Use exactly what your owner's manual lists. Using a higher octane than your engine was designed to burn, will provide no benefit whatsoever. No more power, no better mileage, and in fact can provide poor starting, and in some cases, harm the engine. Besides the fact you are paying more for high octane fuel you do not need. Using a lower than required octane can cause less power and pinging. This can eventually do damage to your engine. It is a myth that a higher octane fuel provides any benefit to an engine not designed to use the higher octane.
87 octane is sufficient.
It is 91 times 87 = 7,917
91
87/91 is in its simplest form.
87
i found with mine, that if you used 91 octane you get worse gas mileage than with 87, you also have to remember the KZ models are old and when they were running the streets the most common gas was 87 octane 91 was pretty much race fuel. so if you want better mileage i would probably go with 87.
Not really. Fill up with the "correct" octane when you run some fuel out of your ride.
87 should be sufficient and it will run on 87 but if you want the full potential of this engine then Cadillac recommends 91 octane premium fuel.
the 12 runns fine on 87. the 6 needs hi test.
no problem as long as it is unlead gas,i filled up with my 2002 qx4 and find no big difference as the 91 premium gas.
regular 87 is fine. if it is a gs-r you want to put premium at least 91 octane
Regular unleaded. 87, 89, and 91 will all work just fine. Although the 91 would be your best choice since it burns cleaner and better.