The engine will retard ignition timing and you will have about 15 less horsepower, best case scenario. Worse case scenario you will get some mild pre-detonation that will damage your engine over time.I put 90 octane in my $3000 used Volvo because that is what it's supposed to use, if you can afford a TL you can afford to put the gasoline in it that it's designed to use. Don't be such a tightwad. LOL