Dennis Wilson

Most US fuel is now rated on the M+R/2 scale so an 87 RON would be just over 88 at the US pumps. Running 91 or 93 octane will only help performance IF the timing is advanced to take advantage of the longer/slower burn.

Dennis

88porsche928

they sell racing fuel at most motorcycle stores is over $50 for 5 gallons, if i did not take my car to a chop shop I would buy 2 cans of it and see if it makes a difference

justin

Jim bailey - 928 International

Since aftermarket chips advance the ignition timing and the 85-86 lacks knock sensors run the high octane to avoid pinging...and protect the engine.

mark kibort

Isnt that the TRUTH!! after all, who wants to be just, "Regular" ?

so funny, that folks wont use, "cheap" gas, because the quality is suspect.
doesnt it all come from the same refineries? what are the tanks "cleaner" with cheveron?

I still get a little brand suspicous, and only use cheveron or 76 on race day (sometimes shell) I have no idea why i avoid the other brands. Thought of the unknown?????

I think i remember doing a dyno run after i put in some race gas. I dont remember there being any difference.

mk

Sharkbody

It's like saying you don't need meds because you feel fine on them. Certain setups are unaffected by low flashpoint fuels, but even those, some of which have accumulated a moderate degree of carbon buildup over a six figure lifetime, can avoid dieseling and other issues with a bump in octane. G

Jim bailey - 928 International

Carbon buildup ?? drive it like a Porsche and you have no worries seriously I have lost track of how many heads I have seen and there is rarely much carbon in a 928 engine. The old ethel gasoline was red due to the dye which was added to warn people it was leaded full and toxic but color is still added to some fuels to make them "special". Burning higher octane than needed does not hurt anything other than the pocketbook.

Sharkbody

Can you imagine naming your daughter Ethel. G

Jim bailey - 928 International

Interesting quote on Tetra ethel lead.."DuPont Corp. Report on Ethyl, 1936

It is also of interest to recall that an important special motive for this [tetraethyl lead] research was General Motors desire to fortify itself against the exhaustion or prohibitive cost of the gasoline supply, which was then believed to be impending in about twenty-five years; the thought being that the high compression motors which should be that time have been brought into general use if knocking could be overcome could more advantageously be switched to [ethyl] alcohol. " So 1936 plus 25 years means about 1961 our Gasoline supply was exhausted...... !!

Sharkbody

I understand the technical argument, as it applies directly to "represented" Octane values. I suppose, in light of all the possible diluents out there, that we should err on the "plus" side.

Jim bailey - 928 International

George with so many people critical of the oil industry do you really think they are going to risk a huge penalty /law suit by selling gasoline with less than the stated octane ?? That would be really , really dumb...

Sharkbody

Jim, I understand your argument. remember, however, that the biggest emphasis is on certification of pumping volume.

jon928se

"leaded fuel and toxic"

I seriously doubt one could drink enough petrol for the tetraethyl lead content to be toxic - you'ld already be long dead from petrol poisoning or on fire.

Nine2Eight

It is my understanding that raw gasoline as it leaves the refineries is all the same. What makes the "brand" are the additives that are added at the regional tank stores where the distribution trucks fill up. I would imagine there could probably be great variances in the quantity and quality of of the additives when comparing a Chevron or Mobil to a 7/11 or other Joe's Discount brand of gasolines.
Then again, the only thing I REALLY know about gasoline is "Never suck too hard when you siphon!".

Nine2Eight - Tampa Bay

DSC928

Good advice.