hey guys, so my Lexus I acquired has 88,706 miles on it currently. I have no records if the previous owners used premium fuel or not, but I highly doubt they did. and the car salesman that sold me the car and filled up my tank said they've only used regular...so my question is should I just stick with regular gasoline or start using premium? thanks for the help!

 

For sure only premium. The computer will probably retard the timing but I would not count on it long term. Maybe just one fill up would be fine.

Also if you have a 16-17 GS 350 check out my vid on my channel and see if you have the chirp.

IMO - Run this tank, take it easy on the pedal and fill up only with premium from now and on.

 

As a kid working at several dealerships all they had was one gas pump, regular. I’ve never seen a “record” of the type of fuel used in any car. I’ll stick with what the manufacturers recommend. Don’t want any valve problems with low grade fuel.

 

The altitude can be your friend. At sea level with dense air premium is needed. At 5000 feet you can easily use regular. Anyone living at higher altitude can tell you that at sea level its a different car.

 

Almost every member here will tell you to use premium because that's what the owner's manual calls for.
You'll be alright.
You won't notice much.

 

I like to stay off the knock sensors as much as possible, 91 or 93 is the way to go.