Infiniti says to use premium unleaded fuel in the G35. Is it recommended or required?

Highly recommended, as your G35 is a high compression engine and lower octane fuel may cause poor performance and in the long run will reduce the life of the engine.

for proper engine respoonse and good fuel economy it is required. but once in awhile of regular wo not hurt.

use premium, the octane rating is a measure of the fuels
ability to resist premature detonation under high compression.

you shelled out big bucks for an Infiniti.. why would you question it?

is it leased or financed? financed yes because it will last longer. Leased-it is not your car anyway.

No its not required! What l do is fill my car half way with 87 Octane, and half with water. It saves me money.

Car makers have 2 designations for premium unleaded useage. The first designation is ''recommended'' & that means the engine computer will change the internal program once the octane sensor recognizes the premium. This will provide the maximum performance. If it says ''premium unleaded required u have to use it. Read ur manual, but it may void the engine is warranty if u don't. In the past, some ''premium required vehicles'' had exhaust systems that ran abnormally hot & this would ruin the system. Check with the 800 number for Infiniti if u do not find it in the manual. Keep in mind that if u get 20 mpg & drive 10000 miles annually, the 20 cents/gallon extra for premium only adds $100 a year to ur budget or $2/week!

Its recommended but you should use it without question because it gives you more miles per gallon and better performance anyway, so it doesnt really set you back that much more than regular.