Hi, i just recently aquired a 94 LS400... she is a beaut... but, i don't like the fact that the manual says or calls for usage of "premium" gasoline. I wanted to know if anyone has been using an Octane lower than 90... such as 89 which is common in the area where i live. (87,89,93 octane)??? If so, have you had any problems??? I have had cars that called for a octane grade of 91 or higher and have used 89 without causing any problems to the engine, etc. Can anyone help??? Awesome sight... keep up the great work.

 

some higher end cars call for higher octane due to having higher cylinder compression...if you look in your manual, what is the lsited compression?