Octane fuel

[Mustang351V8]

Does it matter what octane i put in my 92 4.0l Ohv ranger we have 85 E85 87 88 89 and 91 octanes i was told i could put 85 in my truck as long as its zero ethanol? Is this true my ranger has 156k miles automatic.

 

[97RangerXLT]

Do not use E85. it is a flex fuel (85% ethanol) and your truck is not designed to run on it. I am going to guess that you are in a high altitude location if you have regular 85 octane. That will probably work fine if that is the case, but your truck is designed to run on 87 octane. any thing higher runs just the same, only more money goes out of your wallet.

If your truck starts pinging under load, next tank go up an octane level.

AJ

 

[Mustang351V8]

Yea we are at 3400ft elevation. Running a higher octane or lower will it give me more power or kill power? I wanna also find a way to make my straight pipes louder lol

 

[97RangerXLT]

Octane does not indicate the level of power that you can get out of gasoline, it tells you how easy it is to explode or detonate the gasoline (which is what your engine does when it runs)Higher Octane = harder to explode.

The higher altitude means atmospheric pressure is less, which means the air is thinner so a lower octane gas can be used because it needs to be easier to ignite or explode.

Most American made cars and trucks run fine on 87 (or in your case 85) octane gas. Higher performance cars with higher compression engines need higher octane so that the gas explodes when the piston is at the top of the stroke rather than when it is still coming up (this is what causes pinging or knocking, and will degrade the performance and possibly damage your engine).

My2004 Nissan Maxima recommends 91 Octane fuel, because the engine has more compression than the Rangers engine, and while it can run on 87, gas mileage does suffer a bit because the knock sensors in the engine adjust for the lower octane. So while I can run on lower than 91 octane, I get better results and more mileage out of the 91 octane fuel in that instance. And I do come out ahead money per mile wise by paying a little extra for the 91 octane.

The Ranger will not get any performance increase by using higher octane gas. it will run the same, get the same mileage and be just as happy using any grade of gas, so why throw the money away on higher octane when good ole 87 will be just fine.

AJ

 

[Mustang351V8]

Alright thanks ill just stick to 87 its only 3.22/gal i dont wanna risk hurting my motor it already gets enough beating on.

 

[Captain Ledd]

Ha, my younger brother also drives a Maxima that runs a whole lot better and gets better mileage on 91 (it also calls for it).

But unless your engine is built to take advantage of the higher octanes, it makes very little difference. Certainly not enough to justify the extra cost.

 

[Mustang351V8]

Im gonna throw in like 15$ of 85 octane and see if my mother knocks/ticks and go from there.

 

[kimcrwbr1]

I doubt your gonna see much a difference in performance between the 85 and 87. Run the tank close to empty and then run a full tank of each and compare the mileage. My 2012 focus seemed to like the 85 octane I got driving through Montana. I got 37mpg on 85 and averaged 35mpg for the whole trip from WA thru MO to south TX over to CA and back up to WA.

 

[AllanD]

The one case where "Plus grade" (89 octane) or Premium ((91 Octane) is justified in a 4.0 liter ford Engine is if someone "repaired" an engine with the Wrong parts...

Say someone had a 1993 Ranger/Explorer that required having the heads replaced
and 1995 or later cylinder heads were substituted. These later heads have smaller combustion chambers and are intended to be used with the 1995-and later pistons that have larger dished crowns, so their use raises the compression is increased.

My brother's 1992 was set up this way and in most weather conditions required premium (sometimes plus) grade gas to avoid pinging

This set-up would in my personal opinion be the cats ass if I lived where my brother moved to (unfortunately after this truck was burned up in an accidental fire) Casper Wyoming...


at 6000-8000 ft elevation you'd never notice the higher compression causing pinging, it would simply compensate for the lower atmospheric pressure...

I personally have a set of later assembled heads sealed in the factory boxes that I'll use should I ever move to Wyoming

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