My father-in-law claims it does but I can't find anything online that supports this theory. Thanks.

 

No.

It's an octane thing to match advanced ignition timing while avoiding detonation. It has nothing to do with longevity, cleanness, etc.

Rocket scientist Dr. Bill Wattenburg has debunked the premium myth over and over. Unless your ECU/timing is set up to take advantage of the higher 93 octane, it is a complete waste of money.

 

Awesome answer, thanks.

 

It could increase your engine life if it prevented detonation, because detonation is bad . . . but like Charliehorse said, that should not happen unless the engine is tuned for the high octane in the first place.

Also most "premium" fuels (supposedly) have higher levels of additives such as detergents -- so that could possibly contribute to longer engine life. But that really has nothing to do with octane; it is just a coincidence that the "premium" fuel has the "better" additives, and it is also has higher octane.

 

It can also cause deposits if your timing isn't advanced because higher octane requires higher temp to fully combust

 

That part has been refuted.

 

This was once true but not anymore. Shell was using different additives in its V-Power premium fuel as recently as 2007 but now even they use the same additives in all grades. At one time, Amoco Ultimate premium fuel was refined differently to make it completely clear (most gasoline is a sort of amber color). The difference was never proven to be beneficial but it was a great marketing tool. However, after BP took over Amoco, they stopped marketing Amoco Ultimate when they came out with their "Invigorate" product in all grades in 2008.