94zgreenmachine

check the sig. When I was throwing belts and I had to be "nice" to it I would manage 17-18 MPG combining mostly highway with city driving. Average is approx. 14 MPG but my foot is still really heavy with the new set up
Sometimes when I am playing , I can almost see the gas gauge go down

RedRocketZ28

I run 89 in mine quite a bit because I am usually driving all highway and have not noticed anything. In town I will usually run 91 or higher.

SS RRR

Even if you have a HPP tuner you can still run 87 octane safely! That's what a knock sensor is for. However... doesn't mean your engine will run any more efficently and may even be less... which means worse gas mileage.
If your car is stock 10.5:1 compression then 87 will be fine. But if you are running 11:1 w/ a LT4 knock sensor then running 87 octane will do no good.

RENE95Z

I don't care if you paid $1 for premium last year and it's $3 this year. The simple fact is, last year premium was $.20 more expensive than regular and this year it is $.20 more expensive than regular. By switching to mid or regular grade, you are basically saving $1 or $2. And buying octane booster to make up for putting 87 in the tank; how much is that bottle - $2 - $3? Where is the savings in that idea? Might as well put premium in the tank. I know $2 a week will add up to $104 a year and so forth and so on. What kind of toll will this have on your engine by putting the lower grade fuel in your car and possibly causing more damage than $104, etc? Just my .02 rant.

91TPI

I run 89 in my stock 94 Z28 (except for cold air and exhaust) and get about 22/23 town and highway, or 27/28 strictly highway. Of course that is treating it nice! I drive 120 miles a day and this is what I consistently get, just my info..........Later

urbaNHunter44

mine pings bad on 87, doesnt really like 89 either. I only feed her 91 and she doesn't complain. It has 10.4:1 cr.. i don't think i want to stick lower octane in her lol

Jason E

I ran 89 in mine a couple years ago for a few tanks, and while it didn't ping, it didn't seem real happy either. I guess I could get away with it, but for the extra $.20 per gallon? That's $3 total if I ran the tank bone dry...I'll pass. Believe me, I'm going to Bowling Green (2k round trip) for the F Body gathering in less than 2 weeks...I'd LOVE for gas to cost a little less. My trip just went up about $50 in the last 2 days But to make the car unhappy? Stick with 93, for me anyway...

SS RRR

Did you see if your mph was any different than running a higher octane?

69gto96z

I run 89 in my 96 T/A which is basically stock other than exhaust and cai. No knocks or pings(knocking on wood). The only reason I don't buy premium anymore is because I am on a high school budget...

shoebox

You can run whatever octane that does not ping. Mine did not like 87 much, even stock. Lugging or loading it down with lower octane gas will make it more apt to ping.

Jason E

No, I didn't...

I tend to get excellent mileage with mine. My lowest tank all summer has been 17.5, and that was jerking around on the local cruise strip Typically I get 19 in mostly city driving...the best tank this summer has been 22, however the last Bowling Green run 2 years ago netted me 28.5 on one run IIRC

Shooting for 30 this year with my fresh plugs and wires! I averaged almost 71 MPH on the way down last year, doing mostly 78-80. This year will be a clean 75 because I don't feel like watching for cops for 15 hours straight!! That got old after hour 5 or so, last time

94_PatriotRed_Z

my car pings bad with 89 so I stick with 93, and that was when it was stock it pinged at 89 I dont even want to try it now

Cerwin Vega Fan

Thanks for the feed back guys, I'm just going to bite the bullet and run 93+. I figure if I can afford to run Royal Purple I can afford the good gas. And BTW if anyone wants cheap octane booster I found some O'Reillys, if you buy over 3 bottles you only pay a dollar bottle but I doubt this stuff has any real strength. On a different note I find it funny when I was young and stupid (senior in HS) all I did was run 87 in my car. I remember when I ran my tank down real low and filled it up with 93, even the tone in exhaust changed.

z28sinx

I don't have a choice here, we have a gas shortage on the gulf coast due to the hurricane. All I can run right now is 87. Either that or wait at a gas station for the truck to come in, whenever that is. Also, I was getting low, which previously I had put 93, and I put 87..so now I have a nice mix of 93 and 87. Not sure what it does to my car, I'll find out soon.

Cerwin Vega Fan

I live near the gulf as well but a refinery is near my location so I don't see how we could run out of gas. I guess after all the years of pollution and toxic gases some good is actually coming out of the area.