SVT Octane Requirements?

[LenMinNJ]

The SVT manual and the label inside the fuel door says that my '04 SVT needs 91 or more octane.

Higher octane eliminates knock in higher compression engines when accellerating.

I've fueled it with 89 octane and it doesn't knock at all, not even a little bit. Not even under hard accelleration.

Does the Zetec have a knock sensor? Does it retard the timing if it detects knock?

If not, is there any reason why I can't run 89 octane fuel?

Thanks!


Len M. (in NJ)

[Sponsor]

[IcEMage]

Well the car was made to use 91 or higher so anything less might cause problems. Plus the higher compression rate of the svt motor likes the 91 or 93...I ran 89 in mine once and it ran like poop...well not that bad but I could deff tell a difference in the power and smoothness.

[svt2nv04]

yes there is a knock sensor. you can run whatever you want, but i wouldn't run anything lower than 91. you're only saving pennies man

[PNYEXPS]

My fuel economy suffered enough that it actually saves me money to run the 91+.

[LenMinNJ]

The knock sensor explains it -- thanks!

Yes, on 89 octane the performance is lower. Good to know though that it'll run on 89 without other ill effects.


Len M. (in NJ)

[jrpasmo]

^^^ For now.....give it time.... ;_)

[SVTbronco02]

i dont think there's any ill effects to running 89, i've owned this car since new and have never noticed a difference between the two, 89 and 91 that is

[JRODSVT]

Does it truly matter to save at the most 2 bucks a tank a gas? I mean come on it is worth the piece of mind.

what is 2 bucks going to nab you. I guess after a month you could buy yourself dinner for one night, or get 2 packs of Cigarettes, maybe you can get case of dirt cheap beer (this shouldn't even be called beer).

I'd rather not risk damage to my engine just to save 2 bucks a tank.

But what ever man it is your money so do what you will.


edit: Yes it has a knock sensor but it has to detect knocking first to retard the ignition I'd rather it not knock at all.

[LenMinNJ]

As long as it has a knock sensor (as reported above), running at 89 won't cause any ill effects.

I've been running it on 89 all Summer and the only ill effect I've noted is that it has noticeably less accelleration in 1st and 2nd gears.

Now I'm back to 91 and appreciate the extra oomph!

[svt2nv04]

i wouldn't run on 89 regularly man