Whats your feel on octane?

My car has 98 in bold green written inside the fuel filler cover. Guess I'm **** out of luck then...

Actually it's 98 sans plomb... But I figure that means wiff no lead...

But as to your question, I've long believed it's all the same no matter what the pump says...

But as to your video, the octane level in fuel has nothing to do with fuel economy or emissions or performance. It has to do with the compression in the cylinder, and if a manufacturer says use this octane, it's because they built the engine to that spec. You get pre-ignition and knock if you use too low an octane. That's why modern cars have a knock sensor to adjust the engine timing to reduce the knock if the wrong octane is used.
 
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I think i read that if you at Coastal altitudes you will see and feel a difference but not at high altitudes.
 
@OP, also, your video talks about "premium" gas, which doesn't mean a higher octane rating per se, it is a different thing meaning extra additives and crap.
 
Rickster said:
I think i read that if you at Coastal altitudes you will see and feel a difference but not at high altitudes.
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Nothing to do with the octane. Well, not really. They sell a higher octane at sea level because of the naturally higher compression in an engine, due to the air pressure. Mainly if you drive from the highveld to the coast, and your car feel like it has more power is due to more oxygen due to the air pressure being in the fuel-air mix in the cylinder during combustion.
 
pinball wizard said:
Nothing to do with the octane. Well, not really. They sell a higher octane at sea level because of the naturally higher compression in an engine, due to the air pressure. Mainly if you drive from the highveld to the coast, and your car feel like it has more power is due to more oxygen due to the air pressure being in the fuel-air mix in the cylinder during combustion.
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I know that but:


Tip from the AA: At the coast, 95 higher octane fuel is best as the air pressure at these lower altitudes gives the best performance and economy. The higher the altitude the lower the air pressure, and the lower the need for a high octane fuel as there is no real performance gain. In this case, 93 low octane fuel is probably a better compromise in terms of cost and economy.

Another factor to consider is the model of your engine. More modern engines may run better on higher octane fuel, especially if they have turbo or superchargers. The difference will be more apparent for older vehicles on long- distance trips, where you’re likely to get more mileage for your money.

Tip from the AA: Unless your engine is turbo or supercharged, you should go for 93.
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Rickster said:
I know that but:
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Pretty much what I said (not just in reply to you). I disagree with:
Tip from the AA: Unless your engine is turbo or supercharged, you should go for 93.
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That is outdated. Pretty much every modern normally aspirated engine works at very high compression and works better on the highest octane you can get.
 
Yeah the only time you would see a difference in performance or fuel economy is if you were driving a car all along on 95 that was tuned for 98 and then suddenly put 98 in it.

Then again modern fuel injection probably compensates somewhat as well.


I recall a very marginal difference in my old Fiesta when running 97 Unleaded when Engen had it.





More so on my Suzuki GSX-R 600 which was more likely to be tuned towards higher octane, but even then it wasn't worth the extra cash.
 
pinball wizard said:
My car has 98 in bold green written inside the fuel filler cover. Guess I'm **** out of luck then...

Actually it's 98 sans plomb... But I figure that means wiff no lead...
.
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What ever happened to higher octane fuels? I'm sure that there used to be 97 octane in PE back in the day.
 
cr@zydude said:
What ever happened to higher octane fuels? I'm sure that there used to be 97 octane in PE back in the day.
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I remember that. I think the hippies got too loud so they canned that octane fuel along with the leaded fuels. I remember they disappeared at the same time. My dad had a hard time letting go, still puts lrp in his unleaded motor bike. Claims he gets more power. Heh.
 
We used to get 98 here in Durbz and before that you could get union which was 100 and was made from sugar cane .
People used to mix union and 98 to give a higher octane .
 
The knock sensors will compensate but at a cost of decreased power and torque.
 
The Skyactiv Mazdas would love higher octane, but we run bare minimum with our 95 RON.
Can anyone confirm if SA Skyactiv's are 13.0 or 14.0 compression?
 
c3n0byt3 said:
The Skyactiv Mazdas would love higher octane, but we run bare minimum with our 95 RON.
Can anyone confirm if SA Skyactiv's are 13.0 or 14.0 compression?
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Octane is the least of the Mazdas problems.

(troll comment)
 
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