[Sammy]

I found a 96 bronco with really low miles and everything checks out on the car but im worried cause he was using high onctane gas and a freind of mine told me its bad on the pistons or somthing... is this true? is there anyway way to see if the higher octane did anything to the engine or is it just a waste of money and the engine is fine... Thanks

 

[miesk5]

Yo Sammy,
It was just a waste of $ to use the highter O gas. When i had to use the Higher O, (because regular gas wasn't available at that moment in time) the CEL would light off till the next fill-up was added. The Ford service dept. said this seemed to happen w/the 96's OBD II (EEC V) for some strange unexplainable reason. BTW, the CEL didn't light off due to a loose gas cap whch is a know factor in modern vehicles.

Now, piston damage could occur (and he used hgh O gas to alleviate this) because the timing was advanced due to an aftermarket computer chip install...most chips end up in advancing the timing to where detonation (pinging ) occurs when using reg O gas, resulting in the higher O requirement. For instance, from the Jet chip folks; "Can I run regular gasoline? No. All tuning is designed and calibrated for 91 or higher-octane fuel. In some cases 89 octane may be used"

http://www.jetchip.com/faq.htm

 

[Domin4nt]

I just know that it says in the manual for my 96 that it is supposed to only drink 87.:shrug

 

[Davids78Bronco]

The reason alot of guys use the premium and supreme in their engines, is to cover an engine knock noise. Which could most likely mean it's got an excessive amount of engine deposits and carbon bulidup. If this is one you're looking at buying, I'd either pass on it, or offer half the asking price and start looking for a rebuild, or donor engine

 

[Sammy]

Thanks alot there isnt any strange engine noise or anything so hopefully everything else will check out... thanks again

 

[gobucs]

Hey, another close person, take it vehicle to a shop, or lift the valve covers. The valve covers tell tons about the engine, and abuse.

 

[Crazed]

I always thought you needed higher octane with higher compression...??

 

[84brownbronco]

i run premium in mine. it runs rougher with regular. and my dad bought it new and he said 89 octane ran rough in it when it was new. so he used premium. so i do to.

 

[Crazed]

I have always used plus in mine, the big tires made the engine work pretty good with the 5.0....I have been figuring I will need premium when I get the 357 fired up because of the high compression

 

[Davids78Bronco]

if your engine was made for 87 octane, or whatever the low number is, then run it on 87.

the higher the burn rate is the higher the gas rate is to detonttion.
if you dont have detonation leave it. the higher ocatane fuel acually burns slower rather than faster....

 

[84brownbronco]

yeah with 87 or regular it detonates. it back fires and all that good stuff. with premium it runs like a champ.

 

[knarf121]

in all my cars ive always run a tank of premium through every once and a while because i heard it cleans your engine out a little,

i filled the bronco up with premium for the first time yesterday, the engine runs a lot smoother and quieter, but i LOST POWER! i swear! i dont understand how higher octane would reduce my power band, i lost a good portion of my lower end..

i have a k&n intake and after market muffler, nothing fancy and she goes like a bastard with 87 octane so i think ill stick with that.