Fuel Octane

[CreedAllen]

Does the SVTF require high octane fuel(91)? I read that the compression ratios cause it to require higher test.

Thanks.

[SVT3658]

Yes, 91+ octane is required. It says it on the gauge cluster and on the inside of the fuel door

[skicat]

I've been using 87 in my 02 SVT since last summer. No knocking or other probs. Computer may be adjusting timing so I lose some output, but I'm not street racing, so I don't care. A buddy has been running 87 in his wife's SVT Contour for years with no ill effects.

[SVT3658]

Good luck with that....

Seriously, it's 20 cents per gallon on a 12 gallon tank.....you're not even saving 3 dollars per tank. I hope you're putting that 2 bucks and change in a piggy bank somewhere for when your engine lets go....

If it calls for it, I'm always gonna use it. You spent the extra money to get the high performance version, so why be a cheap bastard on the gas you put in it?

[RPMcCourt77]

I just wish I had the opportunity to put 91+ in my SVT. Up here in Alaska, the highest octane available is 90. I'm running a FocusSport tune and adjusted the global spark to hopefully accommodate for the lower octane (this was the only recommendation I've been able to find).

[bmylez]

Originally Posted by skicat

I've been using 87 in my 02 SVT since last summer. No knocking or other probs. Computer may be adjusting timing so I lose some output, but I'm not street racing, so I don't care. A buddy has been running 87 in his wife's SVT Contour for years with no ill effects.

Yeah umm...that makes no sense. Go buy a regular Focus if you're gonna do that. The engine doesn't like it, trust me.

[skicat]

So... is everyone on this forum so rude? Or just the know-it-all punks? I live in SE MI, work for a Ford vendor and have regular contact with Ford powertrain engineers who have informed me what I should and should not do with my vehicle. 91-OCT is recommended but not required unless you hammer the car all the time (which the boy racers on this forum must do). Bought my 02 Focus from a Ford engineer when it had 19k miles on it and have driven it all the way up to 98k today with regular maintenance + 2 issues out of the ordinary: failed clutch master cylinder, failed shift cable. I get lots of compliments on how "new" the car looks, how well it runs, drives, etc. And I work in a bldg full of car guys and gals. U know nothing about my vehicle, nor can you predict when it's going to "let go." I'll post again when it's up to 150K...

[shlbygt]

Originally Posted by skicat

So... is everyone on this forum so rude? Or just the know-it-all punks? I live in SE MI, work for a Ford vendor and have regular contact with Ford powertrain engineers who have informed me what I should and should not do with my vehicle. 91-OCT is recommended but not required unless you hammer the car all the time (which the boy racers on this forum must do). Bought my 02 Focus from a Ford engineer when it had 19k miles on it and have driven it all the way up to 98k today with regular maintenance + 2 issues out of the ordinary: failed clutch master cylinder, failed shift cable. I get lots of compliments on how "new" the car looks, how well it runs, drives, etc. And I work in a bldg full of car guys and gals. U know nothing about my vehicle, nor can you predict when it's going to "let go." I'll post again when it's up to 150K...

From the SVT Supplement:
Octane recommendations
Your vehicle is designed to use
“Premium” unleaded gasoline with
an (R+M)/2 octane rating of 91 or
higher. The use of gasoline with
lower octane ratings may damage
the engine. Gasoline labeled as “Premium” in high altitude areas that are
sold with octane ratings of less than 91 are not recommended.
If your engine knocks under any driving conditions while you are using
fuel with the recommended octane rating, see your dealer

[SVT3658]

Originally Posted by skicat

So... is everyone on this forum so rude? Or just the know-it-all punks? I live in SE MI, work for a Ford vendor and have regular contact with Ford powertrain engineers who have informed me what I should and should not do with my vehicle. 91-OCT is recommended but not required unless you hammer the car all the time (which the boy racers on this forum must do). Bought my 02 Focus from a Ford engineer when it had 19k miles on it and have driven it all the way up to 98k today with regular maintenance + 2 issues out of the ordinary: failed clutch master cylinder, failed shift cable. I get lots of compliments on how "new" the car looks, how well it runs, drives, etc. And I work in a bldg full of car guys and gals. U know nothing about my vehicle, nor can you predict when it's going to "let go." I'll post again when it's up to 150K...

Good for you. I'm not willing to take the risk and go against what is printed in the SVT supplement, on the gauge cluster, and on the inside of the fuel door. It wouldn't be there if it didn't need to be....but what do I know? I'm just a "boy racer"

If being able to read and make intelligent decisions to follow instructions makes me a know it all punk....then I guess I am

And I'm at 160k BTW....

[bmylez]

Yeah but you got to 160k by using premium gas, that's cheating!!!

[CreedAllen]

Thanks for the input by all.
I spoke to a Ford Dealer today and they Master Technician there said that 91 will be better for the engine, give higher performance, but it could live it's life on 87 just as happy.

I am looking in to this before purchasing the vehicle, by the way. I wouldn't buy a car without knowing what fuel it took!

I think I'll run 87 all week, 91 on the weekends(:

[Grommish]

Originally Posted by CreedAllen

Thanks for the input by all.
I spoke to a Ford Dealer today and they Master Technician there said that 91 will be better for the engine, give higher performance, but it could live it's life on 87 just as happy.

I am looking in to this before purchasing the vehicle, by the way. I wouldn't buy a car without knowing what fuel it took!

I think I'll run 87 all week, 91 on the weekends(:

PM me your info.. I'll file it for when your engine decides to go boom.. DIBS on the interior!

Seriously.. .20 cents per gallon difference in price.. Just put 1 gallon less of the 93 in over the 87 if you "can't afford it".

Saying you can't afford 93 over 87 in a tank the size the SVTF has it like saying your too poor for decent toilet paper..

[racer1735]

If you live at any sort of 'elevation', 90 octane burns the same as 91. An earlier post from Alaska mentioned 90 being as high an octane as was available. Same here in the Texas Panhandle. Likewise, 'regular' is 86, rather than 87. It burns the same.

[SVTADAM]

Wow...I am amazed at how a simple question can spark such a bitch fest.

The car calls for 91 octane or better. Period. Thank you shlbygt for posting that info from the manual.

Can the car run on lower octanes? Yes, but it is not advised. If you want to run lower octane fuel, so be it. Each car will respond differently to lower octane fuel. Some may run like a champ, and for a long time. Most likely the engine has inaudible detonation/pinging especially if the ECU cannot pull enough timing to make it run safely.

[CT SVT]

full tank of 93 is $39 right now for me. 87 is $37 so i'll save $2. its better off to get 93 just for the safety for the engine. and me bring a jaguar tech i know how bad it can be if someone runs 87 for so long. cost them $4K to repair the problem. and thats a used engine. lol plus 15hrs labor at $122 per hour goodtimes. no warrenty if you use wrong fuel.

[bmylez]

Originally Posted by racer1735

If you live at any sort of 'elevation', 90 octane burns the same as 91. An earlier post from Alaska mentioned 90 being as high an octane as was available. Same here in the Texas Panhandle. Likewise, 'regular' is 86, rather than 87. It burns the same.

I think you misread the SVT supplement a bit.

To re-quote what the supplement said:

"Gasoline labeled as “Premium” in high altitude areas that are
sold with octane ratings of less than 91 are not recommended."

That is the opposite of what you just said.

[zetec-j]

Originally Posted by SVT3658

Good luck with that....

Seriously, it's 20 cents per gallon on a 12 gallon tank.....you're not even saving 3 dollars per tank. I hope you're putting that 2 bucks and change in a piggy bank somewhere for when your engine lets go....

If it calls for it, I'm always gonna use it. You spent the extra money to get the high performance version, so why be a cheap bastard on the gas you put in it?

+1
totally agree. i never understood people who paid extra for a nicer vehicle but were too cheap to put the right fuel in it. I see people all the time with audis putting 87 in. i guess they have to save that $2 to put towards their starbucks.

[bullitt042001]

I'd say use what is recomonded,not what you think is right,I'm thinking there is a reason why ford put very clear on the fuel gauge "premium fuel only" .
But the car is yours,you do whatever you want with it,me personally ,I love my foci and I want the best for it.

[fritotec]

I live in SE michigan also and I would not think to put anything less than 93 octane in my focus or my 2004 cobra or my 97 WS6, Thats because they all call for 91 or better. I would pay to have them towed then put 87 octane in any one of them.

[svtf02red]

Originally Posted by CreedAllen

Thanks for the input by all.
I spoke to a Ford Dealer today and they Master Technician there said that 91 will be better for the engine, give higher performance, but it could live it's life on 87 just as happy.

I am looking in to this before purchasing the vehicle, by the way. I wouldn't buy a car without knowing what fuel it took!

I think I'll run 87 all week, 91 on the weekends(:

I don't mean to offend, but these guys by no means are the end-all in automotive knowledge.

Higher compression generally returns higher combustion chamber heat. In higher-heat situations, you risk pre-detonation (where the heat from the compression itself or other heated particle in the combustion chamber causes the ignition of the fuel/air mixture before the spark plug ignites).

High-octane fuel burns more efficiently at a higher temperature, and likewise, lower-octane fuel burns more efficiently at a lower temperature. You want a very rapid burn in the combustion chamber instead of an explosion. Consider sticking to the 91 as pre-detonation insurance for your SVT. When the boys at Cosworth design an engine and recommend 91+ octane, I listen

Just because the engine management system in the SVT is good enough to handle running 87 octane doesn't mean you should. If you live in a warmer climate, I definitely would not run anything less than 91 unless you are in an emergency situation and you cannot find 91 for some reason.

Remember - the boys at Cosworth know way more than the Ford Dealer "Master Technician" will ever know

[blackbird]

Sure, you'll probably have no issues running mid-grade if you don't hammer on the car and aren't wringing it out. On most cars if you wanted to be sure you could always connect a scan tool and watch what ignition timing and knock retard are doing.

With that said, lets do the math on the difference between regular and premium. Assuming you drive 15k miles a year that comes out to 1250 miles a month. The price difference in most parts of the country runs around $.20/gallon more for premium. Assuming you average around 25 mpg per tank you'd be using 50 gallons of gasoline per month. That makes the grand total in savings of using regular vice premium grade gas $10 per month or a little over a couple bucks a week.

While the car may tolerate it, especially with conservative driving and during the colder winter temps (where there's less chance for detonation/knock), the savings isn't worth it to me.

[SaucyMuffin]

I don't understand why someone would buy a sports car and then starve it....

[smitty]

Originally Posted by SaucyMuffin

I don't understand why someone would buy a sports car and then starve it....

You're not really starving it. If anything, it's the opposite as 87 octane ignites more readily than 91 octane. That is the problem. With lower ocatane, pre-ignition (pinging) happens more easily because octane actually inhibits ignition. That way, you can run more timing which helps torque. The ecu will pull timing to protect the engine if it senses knock, so you're not getting all the power available from the engine with 87 octane. He seems ok with that part.

Whether forcing the ecu to do this all the time by running 87 octane is good for the car or not is, I gather from this post, a source of some debate. The car is not engineered to run 87 octane, so it isn't running at it's optimum efficiency, and like anything else, octane ratings are within certain ranges. So maybe he's running 86 on one tank and thinking it's 87? Regardless, the modest savings netted by running lower octane gas doesn't make sense to me either, and it's possible that he's not seeing the best fuel mileage by running it this way, so the savings at the pump is being lost on the road. As well as forcing the car to run outside it's normal operating parameters.

[1svt4u2c]

So.......I dont wish to be a daddy any time soon, but I enjoy making love to my girlfriend. However, I do not wish to purchase condoms, because I "cannot afford" them.


Hmm, what do you think would happen in that situation?

Basically what I'm saying is, it says put 91in it for a reason.