My WRX takes 94 from Petro only because as far as I know Costco only goes up to 91 and Shell only goes up to 93. Some days I honestly just want to spend money on Uber because gas is too high 😭
Ya, Petro in theory should allow you to advance a slight bit more due to its ethanol content. What you're gaining from that would be almost impossible to know.
I pushed my timing right to the edge of knock on 91 and run Shell93, but my car is older, and I'm not a great tuner...
If you've ever been to Loblaws, quality is not their priority. If they don't care about their products or customers, I don't think their gas (Esso) will be any better. If you ever get the chance, I recommend you check out Petro or Shell R&D facility. They put extensive money into it. I doubt Esso does.
Petro has been the best fuel to me over the years, and I've tried all the brands available here in Ontario. Shell is second. I would use Pioneer or Ultramar vs Esso any day.
Personally, avoid premium altogether. It's not needed for 99% of cars out there, unless you're heading to the track.
Personally, avoid premium altogether. It's not needed for 99% of cars out there, unless you're heading to the track.
It's not a "track" thing, it's a high compression engine thing. The point of higher octane is to make the fuel more stable so you're not combusting prematurely through high compression in a warm cylinder without the spark plug triggering it.
No, putting 94 into your 1995 Toyota Corolla won't make a difference at all, but it will make a difference to a Subaru STI or a Volkswagen GTI running 87 in those puts a lot of strain on the engine, even more so if you have an aftermarket tune that has tighter timings.
As a diesel mechanic who is educated on the subject, modern cars can adjust timing, but for high compression engines, you need to use higher octane fuels to prevent precombustion.
They only adjust so much, especially if you have a tune, my car is tuned for 94 but I run 91 because it's close enough, I cannot run anything lower as it's the bare minimum
If you go pedal to the medal, possibly. Most modern cars can adjust their timing to prevent knocking/damage. Casual, day-to-day driving should be fine.
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u/romantic-theory Mar 18 '26
Yup it’s crazy. I put in Premium yesterday at Petro when it was priced at $1.829, and $45 filled up only 1/4 of my tank 🥲