what octane fuel do YOU use?

[Mark]

I run 87 octane. Occasionally I'll run 89 because I was sold on the idea that the higher octane will burn bad deposits in the engine. Maybe I'm a sucker...
If you run higher octane regularly...why?

 

[Steve]

Sorry, couldn't vote cause I live in Colorado and regular here is only 85 octane. ;D That's what I run. Anything more than regular in almost every engine is a waste of $$$.

 

[Mark]

GJBroncoMan - you're using regular then. Please vote. that's interesting that in CO regular is 85. I wonder if it varies location to location. I didn't know that...hmm...

Sorry, couldn't vote cause I live in Colorado and regular here is only 85 octane. ;D That's what I run. Anything more than regular in almost every engine is a waste of $$$.

 

[76Broncofromhell]

Mine won't start on anything lower than 91 octane. Damned 10.5:1 compression

 

[Synds9]

when i drive her normal and carefully..retard the timing.. 89.. if im gonna work it at all i have to pump atleast 91

 

[Hnrys69]

87, the motor was built to run on that and when I run higher it runs like crap.

 

[Unregistered]

85 octane...thats very interesting....never knew they actually made it that low. Older engines were meant more for higher octane, but with lower compression...I'd say about 9.5 you could probably run 87. My 351 gets post ignition when I run 87. I can get by on 89 but I run 92-94...whichever is the highest at the pump. I've heard the higher octane will get you more life out of your engine and that it will get slightly better gas mileage which will make up for the few cents more at the pump. It may not be true but I will keep running high test anyway, can't hurt.

 

[ctowery]

100 octane unleaded racing 76 :'( :'( ;D won't run on 91+. But damm it smells good.

Cary

 

[Nuke]

Higher octane does nothing for your engine if it wasn't designed to take it. That means for most of us, the lowest octane in our local is what you should use. At higher elevations, lower octane may be used because the air is thinner.

 

[Steve]

85 octane...thats very interesting....never knew they actually made it that low.

Lots less O2 here at altitude, so less octane is needed. ;D Any station you stop at in CO will have 85 as regular.

As others have said, unless you have high compression (like at least 9.5:1 or higher) more octane than regular is a complete waste of $$$. Over the past few years, some of the news shows like 20/20 have done stories on this, and all have concluded that higher octane is a waste of $$$ for most people. It's kinda like the oil change places convincing you that you must change your oil every 3 mos or 3000 miles. Check the owner's manual for any car made in the last 10 years or more and they recommend regular gasoline and a longer oil change frequency...

BTW, nice cerenkov pic nuke, what do you do for a living?

 

[72bronco]

You're right on that oil change thing. My wife's new minivan only requires an oil change every 7500 miles per manufacturer's recommendation. Given the choice I'll take the advise of General Motors before Jiffy Lube. By the way, I also run 87 octane in my '72 with no problems. Like was said before, all the independent studies have shown that higher octane gas doesn't improve performance or milage. If you run a high compression engine you may need it, but otherwise run the lowest grade you can without pinging. Save your $$ for bronco upgrades!

 

[wildbill]

;D ;D ;D The red one (68) will only run on that 100+ at 4.00 a gal and gets about 5 mpg but damn what a ride 12.5to1. And I found out about that 85 crap the hard way was in wy. they have it to and I didnt look just put reg. in it and it ran bad at the next stop I found the problem and toped it off with 91 and then when mixed it ran much better. Have found Az. Co. Wy. and parts of Nm. use that junk. Bill 8) %)

 

[SeaBiscuit68]

So what was the octane rating available at pumps in 1968? I thought regular and mid came about in the 70s. Wasn't all gas the equivalent of premium back then? My memory is failing me, but I sort of remember that was the case. And if so, then engines made before 197? would want the good stuff? yes/no?

 

[Yellow75]

Not sure if it's because of my timing but if I run regular it pings pretty bad when I get on it. Ethanol makes it run like ass but runs perfectly with 91+ premium. I suppose I could drop the timing down a it but that's no fun!

 

[45acp]

with my timing retarded a hair i can get by on 93. anything less in my motor and it pings like crazy. if you are running a low comp motor, just use 87 unless you're running some hard advance.

 

[Newt]

My personal experience with regular vs premium fuel is that the premium will give better mpg, but not enough to offset the higher price. This of course in an engine that will run well on reg.

 

[Nuke]

BTW, nice cerenkov pic nuke, what do you do for a living?

I'm a reactor engineer for the Harris Nuclear Power Plant. The pict is from the research reactor at NC State, my alma mater.

 

[Unregistered]

I run 10:1 compression and it needs 91+. I also found that anything below that causes it to run a little hotter...with the ping.