It May Be OK to Use Regular Gas Instead of Premium
The company has compiled a list of the cars and trucks made over the past four model years that separate those for which premium is required (over 1,500 makes and models) and those in which premium is recommended (over 700 makes and models). Those in which premium is recommended are candidates to run on regular fuel. In other words, you have about a one in three chance of being able to switch to regular without harming your vehicle.
What difference in performance should you expect? According to the two, you might not accelerate quite as briskly, but shouldn't experience engine knock, the sign that the octane is not up to snuff.
For more gas-saving tips, read How to Save on Gas as Prices at the Pump Climb.