gjrock
Bronco Guru
I have a pretty built 302 and run regular.What does everyone run?I used to run premium but I dont notice a difference.
I have a pretty built 302 and run regular.What does everyone run?I used to run premium but I dont notice a difference.
Interesting...
I have been running 93, but on my next fill up will probably try a lower octane and see how she stomachs it.
I just assumed that given the age the higher octane would perform better and we all know what they say about assumptions.;D
i have to run premium. it rejects low or mid grade, it starts pinging on me. just paid $3.46 a few minutes ago.
I built a hot little street Karmann Ghia in high school, small displacement huge heads, lumpy cam, dual 40mm carbs..., it wouldn't run on anything lower than about 110 octane, I used to have to mix racing fuel with premium, otherwise it wouldn't even run. I sure learned my lesson there. Now I do my best to stay with the cheap unleaded if I can.
Just be glad you aren't paying 3.70 for regular like we are in Sol Cal.
If you are running higher octane than just what is required to avoid pinging with a good timing advnace range..it is money wasted. That said, the later-model EFIs with knock sensor will run low-grade fule without pinging but the mileage goes down (as does the oomph) due to the ECM not allowing as much ignition advance...so in that case, yr not really saving money. Found that out quickly with my Expedition and since have always run 89 vice 87 because of it. But for an engine without timing controlled by ECM...just enough octane to avoid pinging is all ya need....more does little or nothing for performance.
'Octane' refers to the propensity of a fuel to ignite due to pressurization and also its combustion velocity after it does. Burn rate modifiers, like lead octoate in the good ole days, Copper salicyclate, lead beta-resorcylate, toluene, etc produce kinks and even plateaus in the fuel pressure-ignition curve, said curve heads quickly upward with increasing combustion pressure. Early 19th century gasoline with no burn rate modifiers would self-detonate at CRs in the range of 5 or 6:1! Note that none of that 'stuff' affects or increases the amount of energy in a gram of fuel...it only affects the pressure at which it wants to kick off on its own, without a spark to ignite it (detonation/predetonation) or if its burn explosion velocity is too high after it does ignite (pinging or 'spark knock').
Ok..got carried away. Class over for today.;D