93 is no cleaner than 87.

+1, seems like the marketing is working

There was a period of time in the 80's when gas prices collapsed that there wasn't much detergents in low grade gas. But I believe that the auto companies kind of pushed for detergents because of greater use of FI.

FROM WHAT I LEARNED THE DIFFERENCES BEING ..

93 BURNS CLEANER THAN 87 ,LESS CARBON BUILD UP

CARS WITH HIGHER COMPRESSION ENGINES REQUIRE PREMIUM ..

Nope, at least for my makes of gas (BP, Shell, Mobil, etc). It burns no cleaner. The only difference is that a higher octane rating has a higher resistance to burn therefore it's often recommended for higher compression motors.

Once Nissan FINALLY introduces direct injection (DI) in the next two years, the need for premium may be a long lost memory. DI allows the engine to run a higher compression (11:1+) without the need for premium plus it tends to make about 20whp more in similiarly configured V6s.

I accidentally prepaid for gas on an 87 only pump in Canada the other day for $20. It ran fine, no difference that I could tell. I ran it for a while, maybe 60 miles, then filled up with 93 for the return trip (about 1/3 87, 2/3 93). 480 miles, I made it about 400 before I refueled, but the light wasn't on yet.

Il Stick To My 93 Octane

You Can Go With Your 87

K Daveb

Good for you, but just be aware the 93 is no cleaner that 87 BP got in big trouble because they were misleading much of the buying public into believing that premium grade was cleaner than 87 or "low grade". BTW, I wouldn't run anything less than 91 in my G because I want all the performance.

The 04 sedan is 20hp less than the coupe. this is why the coupe requires premium and not the sedan. the coupe has been given a higher compression ratio to gain the extra horse power. i ran premium in my sedan for 2 years. i decided to give regular a chance. thats 87 octane apposed to 91. i gained 50-80 km per 60litre tank in the city or about 500 km per tank apposed to 430km with premium. I have noticed no knocking, even under heavy acceleration, (my friend owns an 05 Acura Tl and it has a noticeable knock with regular gas) so i believe it would be noticeable in the G if it was occurring.

I think the added gas mileage proves the car is running more efficient regardless of what the manufacturer recommends. keep in mind the manufacturer will print whatever keeps them furthest away from any legal obligation. and higher octane will never hurt anything so why not say "recommended". Here's a tip, modifying your cars engine for more performance voids your warranty, not putting regular gas in a G sedan. So who does it look like the manufacturer is more worried about harming their engines? Im sure all the mod enthusiast would like to tell the infiniti how their mods are completely safe for the engine but guess what you have underestimated the risk tolerances of the manufacturer.

1) Nice thread resurrection
2) The coupe is "rated" 20hp more than the 03/04 sedans
3) Reality: the 03/04 sedans put down the same power to the wheels as the coupes and 350Zs for that matter. Same exact engines.
4) Premium is recommended by Nissan for the VQ35DE in the 03-06 5AT cars and 03-04 6MT cars. The engine can run safely on lower grades, though performance and mileage may be diminished.
5) Premium is required for the 05-06 6MT "RevUp" cars due to the extended rev range of the motor (7100rpms vs 6600rpms). Higher revs typically result in higher combustion chamber temps which can lead to pre-ignition or detonation.

[QUOTE=
You must use at least 91 octane in the G unless you want to get knocking and risk engine damage. Our engines are made and tuned for at least 91 octane, anything less then you risk damaging the car. Why would buy a 40k car and try to save $3 per tank?[/QUOTE]

coupe drivers should butt out of sedan forums because they are ignorant of our questions. the two engines do not have the exact same specs. ie 20 hp difference. no you can not run regular in a coupe. YES you can run regular in a sedan and it poses no ill risks. the coupe has a higher compression ratio is all.
my sedan gets better gas mileage on regular. took me two years to realize i didnt need to run premium, why because i was reading comments like yours placed in the wrong forums. your 2 cents belongs elsewhere.

knowledge dropped.

I don't now where you get the idea that the coupe has higher compression ratio (you've said it twice), but it's wrong. Coupe and sedan have the exact same engine = same compression ratio.

The difference is the ECU is tuned differently (which is why it requires 91)... If you have a sedan tuned ECU from TechnoSquare you would be required to run 91 too... performance maps with Osiris will require 91 (econo can be tiuned for 87)...

But the engine is exactly the same (year for year).

I routinely get 400-420 per tank on the highway. If I'm on a trip, my AT has no problems making that figure unless it's very windy out.

Both have the same engine, there is no difference in compression ratio. The 20hp rating is largely marketing hype based on the dynos I've seen on this forum and from my car.