Quote from another forum...I have always run 91 as thats what we have in GA. many Vette's over 100K miles with no issues...........

You guys running 93 gas better not do that every tankfull. You run the possibility of burning a piston or valve in the process. Those 350's innerds were designed for optimal efficiency using regular juice. It won't hurt to use 93 once a month, as I do in my Vette, Charger and Mach 1, just to keep their vocal cords clean.




I'm looking for any of your comments on this...

 

I run 93 in my '82...the old girl needs the extra juice I figure. This is my second '82, the first one saw over 150K miles, this one is a garage queen with only 28K but she still gets the good stuff as does the Z16...can't have the Z thinking it's better than the '82 now can we...

 

Why would it burn a piston?

 

I run 87 in my 1980, I've tried 93 and it makes no differance. You know an 80 motor in a vette is the same thing they put in a Caprice and many yellow cabs, what gas do you think cabbys use?

 

you need high octane for more compression or more timing advance or both. stock engines from 75(maybe even lower)-82 can run on regular.running high octane in an engine that doesn't need it is just a waste of $.20 per gallon (not that big of a deal) but running low octane gas in an engine that needs high octane will cause damage.

 

Interesting...at 9.1 compression in the 78,I should have been burning 87 ??? Guess what..it has never seen 87 octane...just 91....guess I'll blow a piston soon,after 27 years...chuckle...

Doubt that computer makes any difference on the 82 and octane it uses...

 

And another reply about how high test will do harm ....

Ok guys. As for a reallity check.

Yes running anything higher then 89 octane in our '82's will hurt your engine, foul up the fuel pump/filter, ecm unit runs car richer, maybe but not showen in tests might drop a cylinder and running the boost octane will not do anything but put lower emissions on the A.I.R. You say' Waste of money for the 93 octane and boost'??? YES... True and fact. Our engines where tested with 87 octane but as we all know it pinges our pistons on the up hills. I for one always run 89 octane for I hate the sound on my hills I drive. But as we all say' use your own judgement'.


OK this was my come back

Not meaning to start an issue over fuel octane.

However, I can find no warning about the use of higher octane fuels in the owner Manuel I do find many warnings about using only unleaded fuel. In fact, if you read Fuel Requirements in section 2-4 it states you should use an unleaded fuel with a rating of at least 87 octane.

Now in your defense it also states that using a higher octane rating than that which allows occasional spark knock is an unnecessary expense.

I see no warning from GM about a higher octane fuel creating any issues with internal parts...I also would like to know how octane would foul up a fuel pump or filter? as for the ECM it controls the fuel curve based on readings from the TPS, than the O2 after fuel is burned along with a few other sensors.

I guess I could go on but I will wait for a reply to this first.


Guess I have been fouling corvette motors for the last 30 years

 

Wow... what a newb. All a higher octane does is prevent pre-detonation. Essentially it would be LESS likely to ping with higher octane. He's so fulla crap his eyes are brown.

 

The quote from original poster: "It won't hurt to use 93 once a month.."

Fuel lines, electric fuel pumps:just watch out for ethanol....

 

Holy load of BS batman

 

I thought that higher octane just had a slower burn rate, hence the reason you can advance the timing with higher octane fuel (start the burn quicker). If you don't, you run the risk of having the burn continue out into the exhaust and causing headers/manifolds to glow or burn.

trw

 

And you might see a mileage improvement. I do.

 

No point in putting in a higher octane fuel than needed by your engine, be it once a month or all the time.

And if your motor designed for a certain octane is pinging using that octane, then something is wrong. It needs to be fixed, not covered up with higher octane gas.

 

Pish posh. Higher octane fuel won't hurt a thing except your wallet. The octane rating of a gas determines its resistance to detonation. It doesn't burn faster or hotter. In fact, the lower octane gas might pose more of a threat if you start to detonate.

 

The octane rating of a fuel DIRECTLY refers to the burn rate. Higher octane gas does burn slower.

A RON87 fuel means that this fuel has the same auto ignition resistance as a 87% mixture of octane (this is a trivial name, it's a 87:13 vol% mixture of iso-octane and heptane)

Pure iso-octane has a rating of 100 on the octane scale, that's why it's used as a reference.

 

As repeated several times, higher octane burns slower, it won't hurt your engine but is a waste of money if you don't need it. My 82 runs fine on 87 octane around town. I fill up with 93 when I run nitrous at the track to prevent preingnition without retarding my timing.

 

You guys actually have RON87 in europe? That's gotta be some craptastic fuel

Remember in the states it's RON + MON/2

So our 87 is probably like RON91 and MON83, or something like that.

 

The lowest grade we have is RON95, in germany you can get 91 but nobody uses that except maybe for their lawnmower

There are 3 rating systems, RON, MON (motor octane number) and PON, we have RON (research octane number) and you have PON (pump octane number) which is indeed (RON+MON)/2 .. I knew that

MON is always a couple of points lower than RON, RON looks better on the signs so that's why the thieving sumbiotches here sell us 95RON for 7$ a gallon or so

On top of that, your cheap gas has better quality control than our expensive stuff..we're being screwed over here

RON MON PON
90 83 86.6
92 85 88.5
95 87 91
96 88 92
98 90 94
100 91.5 95.8
105 95 100
110 99 104.5

 

I don't think that is correct but I'm not an engineer. The octane rating determines the uniformity of the flame front in the combustion chamber. Higher octane doesn't burn "slower", it just burns more uniformly along its flame front, resisting the urge to have small pockets of fuel ignite prematurely and not uniformly (i.e detonation). All gas probably burns at the same "rate" but not at the same uniformity across octane ranges.

 

Well, a more volatile flame front (eddy or fractal model) will propagate faster. It's not necessarily true that a fuel with a higher octane number will always burn slower, there are fuels out there (race fuels) that have high octane number and will burn quicker than lower octane numbered fuels, in reality the burn rate is not directly dependant on the octane number but they are closely related. For fuels you can get at your local gas station it pretty much holds true that a higher Anit Knock Index (PON) means it's a slower burning fuel. The octane number is the resistance to ignition.

The octane number is just chosen because of the " reference" fuel. N-heptane has a number 0 on the octane scale and iso-octane has a # of 100. That's why n-heptane is used to dillute the vol% to get a good reference without affecting the octane #. For instance a 91 PON (AKI) fuel is nothing more than a blend that tested to have similar ignition resistance as the 87vol% iso-octane reference fuel under the chosen circumstances (which differ for MON and RON, although pretty similar testing procedures)