Exactly. This is also the first time I've heard that premium is REQUIRED for the 03/04 coupes (all) and 05/06 5AT coupes. I could have sworn the owner manual for those cars recommends premium for maximum performance, but lower grades can be used if needed, but performance may be slightly diminished.

 

Just did a little research on this site and apparently the 03/04 coupe owner's manual basically says the same thing as the sedans. The difference is they say something along the things that premium is "required" for maximum performance, but the car can be run on lower grades. I wonder if the difference in recommended (sedan) and required (coupe) is how Nissan played the HP numbers game with these cars? Running 87 octane in these cars would likely result in a reduction of about 5% to 7% power. For a 280hp car (actually rerated to 275hp in 07), that would mean 260hp to 266hp on 87. Hmmmmm......

 

I googled mpg and found a site where I can select my car and year and it actually got fewer miles per gallon with premium gas?! 0_0 I use 87 sometimes but usually 93! Also since Im getting close to 150k I started running a lucus treatment!.

 

I've gotten over 400 miles to a tank...
Ive also almost got under 300 one time.

I can get around 24-25 mpg on a smooth flat highway. I get 17mpg on my daily commute. It seems the car takes a lot of gas to get going, but doesnt use much to keep going ("use much" is a relative term).

 

I rarely ever get LESS than 400 miles a tank. 6 sp stick and 50/50 highway/city. I try to drive reasonable. I have gotten over 500 miles a tank -pure highway. that was with the orig tire size 215/55/17. With larger tires (and extra weight and footprint size), mileage goes down.

 

+1, I thought I was the only one that did this

in cool months I run mid grade which is 89 here
in the summer months it gets over 100 and I run premium, which is 93 here

I have never heard any ping in my car with mid grade, but I figure when it is hot it is worth the $2/tank for the extra safety..

 

Sorry to revive an old thread, guys, but I've got a question for the experts on here.

I drive an '06 G35 sedan (stock) and to date have been using primarily 94 octane gas on my G. Most of the gas stations in my area (Vancouver and fraser valley, BC) carry 91 octane gas with up to 10% ethanol. The 94 octane that I can get at a specific chain, however, carry the 94 octane with NO ETHANOL at all. And the only reason I use the 94 octane gas is because someone once told me that ethanol is not good for my engine.

My questions are thus: 1) is it useful to go beyond 91 octane for my G in terms of protecting the engine, or should I have stuck only with 91 octane like the manual said?, and 2) should I avoid ethanol-enriched gasoline?

Thanks!

 

Better gas mileage or not, stick with 91+. The higher octane helps prevent knocking in high performance motors. Anything less may be harmful to the motor. Everybody worries about using oem fluids for transmission, and good oils, etc... why ignore gas recommendations?

I've gotten more than 400 per tank before. It doesn't happen when I mash on the gas or through regular daily driving from light to light, but it does happen on those road long trips that sees tons of freeway.

 

i used 91 octane which is the highest in cali from the beginning..switched to 87 octane after i realized that premium is only recommended and not required on the sedans..also talked to some friends with the same car who used 87 octane..i think i switched to 87 octane at 50k miles..my car now has 81k and has had no problems..mpg still sucks !

 

I ran 87 octane in my 06 sedan on the way back from picking it up (800 mile drive) it runs fine but moving off from a standstill at lower rpm's it cackles.

 

I have an 04' G35X and with a light foot, mostly highway, and lots of downhill runs only ended up with about 368 miles for the tank. That was from a complete fill up (neck and all) to stuttering on the road with the gas light on. That was the best mileage I ever got from my G.....

 

That's strange from a full tank down to a little above quarter tank I was over 420miles next time I fill up I'll bring it down to till the gas light comes on and see how many miles I get.

 

Wow! Sure you don't have a G25?
I never get that kind of range or mileage.

 

I get that 440 mile range too. I run 89 octane in CA.

 

I've made the change from 93 octane to 89 octane recently. No difference in fuel ecomony. I drive 95% highway so i'm still seeing nearly 400 miles per tank. I routinely drive 100-130 miles of sustained 65-75MPH frequently.