MX6_2_RX8

OK, you’re wrong. :D

94 octane burns slower so it can be compressed more before it is ignited with the spark plug. This gives it more power because of the higher compression even though more fuel needs to be used to get the power. It is less efficient for 2 reasons. First, since it is compressed more it is further into the cycle so it has less time to burn completely. Second, it burns slower. So you have a slower burning fuel with less time to burn. The long thin shape of the rotary combustion chamber doesn’t’ help because the burning starts by the plug(s) and the fuel air mixture in the tips is the last to ignite after the “power stroke” is complete. This is the reason that rotarys get crappy mileage even though they are a light small displacement engine which seems like it should do pretty well on gas.

Can anybody back me up on this? I’m pretty sure this is right but I’d welcome comments by the pros.

G8rboy

Correct... the higher the octane, the slower and potentially less efficient the burn, which is why high performance, high compression (NA) or high heat (turbo) engines typically require a higher octane fuel as a detonation preventative. Seems most modern performance cars are coming with knock sensors now, so that if you do run a low octane that is pinging, the motor can sense it and retard ignition timing to prevent damage.

Brice-RX8

That is exactly what I said right?

MX6_2_RX8

Right. I was commenting on the one above you but it took so long to type it your post snuck in ahead of mine.

valpac

iTrader: (2)

Just got back from England last week...

1.10 pounds/liter X 3.79 liters/Gallon X $1/0.534 pounds = $7.81 per Gallon.

(And thats for regular, not premium)

So when I got back the states and saw the prices for regular in my area had risen to $2.18/Gallon, I was shocked. Then I remembered the prices I was paying in the UK....

God Bless America.

Just something to think about as the pump goes Ka-ching.

Tayninh

when folks here pay $7.81 like the UK, you can buy an SUV pretty cheap or they will give them away or push all of them in the ocean.

ÜberJumper

I, Claudius posted this link in the lounge.

http://www.rollingstone.com/news/sto...ion=6.0.12.104

Brice-RX8

Ok cool, I just thought I might be losing my mind or something. Thanks.

Im_DANomite

iTrader: (1)

i read somewhere in Time magazine that the avg. price for regular gas in the UK was almost $5 a gal. where as in the US, the avg. price for reg. is around $2-$2.50. it's really not that bad if you think about it. a bottle of deer park water (i believe its less than 12 oz.) is about $1.25. that's a lot for some friggin' water when you could just buy one of those pur brita filters. don't get me wrong...i liked my premium gas when it was under $1. but even though some of you have used gas with a lower octane rating and had no troubles...i will still stick with my 93 for now. the cost of gas doesn't really bother me all that much.

i also heard somewhere that since many car manufacturers are now turning to make hybrid cars, instead of raising gas prices, "big brother" will start to charge us by the mileage. anyone want to clarify? although i'm pretty sure this change won't go through since, IMO, it is an invasion of privacy.

Missile

Okay, after reading that article, I think I want to go stick my head in an oven... assuming there's still some gas left that is.

ÜberJumper

hehe it's ok, the gang in the lounge where that link was posted is starting a pirate ship. YARRR

valpac

iTrader: (2)

Still saw a fair number of 8's in London. Apparently a great car is hard to keep down.

Aseras

well what's a tankful of gas at $75 where you can make a million a year and live paycheck to paycheck?

RX4life

oooohhhhhhhhhhhhhhhhhhhhh... :o

well i learnt somethinnew todayyyy...so just to get to the point..i would theoretically get worse mileage by using higher octane??

MX6_2_RX8

Yup

Swagman

I read in the last week or so, that an analyst with Goldman-Sachs, I believe, predicted the price of crude will hit $105 a barrel within 3 years. It's $55 a barrel at present.

Do the math!

MX6_2_RX8

OK, currently crude oil accounts for 52% of the cost of a gallon of refined gas (average price over all grades). So if gas costs $2.20/gal, $1.14 of that is for crude and the rest is for taxes, refining, marketing, distribution (which will go up some but I’ll only do the first order calculation). $105 is approximately a 100% increase so we should expect the crude portion to jump to $2.28 added to the $1.06 we had for other than crude costs we get a price/gal of $3.34/gallon. Now, if you invest in oil futures and double your money when the price jumps to $105 you will have enough to buy all the gas you want. Or, if the price settles back down you’d lose all your money and everybody would get back to paying $1.80/gal after the media is done hyping the s**t out of the oil prices.

Please excuse me, I’m bored, I’m headed off on vacation next week and it is Friday afternoon.

policyvote

As RG said, NA rotaries love low octane. With less detergents and a lower ignition resistance, low octance gas combusts more quickly, and the flame front moves through the combustion chamber faster. This helps to compensate for the rotary's bizzare and ever-changing combustion chamber shape. Old NA rotary racers used to use like 85 and 84 octane . . .

Of course, the modern 8's ECU plays with the A/F and timing as you approach the knock limit, so the end result of switching octanes will vary by car, driver, altitude, humidity . . .

Peace
policy

spork

gas in baker (on the way to las vegas)