I don't know how good it is to run a mixture of toulene regularly tho. Might facilitate corrosion of injector and fuel pump seals.

Seriously, anyone who bought the car and REALLY doesn't want to run 91+ AKI should spring for a "detune" using Osiris.

I'm sure you could have it tuned to run (with a lot less power) on regular or mid grade. As you can have more than one tune stored on the ECU, you could just toggle back and forth between the low octane DD tune and the higher octane performance tune.

Lot of money up front, but if you did it that way it would be safe and I guess eventually you'd make the money back.

Or... just buy premium and don't floor it so much. That will work too.

If people don't want to buy 91-93 octane, then you could always ride a bicycle.:bowrofl:

I have heard some dealership do not put premium in the cars that do require it. I know when I bought my G35 several yrs ago the sales guy said you do not need to put premium even though it says it. You will be fine with regular..... I was like WTF.

I took my mom's '11 Acura MDX to the Acura dealership yesterday for service. I started to talk to the guy that sold my parents the MDX & what fuel to use. He was like yeah it does say premium, but regular will work w/o any problems. He said he had a TL that he put 60k miles on it with regular & now has an MDX that has 20k miles with only putting regular gas. He has not have any issues or knocking noise from using regular instead of premium fuel.

I know my mom has had 2 TL's & is own her 3 MDX & only uses regular gas. She has never complained about any knocking noise from the use of regular gas. All Acura's require premium fuel as do BMW, Infiniti, Nissan, Lexus & etc. Oh my gf brother in-law has an Infiniti QX 56 that has 100-125k miles & he only uses regular gas. He has not had any problems of any sort from using regular gas.

I am not a mechanic and I have not done a study, or survey to find out how long would it take before a car that uses premium that is actually getting regular gas will last. I believe it really depends on how you drive the vehicle. If your vehicle has a supercharger or turbo charger, then you better put premium (maybe octane boosters if needed). If you are looking to take your vehicle to the track on the weekends, then you should put premium gas in your vehicle. If you are one of these people that like to go balls to the wall on the freeway, then you should use premium gas. If you are the type of person that only goes b/w 70-80 on freeways, then you could possibly get by with using regular gas (not sure how long).

In the end it is safer to just go with what is recommend (premium) for our vehicles, but it is also up to you as an individual.

You don't have to be a mechanic -- just read up on octane. Octane numbers indicate how likely it is to autoignite -- higher numbers are harder to ignite than lower numbers. Heat (from the air fuel mixture itself, or from lingering flame kernels from spark events) and cylinder pressure (either from piston characteristics or boost) can both cause fuel to auto ignite -- we only want the fuel to ignite when a timed spark event (i.e., when a spark plug fires) happens, not before and not after.

More ignition advance means less time for heat to dissipate from the piston head; higher CR's and or boost mean greater cylinder pressures. Therefore, octane requirements will depend on the CR of pistons, boost (if any) and ignition timing (other factors, such as atmospheric elevation, overall engine temps, etc. matter quite a bit too, but these are the key issues to keep in mind).

If the fuel ignites before or after the timed spark event, the pistons move out of time, creating stress on the engine internals, particularly the piston and rods. That phenomenon causes the "knock" sound you hear and it can result in cracked pistons or ruined rod bearings. Really bad autoignition events can create intense flame kernels that literally melt the piston head -- it will look like someone took an arc welder to it.

Anyway, the moral of the story is, you should use an octane no lower than recommended for the motor based on how it has been built and tuned. The requirements were determined empirically on an engine dyno when the motor was built and tested, and if you add forced induction, you pretty much have to once again determine octane requirements by observing power output and evidence of knock to determine new octane requirements to run safely.

Just saying "Ah, it'll be fine" is really taking an unnecessary risk.

It's worth reading up on so you know what you are doing and why it matters, and if you like cars, it's interesting stuff :tup:

Dealers are cheap and pinch every cent. Most dealers fill the vehicle with regular on new car fill ups and will even have the lot techs who fill it up watch the fill up till the gauge points to the F indicator and save a gallon or so....I would recommend a octane booster at purchase of a new car at least.

+1..... Oh I completely agree with you. When I went to test drive the Nismo for the first time we had to stop & get some gas b/c it just got off of the truck a couple days ago. Well the sales guy only put 3-4 gallons of regular gas in it & was going to try to get reimbursed for it.

The higher the octane the slower it burns & the lower the octane the faster it burns.

Uh, a bottle of octane booster isn't going to do much, which is the whole point.

You're better off demanding to accompany them on the journey to the gas pump if you are that worried.

Or tell them not to bother filling it up -- you'll do that.

Failing that, if you are that concerned, drive around at fairly low revs, putting very little load on the engine (less load means less torque produced, means less likely to autoignite -- although it is certainly possible to knock even at idle), get through a 1/4 or 1/2 tank of gas and then top off with high test.

Or break out the siphon hose and start sucking :bowrofl:

The message I'm getting from people on here is that they don't trust car dealers as far as they can throw them (fair enough) but they DO trust snake oil salesmen selling unregulated, mystery fuel additives (why?).

I was just ranting about the dealers filling up with regular so others would know and figured since you questioned the dealers method was a good post to quote....but if I ever do buy a new car I might demand premium if not a gas card lol

As far as the difference a booster makes I am not questioning other than if I know regular was used I hope it helps, recently got my Z shipped and the shipping company put over 100 unexplained miles on the car and I filled it up and added a booster... good news is car drives great

+1....... I will agree that the SOB will put regular gas in the tanks instead of premium. What is this "snake oil salesmen selling unregulated, mystery fuel additives?" I have never heard this before & could someone please elaborate on this for me.

I'm being facetious -- I mean that the octane boosters are not regulated in any way shape or form, so use at own risk.

That said, I wouldn't count on them to do anything especially good OR bad (other than drain your wallet a bit).

Seriously, if anyone here buys their new Z and thinks the dealer topped it off with regular, the best thing you can do is drive around gently (i.e., no flooring it, no redlining it -- not a great idea if breaking in a new engine anyway...), burn through 1/4 to 1/2 a tank, and then top off with high octane.

Hell, if you can find it, some Sunocos have 100 AKI at the pump. Half a tank of that plus regular will get you where you need to be (although I believe fuel blending winds up being not quite that simple in terms of effective octane...).

That's a much better way to go than adding a couple bottle of octane booster, crossing your fingers, and driving however you would normally.

Oh, and lookie what I found... http://www.fueltechexperts.com/2008/...which-is-best/

Remarkably, a few of them added a point or two of RON (although, keep in mind that AKI is the average of RON+MON... actually, a good rule of thumb on RON to AKI conversions is RON*.95=~AKI value -- example, our car requires 96 RON or 91 AKI, 96*.95 = 91.2), most added less than a point.

Still not going to be very helpful on a tank of 87. Siphon or gently use up, top off with high test. Done.

Find a gas station that sells 100 octane race fuel. They are actually quite common. I tried octane booster and had no results. If you mix half race fuel and half 91 octane you get 95.5 octane. That seems to be the sweet spot for my 370z. I tried pure 100 octane but it didn't run as good as 95.5. There are many octane calculators online. You can mix 91 and 100 to achieve whatever octane you want.

:inoutroflpuke:

Holy necro-bump, Jamesb1.

Welcome to the forums?

Wowzers.. wat was the q again?..lol