[Rekkless]

Hi all, just this past weekend I picked up a 2018 2SS 1LE and drove it 7 hours back home to Montreal, Canada.

I'm super excited it is hands down the best sports car I've ever owned. My first V8 too, although I've come from a decent line of high performance Japanese vehicles.

My question is in regards to fuel, gas, petrol. I was reading the performance user manual last night (I think it is the one that comes with the 1LE) and in the manual it states that 93 octane or better should be used, 91 octane is OK but will reduce engine horse power and fuel economy.

Problem is in Montreal and Quebec in General, anything better than 91 is pretty hard and expensive to find.

Here in Quebec only Petro-Canada sells 94 Octane fuel BUT they use up to 10% Ethanol to boost the Octane to get to 94.

So I'd like to know are these engines OK with up to 10% ethanol or should I avoid them at all costs?

How is driving a SS with using only 91? Do you find you're down on power?

Basically the 3 options I have locally that I'm considering regularly using are the following:

Petro-Canada = 94 Octane with up to 10% ethanol, also most expensive option.

Shell V-Power = 91 Octane with guaranteed 0% ethanol, mid price Option.

Costco 91 Premium = 91 Octane contains up to 10% ethanol, cheapest option.

I like the Costco option not just because it is the cheapest, (upwards of 30 cents per liter or $1CAD per gallon cheaper than the 94 octane option) and because Costco has an extremely high volume and turn over of gas, meaning it's highly unlikely I'll get old stale gas. They also claim their gas meets all manufacturers requirements and is Top Tier Certified.

https://www.costco.ca/gasoline-q-and-a.html



So what is everyone's opinion? Since it is impossible to get 93 Octane or better fuel with no Ethanol should I stick with V-Power from Shell? Or is 10% and 91 octane fine and should I save money by using Costco 91?
Or do these cars really respond to 93+ Octane regardless of Ethanol content?

Obviously there are other options like ESSO and Canadian Tire which their 91 has no ethanol. But only Petro Canada offers 94.

[Devius83]

I use Chevron 94 octane no ethanol
Not sure if you can find chevron but in bc its the only option i have

[LT4Greg]

I would use Shell V-Power! My ZL1 runs real good on it but it’s 93 octane with 10 percent ethanol here in my home state of Georgia. I also use Chevron 93 octane with 10 percent ethanol at times when I’m not close to a Shell station. All the gasoline you listed will probably be okay to run in your SS! I used to run both brands in my 2016 2SS before I bought the ZL1 and the 2016 ran fine!

[hawk02]

The majority of gas sold in the United States contains 10% ethanol by volume.

Stick with a Top Tier gas rated at 91 octane or higher and you'll be fine.

I personally run nothing but Shell V-Power 93 with 10% Ethanol in my Camaro. Chevron would be my preferred alternative but the closest station is 100 miles away so I stick exclusively with Shell.

[Jb54]

Hi: Congrats on your new ride! I can tell you are excited about it! You are fine using 91 octane with 10 percent ethanol. Power loss is minimal. You can always supplement it with a bottle of octane booster off the shelf of your favorite auto parts store, to bump it up .

[appalooza]

I've had my SS 1LE for almost 2 years now and since we don't have 93 octane in Quebec, I always put 91 and the car runs fine. As far as I know, all major banners like Shell, Ultramar, Costco, Petro Canada sell top tier gas. I admit I asked myself the same question when going through the owner's supplement manual..

[Devstrike]

I always use top tier gas on my vehicles I have this list as a bookmark on my phone. https://toptiergas.com/licensed-brands/.


I am a little confused though what does the 1LE do to the 6.2 to require 93 instead of 91 or higher? My manual says 91 or higher should be fine but does not mention possible power loss using 91 over 93. I am the curious type and just looking to learn the differences.

[95 imp]

Also keep in mind that octane requirements drop with altitude....

[Mrbobcat]

I think you should be fine with the 91. I don't know how this engine compares to the 5L in my mustang, but I've had it for over 3.5 years and think I put the recommended premium in it once or twice. The rest of the time I have put in 87 and have been fine. I have never heard a knock and despite what people say about higher octane getting better mileage, I seem to get better on the cheap stuff. Yeah, you might be down a few hp compared to premium but at most that would only be about 1-2% and you will never miss it unless you are going to the track.

[nancygrl]

91 or higher from top tier and you'll be fine, most gas stations here in the states have 10% ethanol so no issues there.....Congrats on your new ride

[TJay74]

Originally Posted by Mrbobcat

I think you should be fine with the 91. I don't know how this engine compares to the 5L in my mustang, but I've had it for over 3.5 years and think I put the recommended premium in it once or twice. The rest of the time I have put in 87 and have been fine. I have never heard a knock and despite what people say about higher octane getting better mileage, I seem to get better on the cheap stuff. Yeah, you might be down a few hp compared to premium but at most that would only be about 1-2% and you will never miss it unless you are going to the track.

That is a great way to damage the engine. Even though you dont "hear" knock doesnt mean it isnt happening. When detonation or knock happens it is akin to taking a ball peen hammer and smacking the tops of the pistons. It can cause damage to the piston, combustion chamber, the valves and the spark plugs.

GM uses 2 main types of timing tables, a low octane and a high octane table. GM also says on the gas door to use 93 octane premium unleaded. There is also a statement in the owners manual that while lower than 91 octane can be used it should only be done in an emergency and as soon as possible 93 should be added back into the tank. Any damage caused by using the incorrect fuel can be put on the owner to pay for as GM doesnt have to warranty engine damage from running incorrect fuel.

Personally I have never understood this mindset, person buys a vehicle that require premium and then runs the cheap stuff.

On the LT1 it will stay in the high octane map as long as there is no detonation/knock events. Once the ECM hears the knock it drops into the low octane map and stays there until the knock event decays out. Then once the event decays out the ECM transitions back into the high octane map.

For me, I run the highest octane I can get at all times.

[ctrlz]

Originally Posted by TJay74

That is a great way to damage the engine. Even though you dont "hear" knock doesnt mean it isnt happening.

Yep. For the knock sensor to sense knocking there has to be knocking in the first place.

My understanding of how this works is the ECM will always try to move back to the high octane fuel settings. It's not like the car knows what kind of gas you are pumping in. The only way it knows to retard timing is by trying to advance it until it knocks again.

[KingLT1]

Originally Posted by TJay74

That is a great way to damage the engine. Even though you dont "hear" knock doesnt mean it isnt happening. When detonation or knock happens it is akin to taking a ball peen hammer and smacking the tops of the pistons. It can cause damage to the piston, combustion chamber, the valves and the spark plugs.

GM uses 2 main types of timing tables, a low octane and a high octane table. GM also says on the gas door to use 93 octane premium unleaded. There is also a statement in the owners manual that while lower than 91 octane can be used it should only be done in an emergency and as soon as possible 93 should be added back into the tank. Any damage caused by using the incorrect fuel can be put on the owner to pay for as GM doesnt have to warranty engine damage from running incorrect fuel.

Personally I have never understood this mindset, person buys a vehicle that require premium and then runs the cheap stuff.

On the LT1 it will stay in the high octane map as long as there is no detonation/knock events. Once the ECM hears the knock it drops into the low octane map and stays there until the knock event decays out. Then once the event decays out the ECM transitions back into the high octane map.

For me, I run the highest octane I can get at all times.

I agree...never understood why somebody would buy a high performance model that requires premium fuel and run low grade fuel in it. Should of bought the V6 if that was the case. There likely isn't a big difference in power between the V6 and LT1 on 87 octane lol.

[SSDan]

OP - I'd stick with Costco for all the reasons you listed - high volume turnover, top tier and the best price. What's not to like with that. I run exclusively Costco but am fortunate they sell 93 octane (with 10% ethanol) here in SC.

There are many US locations where 91 octane is the highest available and all the LT1 engines in those areas seem to run fine for those folks.

Enjoy your new ride!