I use shell 91 for any vehicle that has high performance aspirations, or might be sitting for longer periods. The reason is that is does not contain ethanol, which can gum things up, and can eat rubber parts, esp on older cars.
Petro Canada has ultra 94, which contains ethanol, so I don’t touch the stuff.
Any modern car can compensate for fuels of lower octane rating.
I once experimented on my XC70. With the cheapest Shell it would do 0-100 in 9.5. With 91, 7.5 seconds. In normal driving, I couldn’t tell the difference.
- This reply was modified 2 years, 2 months ago by ottom.