My Opinion!!  Every vehicle will run on 87 octane, yet making our engines burn the cleanest and the most efficient is the bigger picture. Making our vehicles more efficient not only helps with our atmosphere to allow us to breathe, it also creates better gas mileage for your vehicle. Burning 87 in higher compression and Turbos will cause carbon build up very quickly causing some major problems in you vehicles performance. Excessive carbon built up cause’s hard start, hesitation and misfiring. Fixing these issues can be very costly. So, here my recommendations, All 4 cylinder non-turbo motors use 87 octane, all non-turbo 6 cylinder engines use 89 Octane and all other engines use 93 octane. This will cost anywhere from $2-5 more per tank full yet remember, making you vehicle more efficient will greatly reduce Carbon over time, and an a efficient burning engine will get you better gas mileage. Both reducing maintenance cost to you and less time at the gas stations.