Do i have to use the 93 premium or can I use the 87 cheap gas in my 91 300zx, I just got it like a week ago

 

I would check my Owner's Manual or my Factory Service Manual. Yours is available at XenonZ32.com Reference

Usually it will give you a minimum octane rating, doesn't say don't use higher. I hear it's not good to use higher... You can use the lowest octane rating that doesn't knock, I would guess.

Let's see what people here think...

Edit: page 9-2 of your '91 Owner's Manual says unleaded premium, octane 91 required.

 

the day i bought the car i put 10 dollars of 87 gas in the car. is it going to stop working?

what do you guys put in your car

 

A higher octane fuel helps keep your engine from knocking or pre detonating, but it wont kill your engine if it does not get it all the time.

Back to back Frequent Oil changes on a new car isn't a bad idea, clean any built up sludge. Do you know the service history of the car ? Do you know when the timing belt and water pump were last changed, normally 60 to 80 K max between changes, less if the car has sat a lot.

 

What PredatorZ said.

Did you notice any knocking while driving on that 87?

Just fill it up with 91 oct and you'll be fine. If you ever find you need gas and no 91 or higher is avail, just put a few gallons of lower octane in and head for a better gas station. Not a problem if you dilute it soon. Otherwise, just listen for the knock!

Edit: My '86s both run great on 87 octane, like the Manual says. Mother Nissan knows best!

 

I always use premium. You gotta treat your car like it's a part of you, otherwise, just when you need it most, it dies on you.

 

Ernie, rocket fuel is available on the black market. (shhhh) and I know where.. but what model are you putting that high octane in?