There have been previous articles which speak directly on this subject.

Is it true that cars which say 91 or 93 octane will run on 87 octane? Yes, that is true.

What is missing from the article is the following facts.

A car designed to run on 91 or 93 will not perform as well on 87 octane. This means you will get better gas mileage with a higher octane fuel up to at least your recommended octane level.

Also, running a lower octane will cause problems to your vehicle over time which will in the end cost $.

If you add up the higher mile per gallon you receive and the cost savings of not damaging your car, the costs saved by using a lower octane fuel in the end are about even.

So, let’s see pay a little less for 87 octane and get a lower mpg return and cause problems to my car over time?… or simply pay more for the recommended octane and avoid those downfalls?

The choice is simple.

The fun part if you can actually test out the mpg part based on the octane you put in your car. The longer term affects wear and tear on the car would take much longer to prove/disprove on your own.