91 only - is that for real?

[stangogh]

Hey guys,

I've been totally loving my 07 g35 6mt coupe but like most people my wallet's being killed by the insane gas prices right now. So this brings up this question - I've been filling up my car with 91, like instructed by the cap. This ends up costing $50+ on each fill-up! Some people have been telling me that since it's a lease, I shouldn't even bother and just put 87 since I won't notice the effects in the short term, I just might notice a slight decrease in performance. I've also heard the other side that not putting in the appropriate grade reduces fuel efficiency and in the end will cost me more for gas.

Which one of these views are true? This could save me some serious weekly cash. Also, will I do any harm to the car since I've been driving with 91 for a few months and now switching to another grade?

[G_whizz]

There is huge debate over this and EVERYONE has their opinions on it.

So here's mine.

If the car is leased....I wouldn't worry about using the lower grade Octane. Probably by the time there is any noticeable "damage" such as engine knocking etc... you'll have given the car back and getting a new one. But you WILL lose some performance..if that's not really an issue for you then stick with lower octane. I find the fuel efficiency on my car in particular horrific no matter what grade I use (there is an ongoing fuel testing issue for me right now)

So in short..if you want to save some $$$ and willing to sacrifice the some performance....stay at lower grade. I don't forsee damage happenning anytime soon

[J-Owner]

Just because you lease a car does not mean you can treat the car like crap.

Using the lower octane WILL result in engine pinging. If it does it enough then you will likely have to replace the knock sensor, which might cost you money before your lease is up.

It might also cause you other problems that you may have to come out of pocket for before the lease is up that you otherwise would not have had to spend if you had maintained the car properly.

OR you might have no problems. Too may variables to draw a conclusion.

I can say this, if you can't afford a $40M car and all of the maintenance, gas, etc that goes along with ownership, then you should have bought a luxury sports car.

Just my $0.02. And don't get me wrong, I am not thrilled at all with paying $3 a gallon but I knew what I was getting into when I bought the car so no one to blame but myself.

Conclusion - spend the money for premium and put in the car what it was designed to use.

[leeG35]

Follow the instructions in the owners manual, 93 octane for the Coupe.

While the computer will adjust the timing to compensate for the wrong octane, you performance and mileage will suffer, as well as potentially damaging the engine.
Modified by leeG35 at 5:09 PM 4/13/2007

[mask0425]

stangogh, I agree with G_Whizz that under most circumstances the only difference you'll notice would be on your wallet. Your car's computer is sophisticated enough to adjust for lower octane rating under just about any conditions. Just be reasonable and don't try it when going to Vegas in August with four people and a full trunk of stuff.

Don't know where in LA you live, but if you are anywhere near Westside, you are probably stuck in a traffic most of the time (hey, my 5-mile commute from Beverly Hills to W. Hollywood took exactly 45 minutes the other night and there were NO accidents). Unless you get a chance to open up a car on a regular basis, it is very unlikely to cause any pinging or knocking. Still worried, buy a $5 octane booster from Autozone and carry it in the trunk. May also come in handy if you happen to buy really crappy gas (common occurence in LA and NY). Stay away from ARCO's and unknown brands that typically save money on additives and detergents. Chevron tends to be the best and Valero the cheapest among major brands.

Oh, BTW, whatever you do, do NOT give your dealer any ideas that may void your warranty!!!

[soxx35]

I would stick with the 91 your only spending 3 dollars more a fill the most. You'll get better gas mileage, better performance, and piece of mind using the recommended grade. And if you do want to put octane booster in youll be wasting your money if you put a 5 dollar bottle in you tank but saved 3 at the pump. your still loosing out.

[mask0425]

You'd only need to use the booster if you hear knocking. I have been carrying the same couple of bottles for a few years now. I always try to use the same few gas stations I know are reasonably safe. I have been using the 87 for most of the last 4-5 years in all of our cars unless travelling in a really hot weather. NEVER experienced any pinging or knocking. The thing to keep in mind about the booster is that it's a safety net, not a long-term solution.

FYI, the premium here in Beverly Hills is well over $4/gallon and it's way more than 20 cents more per gallon than regular. I've seen the margin jump to as much as 50 cents during rising gas prices. For comparison, I can buy regular at Valero or Exxon (which I try not to support) in Hollywood area for about $3.20 - 3.25, even cheaper in the Valley or South Bay.

[Andy_V35Sky_350GT]

You guys are seriously using 87 RON fuel in your G35's?

I've only ever used 98 Vortex/V-Power, always been too paranoid to use 91 standard unleaded or 96 standard premium. The 2005 Infiniti manual I have says to use premium only or it will result in engine wear.

[trug35]

Only use 91. The reason being is the compresion ratio of the car, i know the g35 is a 10.somthing/1 ration... anything below 10/1 you can consider using regular but with all of us we will all get severe engine knock if we use regular, if it dosent happen right away, it will

[Q451990]

Using the lower octane WILL result in engine pinging. If it does it enough then you will likely have to replace the knock sensor

The knock sensor is essentially a microphone mounted on the outside of the engine block. The only way you'll destroy it is by overheating it. It won't get worn out "listening" to the knock.

Does the owner's manual really say "Premium fuel only" or does it encourage it saying that performance will degrade? I don't have my copy.

Anyhow, anyone that buys an off-lease car or former loaner car should know that they're getting the next step up from the equivalent of a used motel mattress of the car world (the former rental car) in terms of prior care and maintenance.

I don't think you'll do any immediate damage... but long term it isn't good.

Heath

[paulp]

honestly, i would stick to the 91 octane brothe difference in your pocket isnt even that much

paying for premium gas is part of the package of owning an infiniti

[leeG35]

Here is the gas information directly from the 2007 Coupe Owners Manual.The manual is available for download from Infiniti at http://www.infiniti.com/iapps/techpubs

Note: The Octane rating you see posted on the gas pump is the average of the AKI and Research octane number.

GAS STATION INFORMATION

Use unleaded premium gasoline with an octane rating of at least 91 AKI (Anti-Knock Index) number (Research octane number 96).

If unleaded premium gasoline is not available, unleaded regular gasoline with an octane rating of at least 87 AKI number (Research octane number 91) can be used, but only under the following precautions:

- Have the fuel tank filled only partially with unleaded regular gasoline, and fill up with unleaded premium gasoline as soon as possible.

- Avoid full throttle driving and abrupt acceleration.

However, for maximum vehicle performance, the use of unleaded premium gasoline is recommended.

CAUTION- Using a fuel other than that specified could adversely affect the emission control system, and may also affect the warranty coverage.- Under no circumstances should a leaded gasoline be used, because this will damage the three-way catalyst.- Do not use E-85 fuel in your vehicle. Your vehicle is not designed to run on E-85 fuel. Using E-85 fuel can damage the fuel system components and is not covered by the INFINITI vehicle limited warranty.