 minimum but being at 3500 feet elevation and not a daily driver I am lucky that 93 to 94 is more common in my area for me to choose

[JT6Speed]

In a regular SS I don't see an issue with 91, that's still considered premium. Here we get 93 which is nice, usually I run V-Power.

[Rock-It Man]

Originally Posted by LeonardS

There are no stations in North Dakota that sell 93, so 91 is the best I can get. I’m going to buy 55 gallon drums of unleaded 100+ octane and mix it.

But what is your altitude? 91 octane is more or less equivalent to 93 octane if you are always significantly above sea level and achieving a lower compression ratio.

Which may be why there's no 93 octane where you live.

[Gen6cyl]

Originally Posted by PostalLDMC

Why run 93 in a V-6 when it's the 1 engine that can run on regular gas. The higher the number the slower it burns, which is only more carbon build up. That's why some many run E-85. I may be wrong but from other guys that race.
It only makes cents.

Runs better, tuners say so . Let's ecu advance timing. Same compression ratio as 6.2 lt1.I used 87 octane for the first 18 k miles, since then have been using 93 octane.

[LeonardS]

Originally Posted by Rock-It Man

But what is your altitude? 91 octane is more or less equivalent to 93 octane if you are always significantly above sea level and achieving a lower compression ratio.

Which may be why there's no 93 octane where you live.

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