"DO NOT USE 93 OCTANE" ?

[HoosierDaddy]

I believe using 93 causes too much stress on the 2.7 and is causing valves to drop and destroy the motor.

Sponsored

 

[HoosierDaddy]

I asked my dealer to fill my truck up with premium before I picked it up. They said NO! They were to cheap. Said they fill all the vehicles with 87. I use premium. My 7.3 f-350 deisel dually gets better mileage.

Running joke over at ClassicBroncos.com whenever somebody asks about getting better mileage .... tow it behind a diesel truck.

It's no joke either!
I had a 2001 F250 PSD and it did get better mileage towing the Bronco on a trailer than the Bronco did under its own power! LOL

 

[mpeugeot]

From what I've read, both the 2.7 and 2.3 have a 10:1 compress in ratio, which is a little high for 87 octane. You might experiment with 91 to see if your mileage or smoothness change. Your computer may very well be combating some "unnoticeable" predetonation.

MY 2.7 Tacoma has a 9.6ish compression ratio and runs noticablely better on 91.

That being said, if you live in an area where premium fuels aren't sold very much, your local peteol tank farm may very well be sending premium fuels to lower octane gas station tanks, just to cycle it out of their system.

Are you kidding, on a direct injection motor 10:1 compression is NOTHING. I might add that I ran 10 PSI of boost on an 11:1 miata motor using California winter piss-water 91 octane (which is worse than 87 octane in most other states), and that was a port injected 1.8 liter that made over 300 HP at the wheel!

 

[mpeugeot]

I believe using 93 causes too much stress on the 2.7 and is causing valves to drop and destroy the motor.

Explain the thermodynamics behind that logic. That's f'ing hilarious. Increasing octane doesn't increase stress, period.

 

[myrealname123]

I'm Ricky Bobby, if you don't use 87, then f*** you!

#octanewars

 

[JohnnyBronco]

No. At the time the ARCO Clear was their premium gasoline. Sorry but I don’t remember the octane rating. Their jet fuel, JP4 and Jet A, was kerosine/diesel “grade”. IIRC, flash point and “gel” point were important. I remember sampling a huge tank of JP4 one night with a US Navy inspector observing…. They were very particular about what they bought.

In the 60s Atlantic , as ARCO, was known sold a "clear" gas when all other gasolines had a slightly brown or bronze tint. I don't recall if it was the first unleaded or just refined different but it was what you wanted for outboard motors to mix with oil (2 cycle)

 

[JohnnyBronco]

Running joke over at ClassicBroncos.com whenever somebody asks about getting better mileage .... tow it behind a diesel truck.

It's no joke either!
I had a 2001 F250 PSD and it did get better mileage towing the Bronco on a trailer than the Bronco did under its own power! LOL

A little bump draft and keep turning left

 

[JohnnyBronco]

Are you kidding, on a direct injection motor 10:1 compression is NOTHING. I might add that I ran 10 PSI of boost on an 11:1 miata motor using California winter piss-water 91 octane (which is worse than 87 octane in most other states), and that was a port injected 1.8 liter that made over 300 HP at the wheel!

The Mazda Sky-active spark controlled compression ignition engines run at 14:1

 

[George Ellis]

3.75%, but point taken

Mr. Spock! You are alive!

 

[HoosierDaddy]

Explain the thermodynamics behind that logic. That's f'ing hilarious. Increasing octane doesn't increase stress, period.

It was supposed to be hilarious.... I forgot the "sarcasm" font. Lol.

 

[BigMeatsBronco]

Explain the thermodynamics behind that logic. That's f'ing hilarious. Increasing octane doesn't increase stress, period.

Yeah if anything, it would be the other way around...knocking from poor fuel and too much timing can cause valve damage

 

[Drex]

It was supposed to be hilarious.... I forgot the "sarcasm" font. Lol.

Everyone else got it, no worries.

As an aside, sarcasm ceases to be sarcasm if you call it out when writing/saying it. So... there's that.

 

[MrWindowsAZ]

You also have to be wary when travelling into Mexico. IIRC, the predominant grade down there is 85 octane.

 

[hozer]

Since y'all seem rich as hell I'll chime in and say at $7/gallon here for 93, all I've ever used is 87 and had zero issues, getting 19mpg in the city @ 3,400ft of elevation.

Unless towing something I see no need nor benefit to running a higher octane. Unless you drive the shit outta your Bronco or have infinite free money (like many here seem to) save it lol.

Turbo is not big enough and revs don't go high enough where I'd think you see any noticeable difference under normal conditions. If you like to drive fast, sure more octane and the computer will do its thing, but I think for the average Joe its a waste in a Bronco

 

[UtahLars]

...were the first words out of my salesman's mouth...after I took delivery of my 2DR/WT/SAS (2.7L) last week.
Can anyone tell me why?
Struck me as V E R Y odd.

Thanks!

It is inconceivable that using high octane gasoline could actually be harmful to the engine. So this may have been economic advice (it is probably the case that using 93 over 91 won't be all that noticeable on this vehicle given how its tuned out of the factory), or he might be a misguided treehugger.

Folks get excited about using lower octane than what the mfr recommends, but this too is unlikely to cause serious damage. Anti-knock sensors are universal and with normal driving they will prevent serious damage from premature fuel detonation. Of course, if you do hear knocking with low octane fuel, don't use it. On the other hand, if you are using low octane fuel where higher is recommended to save money, you may not actually be saving much. That's because if you lean on the anti-knock sensor to avoid knocking when using low-octane fuel, you probably won't get optimum fuel economy. So it might be a wash and you might as well use at least the recommended minimum.

Sponsored