which grade fuel in 2006 M35?

[keithhr]

I just purchased a gorgeous 2006 M35 and while coming home I needed gas and without thinking I filled it up with regular 87 octane gas. I read the manual and it lists several engines some requiring premium. Have I done something bad? What grade of fuel does it require, I thought the salesman said it was ok with regular, I hope?

[keithhr]

I hope someone can help me with this

[antzrus]

According to the manual, "regular" is fine for the '06 M35. But for better performance they recommend "premium." Relax-enjoy your gorgeous machine!!

[keithhr]

thanks Jim, I was able to find the engine number used in the M35 and thus in the manual. This is by far the nicest car I've owned, I'm glad that I discovered this somewhat underpriced gem.

[ghstudio]

I had an 06 M35 and now an 08 M35. I burn regular only with no problems and I try to buy gas without ethanol which gives about 10% better MPG.

You filled the car with the right grade of fuel.

[NightRiderQ45]

I had an 06 M35 and now an 08 M35. I burn regular only with no problems and I try to buy gas without ethanol which gives about 10% better MPG.

You filled the car with the right grade of fuel.

Dang, you all are lucky. I thought this car required premium. Does the 03/04 require premium. My Q requires premium.

[szh]

Dang, you all are lucky. I thought this car required premium. Does the 03/04 require premium. My Q requires premium.

The M35 allows use of non-premium, although premium is recommended. The M45 does not allow this ... even in the newer ones (i.e., not just the 2003 and 2004 M45 models) premium is required.

Z

[NightRiderQ45]

The M35 allows use of non-premium, although premium is recommended. The M45 does not allow this ... even in the newer ones (i.e., not just the 2003 and 2004 M45 models) premium is required.

Z

See that's what I don't understand. The M35 is the same as the M45 minus the V8...so why does the M35 allow use of non premium but the M45 requires premium? Other than the V8 what makes the M45 the car that requires premium?

[szh]

See that's what I don't understand. The M35 is the same as the M45 minus the V8...so why does the M35 allow use of non premium but the M45 requires premium? Other than the V8 what makes the M45 the car that requires premium?

I have no idea.

Perhaps the programming in the ECU? Maybe the M45 does not make its horse-power rating without premium? I do know that the ring tolerances are looser on this 4.5 V8 compared to the old Q45 engines ... and this does lead to oil "burning" and carbon build-up. Maybe, Infiniti felt that the problem would be exacerbated with non-premium?

These are just guesses.

Z

[paulc]

If you look up octane rating in wikipedia you will find the following explanation:

The octane rating is a measure of the resistance of gasoline and other fuels to detonation (engine knocking) in spark-ignition internal combustion engines. High-performance engines typically have higher compression ratios and are therefore more prone to detonation, so they require higher octane fuel. A lower-performance engine will not generally perform better with high-octane fuel, since the compression ratio is fixed by the engine design.

Bottom line is that higher compression engines need higher octane fuel but higher octane fuel will not make your car run better or faster if it was design to run on low octane fuel.

[Goodspeed91]

Premium fuel is required in the M45 because of the bore size and the whole intake manifold. I pumped 87 for a week and started hearing knocking noises. Dealer asked me what I pump and I said 87. Well a whole engine rebore and a week later my car is good as new. The 87 octane apparently doesnt meet the requirements and dlesnt burn as clean. Thus leading to carbon build up and premuture oil burning. The knocking you hear is the carbon deposits hitting the hot cylinder walls as is "melts" away. You should be fine with 87 octane in your M35. Change your oil regularly and air filter and your car will stay just as nice as it came off the lot. Good luck with your new car!!

[PAdutchKorean]

Wait a minute! I've owned my M35 for about 2 years now. YOu mean I could've been pumping regular this whole time?

Dang.... Is it cool to switch over now?

[PAdutchKorean]

Wait a minute! I've owned my M35 for about 2 years now. YOu mean I could've been pumping regular this whole time?

Dang.... Is it cool to switch over now?

[macgiver]

mac here , sort of a joke but probably an accurate yardstick (don't know your expenses !) , if you make over 65k/yr ??
Use the PREMIUM .??

[EdBwoy]

I know the original thread is almost a decade old, but I think it's pretty relevant even today.
IMO, for a car whose manufacturer decided and also wrote inside the fuel door that premium is recommended although regular is OK too...

1. You might want to track your performance, for example by mpg before fully abandoning premium.
Use regular, performance drops, your car has to work harder for the same output, burns more fuel.
Use premium, car is at optimum performance, you don't use as much fuel but it costs more per gallon.
YMMV, so test it out, calculate and let us know how much savings you realize at the pump.

2. Idk how practical the rule of thumb on income plays, but these cars have become pretty cheap by 2017.
Not the V6, but I bought my first M45 while still in college but even then I never even thought of using anything other than premium

[macgiver]

mac , EbBwoy - right-on boooooooyyyyyyy !!!!!!

[dstreamer]

Hi friends.

Something I noticed on both my infinities

1. 2010 M35 S
2. 2002 QX4

Is that although premium 91 provides a smoother acceleration and drive as well as idling. 87 regular gives me better gas mileage.
22 mpg (87), 20mpg (91)

One more thing I noticed is that idling is a little more rough with regular 87 as compared to 91.

I think you are safe to use either. The manual says 91 is recommended but 87 is fine too at the loss of performance.

[macgiver]

Premium = 91 Octane ( have seen 92,93,94,95 ,latter two E. coast 15 yrs ago) . Regular =87 Octane (have seen 86) .
Tis a HUGE STEP DOWN any of those Prem. grades to REGULAR ! !!?? I don't see one instance of anyone above talking a sensible downgrade like MID-GRADE = 89 Octane ?? Hate to say it shall we just p&%$#@#$% on our cars to wash them?? This folks is a perfect example how not to allow your vehicle to acheive longevity - along with the idiotic 10k or 15k mi oil changes - have at it .Save pennies

[Larz]

In my state (Florida) the only options for gasoline are 87, 89, or 93. I have NEVER used anything other than 93. I am sure there are those who can honestly say they only use 89 and have had no issues. I've been told that in a pinch, you may temporarily use a lower grade but you should return to 93 soon as you can.
I am also aware that the computer can make adjustments based on the fuel being used any given time. However, even if in my own mind, the use of lower grades is not how the engine was designed to be run.
My recommendation .... you knew the thing requires high octane when you decided to buy it. Nobody provided you with documentation that the fuel grade was optional. If you decide to save some money by using lower grade fuel, actually DO save that difference in a safe place and do NOT spend it ... ever. That little piggy bank may be of some help if/when you get a big repair bill for that engine.

[macgiver]

A most significant factor in deciding when/if the decision to use the "option" of a lower than specified Octane grade of gasoline ("option' of course meaning that the car is in fact designed , how well ,who knows, to SATISFACTORILY deal with handling a lowered Detonation curve!). HEAT is the killer situation here , for I,yes have used Mid (89) in my J30 - but it only was from mid December to February (temps 33 - 63 deg.F) - and I had control of "Base Timing " adj. if necessary , infact I have a "Summer" and a "Winter" scratch mark for quick setting.The hotter the Ambient temp. you better be using the highest Octane you can get ,especially spirited driving or racing action!!! There is a form of detonation you cannot hear that hammers bearings , rings ,pistons ,valve seats etc. which is brutally multiplied by high ambient (ie. Summer) HEAT, coupled with ,if done over thousands of miles in ignorance - a motor becomes a "DOG". Glen 11/29/2017

[EdBwoy]

That's interesting. I wouldn't expect much difference with the seasons, considering how hot the inside of an engine gets. Even the external surfaces of the engine stay relatively just as hot in the winter as in the summer... for a fully warmed up and operating engine, of course.

But the mini-explosions makes sense. Constant pinging can't be good for anything, haha.


As dstreamer says above, I suppose all you lose with the VQ35 is the smoothness and the luxury feel.
Is that fuel with10% ethanol in both situations or just for the regular gas?
Also, I assume the MPGs you posted are for the M35, right? I rarely if ever approached 20 in the QX4.

[macgiver]

The outside "Hot " air enters the engine (which to a degree is stabilized by the coolant/radiator /thermostat system) BUT - this Ambient "Hot air" IS the X factor causing the so-called critically lowered detonation curve . Thus people install "Cold Air Intake Systems" , superchargers need/good ones HAVE "Intercoolers" for the boosted ambient compressed intake air ( extremely hot!!). The motor is a conglomeration of so many "Factors" - not limited of course to the previously mentioned few , but on topic - yes the engine does stay within engineering "specs" ,(better&better these days) but as we see that's just tip of the iceburg for" the gas into the tank" - to " the rubber meets the road " of power output & efficiency . Glen 11/30/2017

[gavnator]

I have never used anything but Tier 1 93 octane in my M35X. I bought it off lease in March of 2009 with 31,000 on the clock. Today just turned 86,000. Car runs as smooth as the day I bought it. Why mess with success!!