I have a 1985 full size Bronco with the 351W High Output engine, AT. Which fuel octane should I use - 87? 89? 92? I just got the Bronco and the previous owner doesn't know which is correct. I need to fill it up, but I can wait for an answer if someone out there knows. HELP! Thanks!

 

Man it rilly wont make a huge diffrence witch you use. 92oct to treat her right$$$. 87oct for your wallet!

 

If it doesn't ping with 87 then 87 is what I would run.

 

I used to blend gas for Mobil oil a few years ago, You'll be fine with 87, 92 is for a hotter burning eng. like a sports car. Thats why race cars burn 103 . I would use the 87 for everyday use and run 92 When you go off road IMHO(when you are working the motor harder)

 

Check Out tech tips on Superchargersonline.com for more info!!!

 

I guess I should have been more specific, so I'll try again with my question. Does anyone know which octane gasoline Ford recommends for a 1985 Bronco 351W HO, factory 4 bbl, AT? No guesses or assumptions please, I'd like to know which is correct. Thanks.

 

Did You even Go to That websight?
IT'S 87!!

 

Thanks for the info, and I did go to the website. However, all I wanted to know was what octane Ford says to use in this vehicle, not the scientific definition of octane. I hoped someone who still has a 1985 Bronco owner's manual could tell me what's in that manual. Going to the website provided some interesting information on octane definitions, but not the information that I wanted - the octane requirements for a 1985 Ford Bronco with a 351W HO, 4 bbl, AT. The website info on octane definitions was akin to receiving instructions on how to build a watch when all I wanted to know was the time of day. But again, thanks for the info.

 

According to http://www.fueleconomy.gov/feg/findacar.htm

Ford Bronco 4WD
8 cyl, 5.8 L, Auto(3), Regular

Assuming that is a stock motor in a 85 Bronco

 

Steell - thanks, that's what I was looking for! And, thanks for the website. Merry Christmas and Happy Holidays!

 

i like to run my cars and truck on 87 most of the time then run 92 or 93 every three or four tanks to help clean it out

 

I've got the 85 Bronco w/351 HO engine also. They won't run right with 87 octane. Will give a minor ping and the fuel mileage goes downhill fast. Mine runs fine with 89, with a little super thrown in every once in a while.