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Octane ratings.....what's the truth?
Saab Saab Automobiles Discussions (alt.autos.saab)
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#11
 
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Re: Octane ratings.....what's the truth? -
04-06-2007
, 08:23 PM
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In his opinion higher octanes are "generally speaking" a scam on automobile users perpetrated by the oil companies and encouraged by the auto manufacturers. |
Mind you most *American* cars are so low-tech that they don't care about octane
rating it seems.
Graham (who once had a car that *required* 100 RON octane petrol)
#12
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| gerry wrote: In his opinion higher octanes are "generally speaking" a scam on automobile users perpetrated by the oil companies and encouraged by the auto manufacturers. Speaks volumes. He's a loonie. Mind you most *American* cars are so low-tech that they don't care about octane rating it seems. Graham (who once had a car that *required* 100 RON octane petrol) |
around the world.
91 RON is aprox. = 87 AKI (the common octane unit of measure in North
America)
100 RON is aprox. = 94 AKI, which is available as premium in many parts of
North America.
103 AKI racing fuel is/was available at a few petrol stations I visited.
#13
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If you had an AERO, I might adjust my answer. That is were Wattenberg's "generally speaking" part kicks in. |
speaking" high-octane fuels ARE a scam? Why?
#14
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On 6/4/07 10:53, in article 461618DA.A45165A (AT) size-nospamhere-fitter (DOT) com, "johannes" <johs (AT) size-nospamhere-fitter (DOT) com> wrote: DervMan wrote: "gerry" <notforgenerause (AT) nospam (DOT) com> wrote in message news:1316l6virkhfj97 (AT) corp (DOT) supernews.com... I know this is old stuff, but I would like some input (hopefully informed) on current thinking, now that gas prices have skyrocketed and there is a real financial significance that just didn't exist "in the olden days". Here in British Columbia, Canada we are paying $1.17/litre in $Cdn or 1.17 x 3.785 (l. / U.S. gal) x .86/1=$3.80 U.S. / U.S. gallon.....and that's for regular. Let's look at about $4.10+ U.S. / U.S. gallon. The book for my car 2001 V70xc recommends a minimum octane (RON) of 91, and I see regulars at 87 and mid-range at 89. Then you should run it on the 91 stuff. Is that considered premium? In the UK we have a different scale, ordinary unleaded is 95 RON, super is 97 upwards. You can buy 102 RON.  I listen to Radio Station KGO (San Francisco) at night and often hear their science Guru Bill Wattenberg (PhD etc. etc. knows all, et al) who says, "If it will run on regular, use regular. A modern sophisticated car engine may not run initially that well, but sensors will "re-tune" to the lower octane and will be fine.....no damage.....no power loss.....no effect on warranty. The theory, as I understand it is that "higher octane" doesn't mean more "power" in the gas, it means elements added to adjust combustion rate. Hmm. Octane is the opposite of cetane in diesel. The higher the octane, the harder it is to get the fuel to burn when compressed - which means you can squeeze it harder for a bigger bang. A higher cetane rating in diesel means it will burn easier when compressed. In his opinion higher octanes are "generally speaking" a scam on automobile users perpetrated by the oil companies and encouraged by the auto manufacturers. Ignore him and try it yourself. Generally, turbocharged cars like higher RON ratings, 'cos the fuel:air mixture can be squeezed harder before it detonates. Pre-detonation is A Very Bad Thing, also called pinking. Saab donks for the last X years, where X is many have had a knock sensor that adjusts the ignition andreduces power to avoid pinking. If you have a turbocharged Saab petrol engine and you run it on a lower RON fuel, it'll produce less power or damage itself. Run it on higher RON stuff and it'll produce the most it can, subject to tolerances / ignition curves. Not put especially scientifically... I normally use Shell Optimax in my 1993 9000CSE 2.0 LPT, 131k miles, but the station on my route was closed for 3 months, then I used Morrisson supermarket fuel (regular only). The engine was OK but not sparkling, there were occasional flat spots which I put down to maintenance, filters etc. Recently changed back to Optimax, and it feels like the engine has been 'cleaned up' as it runs smoother and more consistently. Apart high Octane, quality fuels also contain cleaning agents. Exhaust systems used to be something which lasted for 3 years or so, but I'm really surprised that the exhaust hasn't failed for 6 or 7 years since a box was last time replaced. Wonder if that may have something to do with better fuel quality? |
Quote:
| http://www.thorneymotorsport.co.uk/t..._Results.shtml Check the above link out - is fairly imformative |
higher octane fuel. I didn't see any mention of the handbook of the M3
saying something like "maximum power on 95 RON xxx bhp, maximum power on 97
RON, 360 bhp..."
Because they *do* say that...
--
The DervMan
www.dervman.com
#15
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| gerry wrote: In his opinion higher octanes are "generally speaking" a scam on automobile users perpetrated by the oil companies and encouraged by the auto manufacturers. Speaks volumes. He's a loonie. Mind you most *American* cars are so low-tech that they don't care about octane rating it seems. |
unlike modern stuff they can't adjust themselves on the fly to cope with
different fuels.
Quote:
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Graham (who once had a car that *required* 100 RON octane petrol) |
If's a different scale though.
--
The DervMan
www.dervman.com
#16
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"Walt Kienzle" <wkienzle (AT) core (DOT) com> wrote: If you had an AERO, I might adjust my answer. That is were Wattenberg's "generally speaking" part kicks in. So you're saying if you have an Aero (I do, 9-5, 2002) that "generally speaking" high-octane fuels ARE a scam? Why? |
of higher octane fuel than can the lower pressure turbo engines.
--
-Fred W
#17
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Gary Fritz wrote: "Walt Kienzle" <wkienzle (AT) core (DOT) com> wrote: If you had an AERO, I might adjust my answer. That is were Wattenberg's "generally speaking" part kicks in. So you're saying if you have an Aero (I do, 9-5, 2002) that "generally speaking" high-octane fuels ARE a scam? Why? Other way around. The High Output Turbos in Aeros can make better use of higher octane fuel than can the lower pressure turbo engines. -- -Fred W |
high octane fuel. Minimising fuel cut outs at maximum power. Reducing flat
spots. The cleaning agents in some quality fuels are also worth having.
#18
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"Walt Kienzle" <wkienzle (AT) core (DOT) com> wrote: If you had an AERO, I might adjust my answer. That is were Wattenberg's "generally speaking" part kicks in. So you're saying if you have an Aero (I do, 9-5, 2002) that "generally speaking" high-octane fuels ARE a scam? Why? |
is not needed. AERO's would be one of the exceptions.
I'm glad you didn't say you have a Supercharged Buick Park Avenue. That car
confuses me, I haven't determined if it follows the exception or the rule.
#19
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"Gary Fritz" <fritzxxx (AT) xxxfrii (DOT) com> wrote in message news:Xns990AD9F437633fritzfriicom (AT) 216 (DOT) 168.3.50... So you're saying if you have an Aero (I do, 9-5, 2002) that "generally speaking" high-octane fuels ARE a scam? Why? No, I am saying the opposite because, generally speaking, high octane fuel is not needed. AERO's would be one of the exceptions. |
#20
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In my experience over thousands of miles, the LPT equally benefits from high octane fuel. Minimising fuel cut outs at maximum power. Reducing flat spots. The cleaning agents in some quality fuels are also worth having. |
and/or fuel economy when higher octane fuel is used and the engine is at
normal operating temperature. The OP pointed out that in his location the
price difference among the grades was increasing and was asking what octane
is required so as not to damage his engine. Regular fuel meets that
requirement "generally speaking". He also was concerned about the 91 RON
octane requirement listed in his owners manual (which neglected to inform
him that 91 RON is equal to 87 AKI regular grade fuel sold in North
America).
In North America, the Top Tier initiative (http://www.toptiergas.com/) and
government regulations have nearly eliminated the difference in cleaning
agents among the various grades of fuel for a particular brand.
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