daryn67

I have been using premium or 93 Octane Fuel for my Newly purchased G37s Convertible. I'm being told by some that as long as I go to reputable fuel places that use good additives such as Costco, Valero, Shell, Exxon, Mobil Etc. that using the lower grade of Fuel will work fine for this car. As fuel prices go up recently, I'm wondering if stepping down a step on fuel would cause future problems with these performance type cars. I know to avoid no name fuel depots or places like Sam's club who don't advertise these extra additives in their fuels.

I would appreciate peoples thoughts or opinion of this as I don't want to go cheap on this car if it hurts the life or performance of this car I hope to keep for years to come.

Love my G!

slartibartfast

iTrader: (7)

Your engine will safely operate with lower octane fuel. Of course, you no longer have a 328 -hp engine...

saywat?

iTrader: (3)

id go by this

blnewt

iTrader: (13)

91 is the highest we have, been running it since our G35 back in 07 through 90k miles on our current 09, and if I can get lucky and find a non-ethanol station I can get over 30 mpg easily on the hwy. Our last road trip got up to 32 mpg and no shortage of power for sure.

Ricio1991

Use nothing but premium, I never use unleaded for the last 3 years and two g37's

Crazyirish

Where are you getting leaded fuel?

crookncastle

the lower the octane rating the more unstable the fuel is during combustion. in high compression engines it can result in pinging or piston slap noises during cold starts or under hard acceleration. lets just say being cheap can end up costing you in other areas.

stealthee

NO idea what fuel costs in your area, but lets do a little math lesson here.

Lets assume premium is $2.75 and 89 is $2.55.

Now lets assume you run the tank completely dry. The cost to full the tank with premium is $55. The cost to fill the tank with mid grade is $51.

Is $4 really that much money? If it is, then you bought the wrong car.

telcoman

I love my G37S also but I won't pay the additional $.50/gal in New Jersey for premium.
I'm on my second G and put 171796 miles on my previous 06 G35 6 speed all with using regular 87 octane. I did try one month of 91 octane and one month of 93 octane mainly because of so much misinformation on octane use on this and other forums. My mileage did not improve nor did performance . I returned to using regular 87 octane and my present 2012 G37S has never seen a drop of premium. Locally I fill up at my local WaWa station.



I recently filled up in NJ and drove 293 miles to Virginia. Filled up at a Loves Travel plaza with 10.754 gallons giving me a 27.35 MPG.

Telcoman

Lego_Maniac

iTrader: (3)

+1

I suspect that if you're the type of driver who keeps the revs under ~4500 or so, you'll never notice a difference.

jfisher

Standard fuel is $.50 cheaper so double your figure. I usually fill up 17 gallons at each fill up so the difference is $8.50 per fill up. I fill up about twice per week so we're talking $17 per week or $884 per year. Big difference and adds up quick. I rarely beat on the car and I notice zero difference when daily driving.

JSolo

iTrader: (14)

That is key right there. Driven mildly, there's likely little benefit to premium. Driven hard, premium or bust. I remember trying regular in my bike. It would run ok until about 6Krpm. Then the pinging would begin. Now mind you, redline was around 11,5. It would often see 10-11K the way I rode it.

On a road trip, if slabbing it for great distances, sure, 87 is fine. But there better be 93 in there when we hit the twisties. I don't go up to redline, but 6/6500 is common in the G. Car really starts coming alive after ~4500.

saywat?

iTrader: (3)

anyone know if coupe and sedans are tuned differently? would a coupe see more cons going with lower octane fuel than a sedan?

Lego_Maniac

iTrader: (3)

Nope. The exhaust/muffler routing is the only difference.

saywat?

iTrader: (3)

hey telecomman so when u drive fast and accelerate hard u dont notice anything? or is ur experience based on driving like a grandma? im being serious not trying to make fun of u or anything