Howdy guys -

Just wondering, does putting premium fuel in the tank make a big difference for the car?

I was at the gas station last night, and payed $23 to fill the car up with premium stuff, been using premium ever since I bought the car and she runs great (I live in California, so that's why it's so damn expensive).

But I am wondering if it is worth it?

Should I stick with premium? or will regular work just as good?

Thanks


------------------
Year: 1990
Make: Chevorlet
Model: Z-28 / IROC-Z
Engine: 5.0L V8 TPI
Trans: 700R4 Auto
Additional:'92 Z-28 Rims, T-Tops, Tinted Windows, Edelbrock Suspension Kit, Edelbrock Catback Exhaust (Chrome tips), K&N Air Filter

 

In my '89's L98 w/timing set at 6* BTDC (factory) I run regular with no pings or knock retard. At $2.00 + a gallon, I feel your pain as well.

 

1st off....anything less than 89 octane isn't suitable for a lawn mower.

Aecondly...here in Detroit the gas is around $1.84 for 93 octane and $1.99 for 94 octane.

My car takes about $23.00 to fill with 94.

I can tell you this also....

A computer controlled engine runs on a knock sensor. It advanced the timing curve until it senses knock. If you have higher octane, the car is less prone to knock, will run more agressive timing curves, and therefore be more efficient.

So putting in better gas is actually cheaper in the long run.



------------------
Mike L.

"If it feels good - stay in it "

1987 IROC Z TPI 350 A4 3.27 Borg-Warner.

Mods: 2300-2500 Stall Converter, Shift Kit(GM parts), TPI Specialties Stage 3 PROM, Modified Airbox w/ K&N's, homemade cold air, Relocated MAT sensor, Gutted MAF, 160* thermostat, Accel 8mm Wires, bypassed TB coolant, Flowmaster 3 chamber single 3" in/out muffler, 3" MAC mandrel intermediate, custom dual !cat Y-pipe. airfoil, ported plenum. !smog

http://www.MichaelLasiuta.home.att.net

**BOYCOTT LAPEER DRAGWAY**

 

So you really think that you're saving better than 25 cents a gallon by running higher octane fuel? Heck, you may as well run airplane fuel, eventually you'll get 900 miles to the tank

 

Atcually, if you can discipline yourself to keep your foot out of it, you'll get better fuel mileage with lower octane fuel. If you can't stand it and have to throttle up just 'cause, your mileage will be worse. There is more heat engery and a faster conversion of the air/fuel vapor mixture to the combustion gasses with lower octane fuel. Unfortunately, if you throttle up to the point where you experience detonation, teh knock sensor will detect it and trim ignition timing back so that any gains are eliminated, and you actually retard spark until you get worse mileage. If you drive like there is a raw egg between your foot and the accelerator pedal, you can coax some decent mileage out of the V-8. If you drive it like it was built to operate, you'd better use higher octane or water injection, or some means of slowing the combustion process.

 

I always put in the premium gas. I like Amoco the best.
It is just a thing with me, I have always used premium, and always will. I just think it burns cleaner in the engine.
Take care
Mike

------------------

Smokin 1989 GTA- Bone stock except for exhaust. (no catalytic-stainless pipe into Flowmaster 2 chamber.

 

hey 8mike9, you're from the san joaquin valley huh? send me an email, i bet we dont live too far away

tru69cugar@aol.com

 

Please qualify this statement, sorry, it makes absolutely no sense. Higher octane gasoline is not 'better' gasoline.


However it is related to the base timing. The computer does have an upper limit for additional timing. This is why it is so critical to set base timing. The timing cut programmed into the computer is drastic. Once knock is detected the computer cuts LOTS of timing. Another reason why setting base timing is so critical, too much and you hurt yourself in the long run.

Dependent upon each individual situation. I can cut my base timing, lose a bit of power, and get better gas mileage. Economically speaking, the lower, cheaper gas mileage is the winner every time.

------------------
"Question with boldness even the existence of a God; because, if there be one, he must more approve of the homage of reason, than that of blind-folded fear."

-Thomas Jefferson

 

so.......you mean the 94 ultra and *104 octane additive that I've been using really doesn't add 25HP??

'84 Trans Am ,mods: fuzzy dice

 

octane booster is the biggest farse there is. Sure it boosts octane...but high octane=fast is totally different than high octane=makes my car fast! Higher octane is needed on High compression/Supercharged motors/lotsa nitrous motors. It goes back to the universal gas law. If you compress a gas, it gets hotter, if you compress a fuel/air mix really fast like the motors above, the mix will explode, w/o spark, causing a condiiton called knock/spark knock/ping/etc...which is bad for the motor! Higher octane ignites at a higher temp, keeping the mix from igniting early. High octane does not add power to the car, rather it is necessary in high power cars


------------------
Corry Lazarowitz
clazarow@voicenet.com
clazarowitz@hotmail.com
1987 Pontiac Trans AM (GTA?) 350 or is it a 305?! TPI
SLP 1 3/4" headers, 3" cat back (stock cat
MSD ignition.
MSD Blaster SS coil.
3.73 Rear end gears
Accell 8.8 Wires
Bosh +4 Spark Plugs (Don't know if they really help but hell!)
Holley AFPR
Race Built Automatic trans ('vette servo, shift kit, tightly packed clutches)--just needs titanium gears now!
Newly gutted cat (the car gutted it's own cat!)
Hypertech Chip (Just found out I had it! :eek
More soon when funds are avail...

 

Damn I wish we could go back to these days!!!!!

 

Well being that half of these cars have a lower compression ratio than my weed wacker, 87 will do just fine...

 

Here in Colorado you can't GET anything higher than 91 - and regular is 85. I've had 4 3rd gens, 3 of 'em with 350 TPI's. and they ALL ran on regular with no problems. (sea level or 10,000ft) The rule of thumb is - run it on the lowest octane that it won't ping on. Anything else is a waste of money. Hi compression, modded engines are another story of course, but for our stock cars, regular will work just fine.