110 octane safe?

[PKRWUD]

Your friend needs to go back to school. Octane is what slows down a gasolines burn rate. Higher octane = slower burn. For optimum performance, you should use the LOWEST octane you can operate safely with. In otherwords, if it doesn't ever ping or detonate with 91 octane, try using 89. If it still doesn't ping, try 87. If it still never pings, you're good to go. The ONLY reason to use a higher octane gasoline is because you have modified the engine to the point where your current octane allows pinging under adverse conditions. Advancing the timing and increasing the compression both usually require the use of a higher than normal octane, but you still should use as low an octane as possible. High octane gasoline has a false reputation of increasing power by itself. This is not only false, but it will actually slow you down. Gasoline companies give their high octane grade names like "High Performance" to increase sales. The truth is that fast cars use high octane gas, but it's the engine mods that require the high octane, and that make the car fast, not the high octane gas itself.

Will 110 octane gas hurt your engine? Not really, but unless your engine is very modified, it will slow it down, and it will eventually leave unburned deposits.

Tell your friend to just leave his emergency brake lightly applied instead. It will have the same effect on performance, and save him a ton of money.

Take care,
-Chris