I just wondered... I know in the old days if you had a carburettor engine octane rating in fuel did make a difference. However, with our cars especially if tuned, does it really matter what octane fuel we use? I mean here in Europe we now have 100 octane fuel, but would filing the car with 100 versus 95 really make any difference to power bearing in mind engine is all electronically managed? Surely antiknock just retards the ignition? I guess the only advantage is better cooling (at least that’s what I heard once, the higher octane fuel does).

 

we have 110 here and i run 93 all day, i think its just better for the motor, but its way too expensive to run all the time, just a little mix w the 93 is wwhat i do sometimes. and the smell...love it.....

 

I do not think the 100 RON you speak of is the same as 100 octane fuel in the states. taywan, I would not use 110 in a car with cats..

 

100 octane fuel does make a difference in a car tuned for 93 because the knock sensors have the ability to vary parameters for fuel qualities. That said, a car that is tuned for 100 octane will see more power output on 100 than a car tuned for 93. I've used both in my car and can attest to the difference, but at $9 a gallon here for 100 octane I choose to run 93.

 

Landjet how can you tell what your car is flashed for 95 or 100? Is there a norm?

 

yea, 110octane is about $8/gal here in sc. only at certain gas sstations also..and i run the 93 from certain gas stations that only have non-ethonol also..or try to most of time.

 

a local BP sells some race gas, not sure exact octane but over a 100 for sure. My car is tune for 93, what are the benefits or harms of running a tank through the system??

 

benifits=aweswome addicting smell
harms=your bank account
lol, i dont think you would ever "harm" anything by running some high octane through

 

I'm stuck with Cali 91 craptane. So if I know I'm going on a hot run some place I put half of tank of unleaded pump 100 octane yeilding me about 95 octane with a little margin for error.

 

have a race file so if i wanna go fast (which is all the time) i use 100oct and my giac race file if i get stuck up the coast and can't find 100oct i have to change files and use 91, not fun so if anyone knows of race gas at the pump near fort bragg ca let me know , will be up there the 4th of nov. with about 100 other cars

 

The lead in the fuel will though... cats, plugs and O2's

 

correct the lean in the 110 will kill plugs and your 02s quick. its good to run a full tank of normal unleaded if you do run leaded gasoline.

terminator, you should ask your tuner what you are tuned for thats the only way to find out. also , the 100 oct you speak of is not actually 100oct, in our octane readings, its equal to 94 oct rating here in the us.

ad as larry said , it DOES matter, knock sensors will tel and increase your timing.

 

I do a mix of sonoco gt100 whenever I can... Do about 5 to 8 gals mixed w 93 sonoco or chevron or shell... I get the race fuel at the track or at a special sonoco about 15 mins from my place right outside the city. Oh and using leaded fuel like sonoco power110 will do harm as mentioned... Either run straight gt100 or do a mix... Either will improve performance, good for valves and reducing carbon deposits and runs cleaner at higher revs...I def notice a little more performance in a 100/93 mixed tank...

 

i dont run pure 110..if i do..its mixed w/ the 93 octane here.

 

Correct.