I have a 2023 C8 and have been filling 94 Octane gas at Petro Canada so far. Upon further researching I have learnt that almost all gas in Ontario now has Ethanol. I called Shell and they said that their Nitro V-Power 93 Octane has only 5% Ethanol. Planning to switch to Shell as they are Top tier rated and that is recommended in the manual . What are others using and is there a recommendation on what to use before putting it away for winter? Any opinions on Costco Gas which is also rated as TopTier. Appreciate the insight.
What gas to use?
- Thread starter kvette23
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Almost all fuel in Canada has up to 10% ethanol. Personally I think its good for an engine and have been using E10 or "gasohol" since 1985 in cars and motorcycles and have had excellent results. In the late 80s there were a lot of myths regarding E10 but while those have been debunked, many still persist.
Currently, my closest gas station that carries high octane is Shell and it has PON 93. I notice the new manual (2023) lists the C8 as being OK with PON91, probably because in California PON91 is the highest octane and that's a big market.
For storage, I fill the tank and use Sta-Bil fuel stabilizer or the Canadian tire version. My storage routine is wash, pour in Sta-Bil, drive to gas station (its close) and then drive home. I remove a lead from battery (no electrical outlet) and then cover the car. Thats it.
Currently, my closest gas station that carries high octane is Shell and it has PON 93. I notice the new manual (2023) lists the C8 as being OK with PON91, probably because in California PON91 is the highest octane and that's a big market.
For storage, I fill the tank and use Sta-Bil fuel stabilizer or the Canadian tire version. My storage routine is wash, pour in Sta-Bil, drive to gas station (its close) and then drive home. I remove a lead from battery (no electrical outlet) and then cover the car. Thats it.
DenisC8
Power User
octane rating of pure ethanol is 100, but when it's blended with gasoline, it performs as if it's 112. In other words, higher-octane blends — Petro Canada's 94 and Esso's 93 — use more ethanol, not less. Performance engines perform better with ethanol.
Ethanol is extremely hard on rubber! There is little rubber in new cars these days, but for tractor, go-kart and other small engine carbs Ethanol is a killer!
For my cars I just go to C.T. for the points. Remember that Octane fights knock. High compression engines require higher octane and today's cars don't have as high compression as they used to. Plus they have computers that will listen for knock and detune when required. For daily driving use whatever gas you want to.
Edit: I forgot to mention that the ambient temperature of the incoming air is important to fight knock. The hotter the more prone an engine is to knock. The cooler the air the less likely. So in winter all cars will run fine on regular gas.
For my cars I just go to C.T. for the points. Remember that Octane fights knock. High compression engines require higher octane and today's cars don't have as high compression as they used to. Plus they have computers that will listen for knock and detune when required. For daily driving use whatever gas you want to.
Edit: I forgot to mention that the ambient temperature of the incoming air is important to fight knock. The hotter the more prone an engine is to knock. The cooler the air the less likely. So in winter all cars will run fine on regular gas.
Ditto on what everyone else is saying. It's difficult to get away from ethanol these days in Canada.
I always run my snowblower completely dry at the end of the season, but in my cars, I just put top tier gas and stabilizer.
CTC is Imperial Oil for now. They lost the contract to Suncor if I remember correctly.
Costco uses a combination of all the big guys (Shell, Suncor, Imperial), so you never know who's molecule you are using.
A C8 has a high compression ratio of 11.5 or so...But I've never noticed any issues with 91 octane or higher. Start playing with 87, and it might feel a bit jerky as the engine adjusts timing.
I always run my snowblower completely dry at the end of the season, but in my cars, I just put top tier gas and stabilizer.
CTC is Imperial Oil for now. They lost the contract to Suncor if I remember correctly.
Costco uses a combination of all the big guys (Shell, Suncor, Imperial), so you never know who's molecule you are using.
A C8 has a high compression ratio of 11.5 or so...But I've never noticed any issues with 91 octane or higher. Start playing with 87, and it might feel a bit jerky as the engine adjusts timing.
The old LS3 was at 10.9. Then GM went high pressure direct injection to get a bit more power out of similar architecture. They pushed the LT2 as far as they could while maintaining reliability.
I've put 91 in my car many times when 94 isn't an option and haven't noticed any difference at all.
I was using non ethanol 91 from C.T. and still use their 91 now that it has up to 10% ethanol. I found no difference, but likely wouldn't anyway! lol
You would really have to stomp on it at higher altitude and hot outside temps to need higher than 91.
Need to reexamine a few statements here:
Pure ethanol octane rating varies but typically is 113 PON (Pump Octane Number)
Iso-octane what is used as an indicator and is designated 100 and thats why we call it an "octane rating".
If I am trying to produce Regular (PON87), I can blend for 85, add up to 10% ethanol and end up with a 87 so less refining ie less production cost. There is a restriction on (and fine for) going over 10% ethanol so its not really E10 and more like E8-9. For example blending an 85 with E8 is 85x92 +113x8 = 87.24 so within PON 87 spec.
Although Renewable Fuel Regulations stipulated fuel retailers must use a minimum of 5% ethanol, that is based on total volume so a fuel marketer could decide that both of their grades get 5% or regular grade get 6-7% and "premium" get none and that was common. Now however both grades get some ethanol.
Regular is about 88% of fuel sales while Premium is about 11% and mid (a pump blend) is about 1.2% so if I were a fuel marketer, I would put the allowable maximum ethanol in Regular and none in the PON91.That way I am maximizing profit while not getting busted for regulation breach and then advertise PON 91 as "ethanol free" for the skeptics who are willing to pay more for myths.
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follow the Owners Manual, and for the C8, it calls for 91, unlike the C7 Owners manual, it calls for 93, so that's what I did for both my C7, and now C8, No issues...
Not according to my manual
Fuel
Unleaded gasoline, rated at 93 octane or higher, is required.
Yes but Murray's is a 2020. Totally different engine than the 2023.... errrrr What.......?
very interesting debate - I just thought putting in high test was the best option. Despite it being almost 2 bucks a liter - I fill my fuel cans with high test for anything around the farm which is gas, everything else is diesel so its never been an issue and everything runs like a champ. Thankfully I do actually fill up at Shell which is the closest gas station to me in the booneys. I must say though here we are talking about putting our cars away - sad time of year!
As I pointed out in Post #2, the C8 originally required PON93 or higher. Unfortunately California has a limit on octane rating of 91 so that let out a huge market. So GM changed the fuel requirement for 2023. The change is likely just software (fuel mapping) so no need to change anything in the actual engine. I don't think it was an OTA so if you are pre-2023 I would stick with PON93
not sure what manual you have, but it's pretty clear in mine....2023 Corvette...
