Does higher Octane (89, 93, or 94) give better MPG?

[Haxaw]

I have the 5.0L V8 and I was wondering what everyone burns for gas. I know that the regular unleaded is the cheapest and everyone tells me thats what I should burn. I know that my Mustang has the same engine, well somewhat, and it eats regular like its water. Would different plugs make a difference? I have Bosch +4 in my other two vehicles and I love them, its just that $50 is a lot for just plugs. Anyone tried any fuelsystem cleaners or octane boosts that work well. I may put in a can of RESTORE Oil Additive for V8s, that stuff does work great, no gimicks especially for higher milage vehicles.

 

[01EB5.0]

i think the $50 Bosch plugs are worth it. I mean they last 4 times as long as other plugs so you don't have to worry asbout them for over 100K. i am very happy with my plus 4 plugs.
in terms of gas milage due to octane, i always have run 87, but I tried 93 a few times to find no increase in gas milage..I actually saw a very sligh decrease. Maybe it was the weather or something, but My truck runs fine on 87 and that is what the truck is made to run.
In terms of the fuel system cleaner, I usually run a bottle every 2nd or 3rd oil change. I never notice a difference, but maybe in the long run it'll keep everythig good.
Now in terms of the oil I would not advise running additive. Most quality oils already have additives that your engine needs. If you use synthetic they already have detergants and stuff in them to reduce sludge and keep your engine running good.

 

[Alec]

Higher octane gas won't help your engine unless it needs it. If you notice any pinging or undue sluggishness with 87, try 89. Many members run 89 over 87 in their stock trucks. Sometimes the engines just run better with 89. However, unless you have many mods, you probably don't need 93. I know that until I got my chip, 93 did me no good over 89.

 

[Stephen]

No, running on high test (93) will actually shoot your economy all to hell. I run 89 in the winter and 87 in the summer.

 

[config]

I just finished my second tank running regular (87 octane) and I did not expereince any pinging or ill effects. I do have the Superchip installed and have been running Super unleaded ever since but I decided to experiment with regular and my mileage stayed the same - 15.5MPG combination of highway and city.

 

[RU MAN]

I know in mine which is 4.0 and when i use 93 or 89 it does run better, stronger, but 87 does get better Mpg and it is cheaper. But that is a 4.0 V6 and 5.0 V8 atleast needs 89 to run like it should. I would think and this is a guess but with a 5.0 you would get the best Mpg with 89, worse with 87, ok with 93. 93 will make your engine run better then the other 2, but if your just driving to work or what ever then 89 would be the best for your needs. If you give your truck hell, and drag it go with 93.(your gas gauge is goin to drop fast anyway). But this is what i think, and you can do what ever you want. Just try all three out and see which one you like. lata

[Edited by RU MAN on 02-12-2001 at 02:33 PM]

 

[JWood]

87 Pings in my 93 - except with Chevron

Usually there is a noticable ping with the 87 octane, especially Shell, not sure why. However, the best 87 I have found is Chevron ...barely a noticable ping; is it the Techron...?

 

[regassert]

A pretty decent web page about gasoline octane. Don't worry, its a quick read. Dead Link Removed

 

[rockylaurence]

No gain with 93

I run 93 because mine pings on anything else. Gas milage stinks regardles of what grade I use.

 

[Flounder]

I had an odd experience this past fill-up with 94 from Sunoco. Usually I get 220-250 MPG on 89. Using 94 I have gone 255 and still have a quarter tank... I'm thinking fluke.

 

[newtek007]

run 87 89

Engines are designed with different compressions ratios which do better on regular octane gas. Usually, truck engines are 9.5 compression ration or somewhere around there. Most engines in the is range run better with regular octane gas. Using higher octane gas will actually foul up the engine with carbone deposits in the long run. If your engine is pinging using regular gas then you are either using really cheap gas or you need a tune up. Yes, the universal distributor that Ford uses does actually go bad. Hope it helps.

 

[01EB5.0]

He's right. the V-6 OHV has a compression of 9, while the SOHC is 9.7 and the V-8 is 9.05. the premium if more geared twards engines with higher compression. if you don't need to run it, then I'd just go with 87.

 

[timfretwell]

Re: run 87 89

Originally posted by newtek007
Engines are designed with different compressions ratios which do better on regular octane gas. Usually, truck engines are 9.5 compression ration or somewhere around there. Most engines in the is range run better with regular octane gas. Using higher octane gas will actually foul up the engine with carbone deposits in the long run. If your engine is pinging using regular gas then you are either using really cheap gas or you need a tune up. Yes, the universal distributor that Ford uses does actually go bad. Hope it helps.

I agree with you completely, this is not a high compression engine so, by design, it should not require a high octane fuel. 87 should be fine according to the owners manual. I use the Mid grade (89 octane) and always a name brand like Shell or Amoco. But my 94 XLT pings! I only have 44K miles on it. I refuse to believe it needs a tune up at such an early stage. (if thats the case than I'll never own another FORD) And I NEVER use cheap gas. So whats the deal with the ping?? I never get a check engine light either. I knew I should have bought the 4Runner!!

 

[yob_yeknom]

Originally posted by newtek007
Using higher octane gas will actually foul up the engine with carbone deposits in the long run.

There is your answer. That is very true.
In case you need convincing, I work at a gas station. A year ago I pumped gas there. (now I'm a cashier) One lady in a JGC always got 93 octane gas. She kept coming in complaining that our gas sucked, but she liked full service so she had to keep coming back. (we are the only full service around, and the only one I even know of anywhere) I told her to use 87 octane but she wouldn't listen. After many trips to the dealer to have her GC de-carbonized (they had been telling her not to use 93 octane) they finally said they would not de-carbonize it anymore since she kept using 93. She uses now 87 and has not had the problem since.

 

[jimbo74]

check your owners manual. it will say what your car needs to operate at its optimum