Contour Enthusiasts Group Archives Forums General General SVT and premium fuel.

me=jealous

What would happen if you put 104 octane gas in the tank?

The stock SVT calibration is set up for typical "premium" fuels (91-94 octane) under all conditions. There are some conditions where 89 will work as well, but there is a "safety net" so to speak, in the knock snesor, the knock sensor will catch detonation, and retard timing to eliminate it. This gives a sort of an "emergency" capability of the engine to use lower grades of fuel or guard for the infamous "bad tank of gas".

That said, run only the fuel your engine is designed for if you can help it. For the SVT this means 91-94 (any of the typical premium fuels, sorry for oyu poor guys out west )

and on the 104 stuff, don't waste your time or money, increasing octane is only intended to keep pre-ignition (detonation) at bay, and if you are not having detonation issues, higher octane will not help you. not to mention some of the higher octane "race" fuels are leaded, which is bad news for your O2 sensors and cats.

Well I guess I'll jump in here with both feet. Again. I've posted about this before.

I use 87 octane in my 98 SVT E0.

With 136,000 miles on it it has had only about a dozen tanks of 91+ octane in it. I can find no difference in MPG or performance. And I often (if not nearly always) drive in a very spirited manner.

Have I ever heard any detonation? Yes, three times. All three times on hot winter days (we have some of those in Southern California). So that would have been with winter blend fuel. It was also only present at light to moderate throttle acceleration. It was very mild, what may be called a "trace ping". It went away with hard acceleration (richer fuel mixture) and at constant load and speed.

With that said, I also meticulously maintain the engine including the fuel system. The air filter is changed every 15,000 miles. The throttle body is cleaned often, at least every 10,000 miles. The oil is changed every 3,000 miles. Injector cleaner is added to the fuel with every throttle body cleaning. All this to minimize the carbon build up in the cylinders and ports and to keep the injectors free flowing. If I felt for a moment that I was harming the engine I would use higher octane fuel. Others may not be able to keep such a close eye and ear on their engine.

Octane is nothing more than a measure of the fuels ability to resist ping. It does not in and of itself create more power. Other things that inhanse power may make the slower burning higher octane fuel necessary. If you don't need the extra octane you are just paying extra for something you don't need.

So I'm not saying that this is for all SVT owners, but it works for me.

Just my $0.02
the mileage also depends very much on where you pump gas - my favourite gas station here is on a hillside, and if I fill it up so that the nose of the car is significantly lower than the rear, I can fill in at least a gallon more (at the same needle position).

This may influence the mpg calculations well.

Tiv

I agree. We have 94 oc. here in Ohio. Sunoco is my place of worship. I can feel a difference!

You should get 30 mpg on the highway anyways. The gauge says to use premium fuel only. But I won't knock the man who has 136k miles on 89.

100 octane gas is sold near my house in syracuse, ny...however it is illegal to pump it into your car.. so you have to bring a gas can and fill that first, then put it into your car. I dont know why, but ill ask my friends.

You may not feel any problems from low octane fuel & infact the owners manual says its ok to use on occasion (by accident) BUT you are probably hurting power. C&D did an article about 1 year ago with several cars using 91 & 87 octane in a dyno comparison. The car designed to run on 87 octane gained a slight amount of power on 91 (maybe 1-3, not enough to be worth the cost). But 91 octane rated cars lost more on 87, 5-6 HP or more. I can get 91 for 10 cents more per gallon (Amoco on Tuesday). A 5 HP gain would cost alot of money after cheap mods like filter & y-pipe. not "cost effective" to run 78 if power is a consideration. SVT Duratec is a special motor & deserves to be treated as such.

Gasoline is probably the cheapest thing you will every buy for your car.

Assuming 15K miles/year at 25MPG, you will buy 600 gallons of fuel/year. If the cost difference between 87 and 93 is $0.20/gal, then you will "save" only $120 or about $10/month

For those of you who live in an area where the difference is only $0.10/gal, then you will save a whopping $5/month or $60/year.

Most of you don't have the time/resources Big Jim has to work on his car. (Like a Ford shop that he runs, not a knock on Big Jim, just the facts.) So your best bet is to run the fuel that Ford/SVT recommends.

TB
Who knows gasoline is the cheapest fluid to purchase at the Quicky Mart, in any grade