Shell 91> Ultra 94

Exact same here, no issues with Shell 91.

Shell V-Power 91 all the way. Anything with ethanol is cricket inducing.

I've tried shell 91 a few times but always came back to 94 despite the crickets. I like the bump in power.

How much more expensive is the Ultra 94 over the V-Power 91?

Probably a few bucks..

$3-5 per tank.

In terms of the quality of the gas the Shell V Power 91 (ethanol free) is better than the Petro Canada 94.

They will both be fine for the car.

The best is Chevron 94 (ethanol free) but it's only available out west (vancouver)

Has anyone actually dynoed it to see if they get more power on petro 94 over shell 91 on the stock ECU?

I know I bet slightly better mileage on shell 91 than petro 91 or 94, but don't feel a difference in power. Since ethanol makes less power per given volume and higher octane burns slower, I'd be shocked if the stock tune makes more power on petro 94 over shell 91.

Yes, you'll lose power if you run too low of octane, but if it's not knocking you don't generally gain any power going to a higher octane without adjusting the tune to take advantage of it.

As for difference in cost, it's about 3-5 cents more for 94 over 91 which is about $2 / tank max.

Only use shell 91. Crappy gas mileage though 450 kms/tank on a good day.

I've used Shell V 91 almost exclusively. No crickets. Gas mileage is good in my opinion. I've put in $5 of Petro 91 once, as I ran out and was in a rush, didn't hear the crickets or notice any decrease in perf or mileage, but topped up with Shell shortly after. I'll keep using Shell, as its close to work for me, so I'm good.

I think the best way is so switch.

Use V-91 for a week or a month,

Switch to 94 for a week or a month after, and switch back and see.

Everyone has their own pref.

I personally only use shell now + AirMiles.

I don't know how you guys can compare gas used VS mileage...I use petro 91 all the time and my mileage varies like crazy..Too many factors to even remotely answer in a scientific way lol.

i chose shell soley for the reason that it doesn't put an army of crickets under the hood.

I used Shell, and Petro, and now Costco.

Don't notice a difference per tank. Milage was all roughly the same.