Whats the deal with the 91+octane BS its a focus

[CrawlnSVT]

Ive put 78,000 miles on this car and I'm thinkn yesterday WTF premuim!!!! With the gas prices these days I said screw it I FILLED up with 89 the other 78,000 miles with 93.....

80 plus miles NO problems, next tank is 87 I'm tried of the gas prices

If it blows whatever still have the 100,000 powertrain on it:cool2:

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[rdsnake]

at:at:at:

 

[Rotzs99]

its been shown that regular octane will not harm engines that require premium, it just reduces the power. I've read it on a few other sites.

 

[ANIMAL]

I thought you can only run lower octane on cars equiped with nock sensors......in which the computer can then compensate for it? Does SVT Focus have this?

You can run lower octane in cold weather though......I do this every winter and then up the octane as the temps go up. All without changing timing, but my Mustang runs VERY cool and doesn't really reach full temp during the winter.

I run 87 during 30's and lower.
I Run 89 up to around 60 deg. and switch to 93 after that.
100 at the track or during real nasty summer heats.

 

[DaSnoBordr]

its the same with the contour. i don't really feel like trying anything lower then premium. it ran funny when i had a 1/4 tank of 89 i tried when i bought the car. so i've stuck with premium since

 

[CrawlnSVT]

its the same with the contour. i don't really feel like trying anything lower then premium. it ran funny when i had a 1/4 tank of 89 i tried when i bought the car. so i've stuck with premium since

Man I tell you what Its feels like the car is running better AND I'm getting better gas mileage for sure:clap: Dont ask me how?!?!?!?!

 

[DaSnoBordr]

i think alot of my driveability problems have to do with my reman alternator. common problem with my car. although its been much better since when i cleaned out the intake manifold.

 

[Wiked03]

Ive put 78,000 miles on this car and I'm thinkn yesterday WTF premuim!!!! With the gas prices these days I said screw it I FILLED up with 89 the other 78,000 miles with 93.....

80 plus miles NO problems, next tank is 87 I'm tried of the gas prices

If it blows whatever still have the 100,000 powertrain on it:cool2:

If you car is tuned for 91 octane and you use 87, you run the risk of detonation under heavy loads.

If you really do the math on how much using 87 will "save" you, you will go back to using premium.

 

[CrawlnSVT]

never had the car tuned unless ford does it, but I dont see the point, whats really different engine wise then the base focus.....Car runs great with 89 and I got on it with no problems


Saving money wise every penny matters gas prices are NUTS!!!

 

[rdsnake]

The dealers no there shit, they wouldn't use higher octane gas if they didn't need it...I highly doubt you no more then the engineers that built the car, I don't even for that matter.

Your only asking for problems down the road.

 

[Wiked03]

never had the car tuned unless ford does it, but I dont see the point, whats really different engine wise then the base focus.....Car runs great with 89 and I got on it with no problems


Saving money wise every penny matters gas prices are NUTS!!!

Yes it comes from Ford with a factory tune. The SVTs are likely tuned a bit more aggressively that your standard focus, hence the extra performance and need for a little more octane. You may get away with the lower octane for a long time, but performance will suffer and the risk of engine damage is increased.

Lets assume you dive 15k miles/year. If you average 24mpg (guessing), then you will burn 625 gallons of gas. 87 octane is typically about $.20 cheaper than 91 or 93, so your yearly savings is a whooping $125. Doesn't seem worth the risk to me.

 

[CrawlnSVT]

yeh i guess your right..... I still think its gay

 

[jaykruger]

Every time gas starts spiking I have to go over this with some one, especially like the toyota, and acura guys who have premium recomended, it is "safe" to run with the lower octane, though these things can happen in a very few cases. (note I am not talking about high compression engines here 11:1 or better)

Your car will lose power, not as much as you can really tell in most 1-3% but it does go down. Unless you have a low compression car. Some cars will trigger the CEL when run on low grade fuel, I know the acuras would really dislike the low grade 87 (i.e. walmart or whatever) and trigger the emissions for bad/uncontrolled burn. Most all cars have a knock sensor and retard timming and spark to compensate (hence power loss)


Bassically the octane rating is the gas's ability to not predetonate and the higher your compression ratio the better fuel you need. I get people who will argue with me all the time but the fact is for your average street car there is no diffrence in 87 and 93 fuel. the reason that car will knock on low grade fuel most of the time is because of another problem, most likly carbon build up which MAKES THE COMPRESSION RATIO HIGHER!

All gasoline has the same "cleaning additives" in it.

So unless your running a 10.5:1 ratio or higher on a NA car you can use whatever gas you want. As for the boosted folks stick with the good stuff.

 

[Ear Rak]

yea, my mustang actually says to use 87 in the manual...its great.

 

[SecondMustangGT]

You can use lower octane unless you and going to be getting on it. The higher octane actually quenches the spark some what to kept it from detonation. Higher octane actually hurts performance if it is not needed. The spark knock is actually caused by too much heat and the engine almost dieseling. The high octane kinda puts out the extra flame. I get a kick out of the locals that put Aviation gas in there stock cars if they are going to race some one.

 

[FuelSlut]

The dealers no there shit, they wouldn't use higher octane gas if they didn't need it...I highly doubt you no more then the engineers that built the car, I don't even for that matter.

Your only asking for problems down the road.

+1 you may encounter some problems. Its all basically in the mapping of the stock tune, if you really dont want that agressive of a tune and dont mind some performance loss, buy a predator tuner take it into a dyno shop and have the car tuned for 87 octane, and keep the stock tune for when you want the performance. If its tuned for 92+ use it its done that way for a reason.

Like I said if it bothers you that much to spend the extra .25 cents retune your car for lower grade fuel. But the predator isnt cheap and neither is dyno time so you do the math, the extra 25 to 35 cents for premium wont add up for over 2 years than what would cost you to do this retune. Just throwing that out there. Good Luck.

 

[macdiesel]

Dunno, under my gas gauge it states "Premium fuel only" so that's is what I'm sticking with. Maybe if it said "Premium fuel recomended" I might be willing to try a lower octane. Wiked03 summed it up best.

 

[Redman]

svt focus = 12 gallon fuel tank. 93 octane = .20 more per gallon than 87 = $2.40 more per fill up. I wouldn't beat on an svt focus with 87 octane in it. You can slowly damage the pistons / head. I would Just spend the extra 2.40 a tank of premium. Even if you fill up 2 times a week it's only $20.00 a month. Not worth the risk.

 

[InfraRedSVTF]

So unless your running a 10.5:1 ratio or higher on a NA car you can use whatever gas you want. As for the boosted folks stick with the good stuff.

The SVT Focus spec sheet says 10.5:1 compresion There is too big of a risk to run 87.