recently read an article saying that for most vehicles regular gas is just as good premium and will not damage vehicle. Is this the case for G35 coupes ? Most of my driving is highway driving where I don't really care about max performance.

 

For "most cars" -- meaning the cars that specify regular in the owner's manual.

"Most cars" are tuned for 87 octane. Higher octane fuels do not have more power in them, they resist pre-detonation better (meaning you can use higher compression rations and more advanced engine timing without the engine knocking.) Most cars won't take advantage of the higher octane.

Cars with high-performance engines are tuned for higher-octane fuels, and generally recommend them. They run more efficiently on the premium gas than on the regular, as with the regular gas, the anti-knock sensors kick in and retard timing, which both reduces power and fuel economy.

The G35 Sedan can handle 87 octane, though you don't save money - as fuel economy suffers just about enough to offset the cost difference. The G35 Coupe has more aggressive engine timings, and can't handle the lower octanes for any length of time. The owner's manual specifically says that, for the coupe, don't go below 91 octane unless you have no choice.. and if you have to, put in as little as possible, and then fill up with higher-octane fuel as soon as you can. I've seen someone report in the Coupe forum that they filled their tank with regular gas, and by the time they got down to a 1/4 tank, the engine was starting to run really bad. A tank of premium cured the problem.

Short Answer: No, you need premium, and even if you could run regular, it wouldn't save you any money.

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter

 

Agreed. Though it's a waste of money to run a car designed for 87 octane on premium (>91), follow the owner's manual for the suggested fuel. The G35 is designed for premium gas. You might get away with lower octane fuel for a short time as the computer will retard the advance to compensate, but you'll also get a corresponding decrease in HP and gas mileage.
It takes a very astute driver to feel/hear subtle engine knock that will eventually cause damage. If you're lucky the knock might only crack the ceramics on the spark plugs, or it can cause fissures in the pistons and cylinder walls.

<font color=green>GG</font color=green>

 

the G35 coupe requires 91 is becuz of their rated 280HP

but who drives a G35 and fill up with regular anywayz??? even sedan owners fill up with premium!

 

RIGHT ON ryoken & gordgee

<font color=blue>[b]G35c DG/leather 5AT 18"wheels Tint.... The car in your mirror will fade quickly

 

You bought a G35. Don't be cheap on gas, besides, prices are going down!! YAY!! [img]/w3timages/icons/smile.gif[/img]


It's still a G thang!!

 

OK ... I agree totally ...no regular or mid grade etc...

what about a octane booster in the can or some higher octane like sunoco 94 etc

???

later g's

 

Going higher than the recommended octane won't necessarily give you any benefits with out further tuning of the engine and ECU. It's cheaper to just fill with the premium of your choice than to use a can of octane booster.

<font color=green>GG</font color=green>

 

Hey guys, read this thread. It's very interesting. Seems the higher octanes (above 91) just might give a little more performance after all.
ECU Reprogram

<font color=green>GSM</font color=green>

 

Well, if you reprogram your ECU, yes. With the stock engine computer, no (or at least not very much). Reprogramming your ECU (along with other mods) might also raise your minimum required octane rating above 91.

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter