try unplugging your battery for a while before you put in the 94.

wait, you guys have 94 in canada? sweet.

 

Yup we got 94, the thing with octane i think is that the higher the octane the harder it is to combust, therefore reducing the chance of knocking/pinging... but now with the colder weather and all, i think it's extremely hard for the fuel to combust! i don't know if my theory is true or not, but please correct me if i'm wrong in anyway... also would adding colder spark plugs affect this as well?

 

Does anyone know if you can mix different octanes together? I was thinking of mixing 114 octane fuel with 91 octane fuel for dragracing and stuff like that. would it work?

 

you can mix octanes.

 

the fuel you get from gas stations is sometimes (or most of the time) mixed octanes with the octane rating averaged together.

 

Stick with whatever Ford recommends. Your engine was designed with that octane in minde for optimal operation. Spending more on a higher octane is a waste of money - it does you nothing. Paying less by goign with a lower octane will make the engine crap out of you. Unless you change your compression ratio you should be sticking with Ford's recommendations.

 

still no one has answered my question, will the 94 octane make the car run more like crap in colder weather?

 

According to Ford, the engine is rated for 91+, meaning any reasonable level above that should be fine. I haven't even seen 91 around gas stations in Michigan in a while. Most all stations around here have 87, 89, and 93, and I don't really notice any problems at all with the 93 in cold weather.

Maybe just resetting by unplugging the battery might work, otherwise it could be a number of things, and while I doubt it has a whole lot to do with the fuel, you could be right. In any case, just use 91 in the winter if it works better, it isn't worth the hassle to pay more for gas that gives you trouble, and there may not be a reasonable explination for it.

 

i run 93 all the time, ive never had a problem, even when its cold.

 

still no one has answered my question, will the 94 octane make the car run more like crap in colder weather?

No. And in fact you can use a lower octane rating in winter. Less money - same performance. If 91 gas runs OK in your engine in summer, then mid-grade "89" gasoline in your Canadian winters is perfectly acceptable.

I run 89 all year with no knock, no problems and *no computer codes*. I would only use 91+ under difficult conditions - steep hills, WOT, towing loads, etc.

 

No. And in fact you can use a lower octane rating in winter. Less money - same performance. If 91 gas runs OK in your engine in summer, then mid-grade "89" gasoline in your Canadian winters is perfectly acceptable.

I run 89 all year with no knock, no problems and *no computer codes*. I would only use 91+ under difficult conditions - steep hills, WOT, towing loads, etc.

really? must be a pain in the ass having to pull over, flush out your fuel system, and then put in high octane every time you have to drive up a hill.

good thing you dont live in san francisco.

 

really? must be a pain in the ass having to pull over, flush out your fuel system, and then put in high octane every time you have to drive up a hill.good thing you dont live in san francisco.

I've lived in San Fran. You'd have to be a fool to own a car in the City. Besides, it's cold enough in SFO in summer to run mid-grade up Telegraph Hill...

I should add that there is a 1-2 octane point requirement difference among engines of the same design - due to normal manufacturing tolerances. When Ford makes its recommendation, it has to be very conservative. My SVT engine runs perfectly well on 89 gasoline - probably I could push it even under difficult conditions and it will still run optimally well on mid-grade gasoline - and I save money with essentially no risk. Other SVTF engines may require 91 at all times - even winter. You just never know unless you do some practical testing on the engine in your specific SVT...

 

94 octance may have trouble combusting in really cold weather, but once the engine is warm it shouldn't be an issue. When you pull out after 5 minutes where are you oil temp and water temp gauges at? Are they still low? Does the surging/studdering go away after 10-15 minutes?

In Michigan we have 93, and 94 isn't that big of a bump. You could be having other issues. It wouldn't hurt to take it into the dealership, but pick a good day. ie, it happens on cold days, so don't take it in on a warm day.

silversvt, I wouldn't mix 114 with anything and put it in your car unless you've switched to an ORP. The lead in the 114 will ruin your cat.

 

Hey silversvt, is there another type of race gas where your at? Because i know we have 100 and 110 and the 110 you have to put into a container before you put it into your car (probably because of safety precautions). Also, you can mix them but you will want to run your regular octane down to between 1/4 of a tank and E and put at least 5 gallons in. And i know when i would put 100 octane in my car it would run a lot quicker but i would fill up two times before going to the track or street racing with kids so the gas can mix well and you get the most out of your money. I'd reccommend around 100 octane because if you don't have any Fi in your car it won't be that big of a difference if any.

 

i drive 93 octane all the time in cold weather - never had a problem

 

You should run the lowest octane you can run without detonation (ping). The higher the octance the slower the burn (relatively). Yes, you can run slightly lower octane in the winter.

 

Bad news for those who live in California - the state understands colder conditions = more oxygen and they modify the MTBEs (or it equivalent now) during winter, so I suggest not running a lower octane.

I really dislike the fact that we have to run 91 when many equivalent cars do not, but I suggest you do or the longevity of your engine is going to suffer.

 

All that we have here for high octane is 114 octane besides the pump 91 octane. (I live in ND) not much choices here. I do have an orp so i'm not worried about the heat in the exhaust. Will it make a difference if i mix 114 and 91 octane for drag racing? I am assuming that you would have to reset the engine computer when you did this also.

 

btw, does anyone know if you can change your name on here, I don't have a silver svt anymore..

 

To me it sounds like when you filled up with the 94 you got a tank of bad gas. It may have clogged up your fuel system, thus the difficulty with 91. I would say if it doesnt go away, take it to the dealer. They can flush the lines and replace the filter, etc.

 

Stick with whatever Ford recommends. Your engine was designed with that octane in minde for optimal operation. Spending more on a higher octane is a waste of money - it does you nothing. Paying less by goign with a lower octane will make the engine crap out of you. Unless you change your compression ratio you should be sticking with Ford's recommendations.

You are just wrong. Have you ever tried it yourself professor??? Or are you regurgitating something you heard or read.

100 octane mixed with 91 makes a NOTICABLE difference in my SVT. NO DOUBT ABOUT IT.

I quit taking drugs a few years ago, so don't use that against me.[thumb]

 

You are just wrong. Have you ever tried it yourself professor??? Or are you regurgitating something you heard or read.

100 octane mixed with 91 makes a NOTICABLE difference in my SVT. NO DOUBT ABOUT IT.

I quit taking drugs a few years ago, so don't use that against me.[thumb]

You are right, I've talked with some guys from SVT and the SVT tech at my dealership and they say that the SVTF engine has a high enough compression to get something out of higher octane fuels, above what is reccomended, but unless you are pushing it to the limit every time it makes very little difference. However, at the track it is great to have a higher octane in there.

 

Drukenmountie, I like your sig[thumb] [thumb] [thumb]

Every morning I get in my ride it's a chance to have fun. The freeways of SoCal are my track...I know them all like the back of my racing glove.

The opponents are out there, I just have to find them...most of the time nothing exciting happens, but it only takes a sec for something to develop.

getting harder to find peeps I haven't schooled.[]

 

Yeah, the gains of running higher octane fuel is more noticeable in the higher RPM's when it burns the most fuel, you'll feel more of a kick and boost when up in the 4K's and above, i usually went to about 6K to 6500 when getting top performance outta the race gas on the interstate at late night.

 

...some guys from SVT and the SVT tech at my dealership...say that the SVTF engine has a high enough compression to get something out of higher octane fuels, above what is reccomended, but unless you are pushing it to the limit every time it makes very little difference. However, at the track it is great to have a higher octane in there.

The SVT's compression ratio 10.2:1 is moderate. Nothing like the monster American engines of the 60s or today's free-spinning high compression Euro engines. So why would higher octane benefit an SVT engine at all ? The one and only benefit of higher octane is to allow higher compression. All other talk of "more power" in high-octane gas is bogus.

I suppose it's possible that the SVT engine is somehow restricted on 91/93 gasoline. Maybe Ford maps retarded ignition spark even on "ordinary" premium 91/93 gasoline. But why would Ford do this and leave unused power "on the table" ?

I'm very skeptical of claims that racing gasoline makes any difference at all in an ordinary unmodified SVT engine with stock compression. If someone messes with spark timing while they use racing gasoline then I suppose there's some room for argument.

There's some manufacturing variation among engines. My SVT engine - for example - does just fine on mid-grade 89. It would make no difference AT ALL in my engine to use full premium 91/93 gas. (I haven't pushed it WOT, with a trailer, in Arizona summer, going up a mountain). Someone else's SVT engine might have slightly higher compression, and might need full 91/93 premium to generate its full power, and that engine's full power might be a couple of horsepower higher than mine. The manufacturer's recommendations have to be conservative to accommodate all manufacturing variations, so Ford publishes a premium gasoline requirement... If individual SVT owners did their own testing, I'd bet half of them would find they can get their engine's maximum power on mid-grade 89, safely and with little or no knock.