What type of gas do I use?

Hello, If the vehicle calls for premium, premium should be used. Look inside the lid to the fuel tank, and see if it notes an actane rating. If you still have the owner's manual, you can find that information under 'fueling' or 'fuel type'. Also, look near the fuel gauge on the dashboard, and see if it says regular unleaded only or premium unleaded only. Be advised, too low of a grade of fuel can lead to issues after a few thousand miles, and is highly recommended against. However, if the engine is made for low (87-89 octane), this fuel will work just fine.

Your 1999 Infiniti I30 requires a minimum of 91 octane per the manufacturer. Anything above that is also ok. If you use a fuel with less than that it will effect your performance & gas mileage and could lead to carbon build-up in the engine. At 90,000 miles, you should consider getting a professional fuel system cleaning & de-carbonizing (every 30,000 miles). Please call with any questions or to schedule an appointment 847-352-2886.

I agree owners manual is the best reference, If you are having problems give A&R a call to resolve rough running and check engine light issues 630 834 6790