Proper octane fuel for 4.9L L6?

those engines were made low compression ,so 89 will work fine.the higher the compression ,the higher the octane needed. dont think youll notice much difference using premium.

On Thu, 20 Oct 2005 21:45:15 -0500, Ford Warrior rearranged some electrons to form:

No need to spend the money. It is designed to run on 87.

You are wasting your money burning plus.

Running high octane fuel will not net you anything but a lighter wallet. High octane does not equal more power. In fact, the higher the octane number, the slower the fuel will burn... Stick with the

87.

So the general concensus would be just to go with the Regular 87 fuel?

Thanks

Not true, 9 to 1 and better compression is no place for 87 octane. It is in owner manual for sales reasons and the only reason some engine have knoc senxors it for 87 octane compatibilty, not for emissions ans every time ECM retards the spark to control knock, it is reducing power and MPG plain and simple. I use plus or better in all my cars and have for years. Even my wife 2000 4cyl Cherokee gains about 2 mpg in city/urban driving with 89 or better gas run better and smoother too. I have a 89

4x4 burb that I have had since new and now has 176K miles on it and it will get 19mpg or better on highway with A/C and 93 in tank and runs great and never pings no matter what. Long ago the best it every did on 87 was about 16 once without A/C and usually 14mpg with A/C on on highway and tended to knock and have a lot less power on hills too. It has not had a tank of 87 for many years now. Personally I think 87 should be taken off the market because it is a through back to the days on 8 to 1 compression in the 70's. Rhet should just have 89 and 93 or so and just two stocks instead of three would reduce the price on 89 too and allow detriot to biuld cars with higher compression for better thermodynamic effieceny and better MPG.