Thats really interesting...in Oz we have what we call cheap grade fuel at 92 Octane, premium unleaded at 95 octane and ultimate at 98 octane. I can notice the difference in performance from 95 to 98, so I can only imagine the effects of 89...All that said, we pay about 40% more for fuel to start with........ Hi performance Subaru WRX Sti's etc, simply won't run on less that 98!!
89 octane gas????
- Thread starter xi guy
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This topic has been discussed ad naseum at bimmerfest.org. I also am frustrated with gas prices ... and didn't plan on a 25 cents/gallon PERMANENT increase around Labor Day '03 (one expects prices to go up around Labor Day and then come down) when I bought my '04 325XI last year. I also don't mind giving up an extra 3-5% per year to the oil companies to cover the cost of living. But 5% of $1.60 is 8 cents ... not 25-30 cents. That's gouging.
That being said, the owner's manual says no less than 91 octane. It says nothing about the consequences of not using at least 91, and my dealer also advised me not to use less than 91. So 93 it's been ever since I bought the car. I don't like it, but I don't want to risk using less. Frankly, if you figure out what the difference in $$ works out to per year (I think for me I figured about $2 per fillup and about $150-200/year), it's just not worth taking the chance.
That being said, the owner's manual says no less than 91 octane. It says nothing about the consequences of not using at least 91, and my dealer also advised me not to use less than 91. So 93 it's been ever since I bought the car. I don't like it, but I don't want to risk using less. Frankly, if you figure out what the difference in $$ works out to per year (I think for me I figured about $2 per fillup and about $150-200/year), it's just not worth taking the chance.
Steve Neu, someone told me about higher octane being cleaner and I guess I believed it without questioning it, also that same person said that it burns cleaner and better. Do you know how the higher octane gas offers better resistance to knocking? Thanks.
jes330, actually, in Australia, the numbers you get are called, Research Octane Number and here in the US it's Octane Rating. Octane Rating 91 is the same as Research Octane Number of 96. So I guess 98 is somewhere between 91 and 92 or 93 or something close to that.
BTW My dad knows this guy who is crazy on economy and once he tried putting 10 bucks worth of 89 in the tank and driving until the bulb came on and puttint 10 bucks worth of 93 in and driving until the light came on and he said that it turned out to be the same amount of miles or a little more for the 93. He may be lying but this guy is so cheap you can't believe it.
jes330, actually, in Australia, the numbers you get are called, Research Octane Number and here in the US it's Octane Rating. Octane Rating 91 is the same as Research Octane Number of 96. So I guess 98 is somewhere between 91 and 92 or 93 or something close to that.
BTW My dad knows this guy who is crazy on economy and once he tried putting 10 bucks worth of 89 in the tank and driving until the bulb came on and puttint 10 bucks worth of 93 in and driving until the light came on and he said that it turned out to be the same amount of miles or a little more for the 93. He may be lying but this guy is so cheap you can't believe it.
I copied this from the API web site :
What is octane and why is it important?
Octane measures a fuel's resistance to engine knock. The right level of octane prevents engine knock and ensures optimum performance. The most common levels of octane are 87 (regular), 89 (mid-grade) and 93 (premium).
What is engine knock?
Engine knock is uncontrolled combustion associated with using gasoline with too little octane. The knocking or pinging sound may be more noticeable when accelerating or climbing hills.
What if I use gasoline that doesn't have enough octane?
If you hear knocking, it could, over time, damage pistons and other engine parts. If your car has a knock sensor, it will compensate by slowing spark timing. Your engine will be protected, but possibly at a slight and sometimes noticeable loss in power and acceleration. Roughly half of today's vehicles are equipped with knock sensors.
What if I use premium but don't really need it?
Most cars give optimum performance on regular or mid-grade gasoline. If you're buying premium and your car's not running any better than it does with a lower-octane gasoline, you're probably wasting money. However, some cars may operate better on premium because of additives. Additives, which are found in all gasolines, keep engines clean and make them run more efficiently. Some brands have more effective additives and some use bigger doses in their premium grades.
Steve
What is octane and why is it important?
Octane measures a fuel's resistance to engine knock. The right level of octane prevents engine knock and ensures optimum performance. The most common levels of octane are 87 (regular), 89 (mid-grade) and 93 (premium).
What is engine knock?
Engine knock is uncontrolled combustion associated with using gasoline with too little octane. The knocking or pinging sound may be more noticeable when accelerating or climbing hills.
What if I use gasoline that doesn't have enough octane?
If you hear knocking, it could, over time, damage pistons and other engine parts. If your car has a knock sensor, it will compensate by slowing spark timing. Your engine will be protected, but possibly at a slight and sometimes noticeable loss in power and acceleration. Roughly half of today's vehicles are equipped with knock sensors.
What if I use premium but don't really need it?
Most cars give optimum performance on regular or mid-grade gasoline. If you're buying premium and your car's not running any better than it does with a lower-octane gasoline, you're probably wasting money. However, some cars may operate better on premium because of additives. Additives, which are found in all gasolines, keep engines clean and make them run more efficiently. Some brands have more effective additives and some use bigger doses in their premium grades.
Steve
Oh for the love of god... not this topic again! Does nobody remember this thread from two months ago?! How quickly we forget... use 89....
Previous octane-related bashing... http://www.hotbimmer.net/forum/showthread.php?s=&threadid=4586
Previous octane-related bashing... http://www.hotbimmer.net/forum/showthread.php?s=&threadid=4586
Gas is getting pretty damn expensive, though...paid 2.17 for 91 today! (Chevron)
I'm in San Diego...more specifically La Jolla...![[bigcry]](/images/smilies/icon_smile_bigcry.gif "Big Cry [bigcry]")
But for g-dsakes, if you can afford the car, then just put the best gas...my buddy is a chemist at Chevron and he tells me that its all pretty legit...91 is 91 and techron is some proprietary tertiary amine...in other words the structure is not available, probably because the patent is still pending...because if i had it, i would make it myself in lab!! damn!
I'm in San Diego...more specifically La Jolla...
But for g-dsakes, if you can afford the car, then just put the best gas...my buddy is a chemist at Chevron and he tells me that its all pretty legit...91 is 91 and techron is some proprietary tertiary amine...in other words the structure is not available, probably because the patent is still pending...because if i had it, i would make it myself in lab!! damn!
FYI, 95% of the premium gas in FL is 93. At least that what the labels on the pumps say. The other 5% are 91 octane, those are the cheaper gas stations like RaceTrac.
There are 3 grades at our gas stations (the 95% group): 87, 89 and 93.
Current prices are 1.59, 1.69, 1.79 at the high end and 1.55, 1.65, 1.75 at the low end.
There are 3 grades at our gas stations (the 95% group): 87, 89 and 93.
Current prices are 1.59, 1.69, 1.79 at the high end and 1.55, 1.65, 1.75 at the low end.
Well, my manual says the recommended fueuls is "Premium witha minimum octane rating of 91 AKI." It goes on to say "BMW engines are equipped with knock sensors and will adapt automatically to different octane ratings, provided that the minimum octane requirment 87 (AKI is met." Later, "Fuels with higher octane ratings will provide enhanced performance and lower fuel consumption, while the use of fuels with lower octane will leave the opposite effect."
I recall a tech article in Roundel. The mechanic said he would stick to 91. He said the savings in lower octane would roughly equal the drop in miles per gallon. Interesting.
However, he said on long road trips, where the engine isn't taxed, but simply driving for hours, straight, and high speed and optimal engine temps....there is no reason not to put the middle grade in the tank. In that case, he said the savings made sense. But, again he said to time it so you return to 91 when you're back in city traffic.
I stick to Chevron like a lot of guys posts on here....and I've notice a difference, believe it or not. They say there is no difference between the difference brands because oftentimes they are supplied by the same regional refineries. The ONLY difference, however, is the additives. And Chevron's Techron is recommended by BMW, for whatever reason. Anybody know why?
I recall a tech article in Roundel. The mechanic said he would stick to 91. He said the savings in lower octane would roughly equal the drop in miles per gallon. Interesting.
However, he said on long road trips, where the engine isn't taxed, but simply driving for hours, straight, and high speed and optimal engine temps....there is no reason not to put the middle grade in the tank. In that case, he said the savings made sense. But, again he said to time it so you return to 91 when you're back in city traffic.
I stick to Chevron like a lot of guys posts on here....and I've notice a difference, believe it or not. They say there is no difference between the difference brands because oftentimes they are supplied by the same regional refineries. The ONLY difference, however, is the additives. And Chevron's Techron is recommended by BMW, for whatever reason. Anybody know why?