Here is a question for anyone reading this thread.

What does the octane rating of gasoline really mean?

Rob

 

i filled up my SC today with super + (93 octane) and it cost me $40.00! i wasn't even on E.. close to it though

 

lol. I went to Mobil 1 today to fill up my tank. 91 is at $2.89, fill it up to around 17gal and it came to $49.49....@$#@$#%^ b/s. I hate this gas price surge. this must mean shell and chevron (ones i mostly go to) must cost an arm and a leg.

 

one time i was driving home from work and my gas light came on, and there was this gas station a block away selling 100 octane for $6pg, i put in $20 and it went up like two sticks. i'm sure some of you people in ny know of the spot, its by the greenpoint bridge

 

(R+M) x


I can't tell you off the top of my head, I will tell you the properties and meanings in the mornin.

Josh

 

Gasoline pumps typically post octane numbers as an average of two different values. Often you may see the octane rating quoted as (R+M)/2. One value is the research octane number (RON), which is determined with a test engine running at a low speed of 600 rpm. The other value is the motor octane number (MON), which is determined with a test engine running at a higher speed of 900 rpm. If, for example, a gasoline has an RON of 98 and a MON of 90, then the posted octane number would be the average of the two values or 94.

 

BTW, has anybody experienced any gain in mileage by using fuel injector cleaner/ fuel system cleaner? (typically from STP mobil etc)

 

The octane rating of gasoline is related to the burn rate of the fuel.
The higher the octane rating the slower the gas burns.

Higher compression engines require higher octane rated fuel.

You can use high octane rated fuel in a low compression engine with no problems.

When you try to use low octane rated fuel in a high compression engine the results are usually pinging and run on.

Rob

 

YES! i put in Sunoco Ultra 94 and the Fuel System Cleaner and i have good gains...but i only do it every 3000 to 5000 miles....

CEO

 

my bad your right..... That was last night and I was about to fall asleep at the key board.

Cheers

Josh

 

i've noticed quite good milage lately on my sc... right now i'm at 285 miles after 3/4 of a tank, still 1/4 left! by my calculations, i should be able to get around 380 by the end, providing i keep up the highway miles. what i'm getting at is, maybe the best thing we can do to help keep fuel prices down is to simply watch the lead foot and avoid that stop and go traffic if you can. every little bit helps!

 

I get like 230-240 miles on my full tank, and thats filling up with 18 gallons after that. I recently put 89 in my tank because I counld't stomach the 93 price and I was doing interstate driving and got about 146miles before I got to half-way. I was also crusing at about 80-100 the whole way there (more at 100 though ). I'll have to see at the end if it really made a difference compared to the other milage I usually get on the interstate which is usually 18mpg. I get around 14-15mpg in the city which SUCKS! BTW I have a 92 SC300 5spd. I've tried driving slow and not reving it up and shifting at 2500-3000 and also fast 4000-5000 shifts and it seems to make maybe a .5mpg difference in the end, not much at all.

 

Haha same here, my track **** is a nissan 240sx that im rebuilding! (technically I have 2... I managed to put a tire through the firewall in one so it automatically became a parts car! (Even though I fixed the lexus.. im not tinkering with something as critical as a firewall.)

 

Well I put some 87 in for half a tank just to see if that made any difference since I didn't notice any with the 89. I think the car is slower...

A suburban beat me at s toplight for the race to the interstate ramp, granted I did shift at 4k and didn't gun it to start with but I mean damn, i was pissed. I'm filling up with 93 for now on again!

 

Yeah, what he said

JK, thx for the explanation - I didn't know that. Good to know

Peace,
Jonny