Why does 370z require premium gas?
 

I'm just curious why it is that the 370z requires premium gasoline? I had an '85 300z back in the day and it didn't require premium fuel. I have a Mustang GT right now and it doesn't require premium fuel. Did the 350z require premium? Is it just an aspect of the VQ series of engines?

I'd imagine it has to do with the higher compression. If you use the cheap stuff you could damage your engine or at the very least lose performance and efficiency.

yah, high compression

I agree. :tiphat:

Higher compression requires higher octane. Higher octane gas has a higher ignition point. If you use lower octane gas, it will ignite too soon, thereby causing pinging (pre-ignition).

The mustang GT has high compression as well. However, you will note that it produces a lot less power on anything less than premium. Ford was smart and created a few different tunes in the factory computer. It will retard a bunch of things and happily (but less efficiently) run on lower octane fuel.

Nissan did not (and I don't blame them, if you buy a sports car, you should run premium if it requires it.) do this. It is a high-compression engine and you need to run the recommended octane at minimum.

yeah and i have a 1990 300zx and it also requires premium gas.

most of the japanese and european sport/performance cars require premium. My SR20DET swapped 240 did, my RX8 did, the 350 does, the S2k does.

I like that signature, Thorium! I'm in the same boat.

Thanks for the education, Z-owners!

at least premium isn't expensive as it was a couple of years ago when it took like $80 to fill up... :ugh2:

It's a whopping $0.20-0.30 a gallon more, for around 10whp or so (according to Ford, the mustang GT gets 412bhp on 91* and on 87* it gets 10bhp less, and 13#tq less). If you get 20mpg and drive 15K miles a year, that is about $200 a year for 10hp/13tq mod. A VERY! cost-effective mod in my book! You would have to put 25K miles or so on the vehicle to equal a cat-back in price, and this involves NO work and NO chance of voiding a warranty.

According to Ford, the mustang goes from 412 hp to 405 hp when changing from 91 to 87 octane.

402.

Besides, the way people talk about mods/hp gains for Z's on this site, 10hp/13tq is a LOT!

Further, the 91* tune that Ford uses is VERY conservative. People are getting a lot from just a tune on that car. I doubt Nissan is being nearly that conservative on their 332bhp V6.

i get 93 octance here in NJ, maybe thats why my Z pulled hard lol

As long as you aren't getting KR, then the lower the octane the better.