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11-21-2014, 01:35 AM
Hello!
I am totally new when it comes to Mustangs and V8 and I have a newbie question regarding fuel. In Sweden we have two common gasoline types at the gas stations; 95 octane and 98 octane. What would be the best fuel choice for a 428/460 engine? My guess would be 98 octane but I have seen some people writing about 87 octane which is not available in Sweden. Would 95 octane be the better choice then?
Best regards
Thomas
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In a very simplified answer, the higher the compression of the motor the greater the need for a higher octane. Higher octane will not hurt a motor - it just costs more at the pump. A higher octane will burn cleaner thus increasing your power and possibly mileage.
If the motor seems to "ping" (a pre-ignition knock) and it is timed correctly it is the motor's way of saying it needs a higher octane.
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Steven gave you a very good straight forward answer and is probably as accurate as we can get, since we are not scientist's. #1 we don't know if the grading system in Sweden is compatible with it in America. #2 the temperature and climate can cause differences and needs for different blended fuels, which may or may not be similar to America. My guess is look up your local car club and find someone there that has some knowledge on the fuel in your country. Wish I could help more. If it runs fine on 95 ok if it pings, run the 98. God if they really have 98 octane fuel. I want to move to Sweden! JTS 71 Mach1
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Hi JTS71Mach1 - we have 98 at the pump out here to. Do I make up the spare bed now? BTW great answer from SH. I just had a head rebuild on one of my daily drives. Problem - so much metal was taken off by some PO that the engine now pinks (knocks) so the head will have to come off again so the combustion chambers can be resized.
On a related matter - unleaded in leaded engines and valve recession. I read that the research on that was carried out on motors running full rpm with full load for hours and hours. It turns out that 'our' cars will never suffer with that. Only octane rating will make any difference.
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We have 91,95 & 98 octane over here. The whole four years I have had the car I have run 95 with an additive in it. After moving to the country a little while back the 95 octane is very rarely stocked at the local service stations and sometimes it is the 95 with E10 added which I won't use in the Mustang. Recently out of desperation I had to use 91 octane in the car (it was that or else start pushing
) and I didn't notice any difference in the performance.
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Cool, thank you very much for your input guys!
I suspected the 98 octane was the way to go but wanted to make sure.
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(11-21-2014, 11:16 AM)Mach1FatherFigure Wrote: Hi JTS71Mach1 - we have 98 at the pump out here to. Do I make up the spare bed now? BTW great answer from SH. I just had a head rebuild on one of my daily drives. Problem - so much metal was taken off by some PO that the engine now pinks (knocks) so the head will have to come off again so the combustion chambers can be resized.
On a related matter - unleaded in leaded engines and valve recession. I read that the research on that was carried out on motors running full rpm with full load for hours and hours. It turns out that 'our' cars will never suffer with that. Only octane rating will make any difference.
Count me in as soon as I can afford to have It shipped over there, I'm READY. It should only cost a couple hundred to ship it Down Under. RIGHT???
JTS 71 Mach1
Ps. Thanks for the offer.
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Hi Oztrailer, Sorry you have problems getting 98. IMO go easy on the additives/boosters. Have seen engines damaged with that stuff. I thought that when Mustangs of our era were built 93 was/is top dog and the ignition timing was 'soft' to suit. Maybe someone could confirm /refute this.
I finally found the tuning sticker for her M1 and it states 6* BTDC. The fuel quoted (IIRC) is 91. I was going to time up at 8* as I have 98.
The only petrol additive I have used is RedEx which is getting harder to get hold of.
Smooths out running and lubes carbie parts a treat.
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How your car runs on octane has nothing to do with timing, please do a search for octane and find out what it is, what it does, and how it's used,,,as stated,,high compression, use high octane, you can use high octane in a low compression engine, it won't hurt anything but your wallet,,and it does not run cleaner,,,just don't run low octane in a high compression engine,,,not good,,,
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Hi S10, 'How your car runs on octane'? That is like saying 'How your car runs on 20w-50 has nothing to do with oil'.
Octane rating is a measure of a fuel's ability to resist compression ignition/end gas detonation/pinking/pinging (all terms for the same thing).
Use of the correct fuel has everything to do with spark timing and engine tuning. 'What octane does'? Octane is not an additive it is a measure of the result of blending the fuel.
Using a higher rated fuel will allow a change in spark timing giving either greater economy or a marginal increase in power.
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