min octain requirement for 997??
08-17-2010, 05:41 PM
#16
Drifting
all the above are correct.
however if ever you have the chance to find premium unleaded >96 octane make sure you take the opportunity just to experience what the engine is really capable of. here in europe we are lucky to have what is called racing gasoline which is nominally 100 octane (our normal gasoline is 95 and there is also a power version of 98). You guys wouldnt believe what a difference it makes...its like adding 50hp to the car
however if ever you have the chance to find premium unleaded >96 octane make sure you take the opportunity just to experience what the engine is really capable of. here in europe we are lucky to have what is called racing gasoline which is nominally 100 octane (our normal gasoline is 95 and there is also a power version of 98). You guys wouldnt believe what a difference it makes...its like adding 50hp to the car
But then we are not paying $6.73 per gallon.
08-17-2010, 07:55 PM
#17
Rennlist Member
Yeah, I had a cousin visit last month from Germany and he found it very odd that our 'super/premium' gasoline octane rating was on par with the lowest grade of normally available gas in Germany. I think 92 or so was the lowest they offer there, while in Puget sound we get 87, 89, and 92 as the premium. (and yes, I know the computations 'could' be different methods, but I think they use the same averaging as we do)
08-17-2010, 08:03 PM
#18
Rennlist Member
however if ever you have the chance to find premium unleaded >96 octane make sure you take the opportunity just to experience what the engine is really capable of. here in europe we are lucky to have what is called racing gasoline which is nominally 100 octane (our normal gasoline is 95 and there is also a power version of 98). You guys wouldnt believe what a difference it makes...its like adding 50hp to the car
I'll trust my datalogger over anyone's "butt dyno" any day. These cars are tuned for 93 (US) octane and it serves no purpose to exceed that.
08-17-2010, 08:40 PM
#19
Race Director
This is just a myth. The pumps at MSR Houston ran out of 93 octane (equivalent to European 98 octane) over the weekend so I had to fill up with 98 octane (US measurement, not Euro) for my last two sessions on Sunday. It doesn't make a bit of difference. My lap times were unchanged by the unnecessarily higher octane, even with the weight reduction from my dramatically lighter wallet.
I'll trust my datalogger over anyone's "butt dyno" any day. These cars are tuned for 93 (US) octane and it serves no purpose to exceed that.
I'll trust my datalogger over anyone's "butt dyno" any day. These cars are tuned for 93 (US) octane and it serves no purpose to exceed that.
08-17-2010, 08:47 PM
#20
Nordschleife Master
Yeah, I had a cousin visit last month from Germany and he found it very odd that our 'super/premium' gasoline octane rating was on par with the lowest grade of normally available gas in Germany. I think 92 or so was the lowest they offer there, while in Puget sound we get 87, 89, and 92 as the premium. (and yes, I know the computations 'could' be different methods, but I think they use the same averaging as we do)
But then we are not paying $6.73 per gallon.
But then we are not paying $6.73 per gallon.
Europe's RON 98 is equivalent to US (available most anywhere except the West Coast) AKI 93.
West Coast 91 is barely distinguishable from 93 (or EU 98). Blending above AKI 93 adds no advantage whatsoever.
08-17-2010, 09:14 PM
#21
Track Day
Join Date: Jul 2010
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Higher Octane ratings mean that the fuel can be compressed more without spontaneoulsy igniting without a spark (knock). Engine manufacturers specifiy an ideal Octane rating for the tuning/compression of the engine. Higher performance engines have higher compressions.
Exceeding that Octane will provide no benefit as there is no additional energy in higher octane fuel. Burning gas with a lower than recommended octane will cause the engine to adjust itself (timing) to run safely in a less than ideal manner. This will usually mean slightly less power and fuel efficiency. Some higher octane gas also includes fancier detergents/additives but most "premium" fuel (91/92/93) from the same station will have the same additives. Short answer - no real harm but some loss of power running slightly lower than recommended octane gas - no real benefit in running higher than recommended octane gas.
BTW, most gas stations only have two tanks and achieve the various octane ratings by blending them in the pump. Gas stations are regulated more to ensure that you are getting the volume of gas you are paying for rather than the actual octane you are paying for. So if you find that the same octane rated gas from station "A" seems to burn better than from station "B", it is likely because you are getting the correct octane from station A and an incorrect Octane from station B.
Exceeding that Octane will provide no benefit as there is no additional energy in higher octane fuel. Burning gas with a lower than recommended octane will cause the engine to adjust itself (timing) to run safely in a less than ideal manner. This will usually mean slightly less power and fuel efficiency. Some higher octane gas also includes fancier detergents/additives but most "premium" fuel (91/92/93) from the same station will have the same additives. Short answer - no real harm but some loss of power running slightly lower than recommended octane gas - no real benefit in running higher than recommended octane gas.
BTW, most gas stations only have two tanks and achieve the various octane ratings by blending them in the pump. Gas stations are regulated more to ensure that you are getting the volume of gas you are paying for rather than the actual octane you are paying for. So if you find that the same octane rated gas from station "A" seems to burn better than from station "B", it is likely because you are getting the correct octane from station A and an incorrect Octane from station B.
