SlowHand

I was wondering if anyone knows of an index that rates 91-Octane fuel quality here in CA, in other words if there is a brand of gas that I should consider optimal for performance? Also, is there any kind of additive worth considering for performance?

I'm asking not because I want to thrash my car but because there may be some pinging at redline with my 91-Octane tune. Even though I rarely run it all the way into the red, I'd like to dial this out, if possible, and my tuner does not enable me to customise timing or mixture settings. I think it's about fuel quality, hence my question. Not a huge deal but I'm interested in getting your responses. Thanks.

Sprzout

I wouldn't be surprised if it IS the case, as CA's got some crappy fuel here.

Most of the fuel additives that are available as "octane boosters" are, for the most part, snake oil in a bottle. They don't really do anything except suck good $$$ out of your pocket, so I wouldn't waste your money on it. I'd try getting a tune down to maybe say, 89 octane, and then filling it with the 91 octane gas to get it to stop the pinging.

As for the octane measurements, in theory, the California Dept. of Weights & Measurements is supposed to regulate the octane levels here in California; if you ever look at the pumps when you're there, you'll see little white stickers that say when the pumps were calibrated/checked last; the octane tags should say who checked the octane levels as well, to certify that it really IS 91 octane. Now, the 91 Octane rating is usually just checked once a year or like, once every few years, I forget exactly. So, you may not be actually getting "true" 91 octane.

The only other thing I can suggest is to buy some race fuel in a drum, and mix that in with your 91 octane gas every time you go to fill up, to give you that higher octane. The problem with that, though is 1) finding a place that sells race gas, and 2) the cost of race gas (the last time I saw it, it was like, $5/gal for 104 octane, and that was a few years ago; expect the price to have gone up since then)

kenthicken

I had the same issue with my tunes. Would start pinging around 5000 rpm... and I use "top tier" fuel (i.e., not Arco / BP). Chevron. Shell. etc.

I had Brenspeed dial back the timing on all my tunes to eliminate the ping, and it worked. I suggest doing the same with your tuner. Back it off in the high RPM range by 3* or so.

I didn't really notice any performance difference with the timing dialed out of some of the new tunes, so I think that is your best option.

kenthicken

I run racing fuel in my Road Runner (believe me... it needs it!). 100 octane, $6.25 a gallon at the 76 station.

Sprzout

Proves my point right there.

Sheesh...I hope I can get a decent enough quality fuel for my Vette engine, once I rebuild it; most people I know who have stroked it have found that they either have to drop the compression or run race fuel to get the engine to stop pinging. I can't justify paying $100 to fill it up when I drive it around once in a blue moon, you know? I'd rather keep the octane lower to get something that will not eat me out of house & home to drive.

06GT4RAD

Chevron and Unocal/76 are the ONLYgasoline i run in Ca. If you want a real Octane increase product then stay away from all the crap that the auto parts stores sell. And buy this.

http://www.torco.com/cart.php?m=product_detail&p=8

RIchard

SlowHand

Hey thanks for all the good advice, gents. @ 06GT4RAD, would you mind elaborating just a little re. the product in the link, i.e. what makes it better than anything else, how you've observed the results and how much and how often do you add it to your fuel? Many thanks.

ANBAUTO

I only run 76 because ive dyno'd the gas, shell is ok along with chevron but i get most power with 76

SlowHand

Jeez, pinging at 5000 rpm is not funny at all. I have a relatively light right foot (for a Mustang driver) but that's only a moderately aggressive upshift. As we are both in SoCAL perhaps we can compare notes and help each other out.

kenthicken

A lot of people gave some good advice here, and I think the first step is to take out around 3*. Also, it probably says "Ford Recommends BP" on your gas cap - don't pay attention to that. BP is Arco in SoCal, as you know, and there is a reason it is 10 cents cheaper than anywhere else... don't use it.