Regular vs. Premium

[MrMojoRisin681]

8.5:1 Compression for me so I use regular.

[81DaytonaPaceCar]

The computer retards timing and gets rid of pinging and knocking.

You can put premium in whenever you want with the regular they'll just mix.

True.

However, there are some consequences here. The computer will retard timing to reduce pinging/knocking, but will do so at the reduction of horsepower.

Higher octane fuels do primariy two things:

1. Reduce the tolerance for knocking and pinging. Hiigher octane fuels will allow you to comfortably run a higher compression ratio due to the burn rate being more controlled (it's the pre-detonation or lack of a full burn that hurts you...higher octane reduces this tolerance).

2. Allow better fuel stability in high temperature operations. If you have an issue with vapor lock or fuel beginning to vaporize before reaching your intake/carb, try running a higher octane fuel.

Long story short, higher octane fuel does not create horsepower. But it does better preserve horsepower at higher temperature operations (i.e. hot engines bleed less HP with premium fuel).

You CAN run any octane fuel in just about any engine. But it will feel sluggish when you do it.

In the winter, for a LT1 or LS1, I'd guess you can probably run mid level without losing much. On a 95 degree summer day, run premium. If you're super or turbo charged (i.e. even more engine heat), run premium all the time, regardless of displacement or compression.

This is just a guess, but if it was me (and, yeah, I'm anal retentive), anything over 10:1 I'd run 93. Anything over 11.5:1, I would run 101+ to keep all that wonderful horsepower you spent all that money on.

I like throwing in a few gallons of 101 or 110 during really hot summer days. Makes a world of difference.

110 Turbo Blue is simply amazing stuff.

$4.79 a gallon, and worth every penny for motors that see higher compressions.

[JoeliusZ28]

the previous owner said my car spark knocked on 89, so im never even gonna try it.

[SS4Matt]

yeah i only run premium.... i only fill up at the shell up from my house, or BP/Amoco...... they seem to have the best gas. if i even get that 92 octane premium my car runs like crap. it will idle all over the place, either idle really high, or really low. but with shell of BP it runs the best, and the shell V-Power advertisement for better gas mileage is definatly true. i can get on average 20 miles more on a tank of shell vs. Mobile

just my $0.02.... i look at the premium the same was as whoever else said it...jasen i think?...that it's only a few more bucks a tank... it's not that big of a deal for my most valuable possession

[Yoeasy69]

True.

However, there are some consequences here. The computer will retard timing to reduce pinging/knocking, but will do so at the reduction of horsepower.

Higher octane fuels do primariy two things:

1. Reduce the tolerance for knocking and pinging. Hiigher octane fuels will allow you to comfortably run a higher compression ratio due to the burn rate being more controlled (it's the pre-detonation or lack of a full burn that hurts you...higher octane reduces this tolerance).

2. Allow better fuel stability in high temperature operations. If you have an issue with vapor lock or fuel beginning to vaporize before reaching your intake/carb, try running a higher octane fuel.

Long story short, higher octane fuel does not create horsepower. But it does better preserve horsepower at higher temperature operations (i.e. hot engines bleed less HP with premium fuel).

You CAN run any octane fuel in just about any engine. But it will feel sluggish when you do it.

In the winter, for a LT1 or LS1, I'd guess you can probably run mid level without losing much. On a 95 degree summer day, run premium. If you're super or turbo charged (i.e. even more engine heat), run premium all the time, regardless of displacement or compression.

This is just a guess, but if it was me (and, yeah, I'm anal retentive), anything over 10:1 I'd run 93. Anything over 11.5:1, I would run 101+ to keep all that wonderful horsepower you spent all that money on.

I like throwing in a few gallons of 101 or 110 during really hot summer days. Makes a world of difference.

110 Turbo Blue is simply amazing stuff.

$4.79 a gallon, and worth every penny for motors that see higher compressions.

agreed..

i do however like to do a 1/3 to 2/3 mix of 110 and 93 octane from time to time.. gts it nice n clean.. also if you looking to boost milage or really cleansth the crankcase.. seafoam works like a mutha fer... i love that stuff..

[JoeliusZ28]

just my $0.02.... i look at the premium the same was as whoever else said it...jasen i think?...that it's only a few more bucks a tank... it's not that big of a deal for my most valuable possession

[phoenix_rising]

Mid-Grade here.

[DETROITMUSCLE]

premium, peroid.

[transampimp]

When my car was stock I used regular all the time. I didn't really notice a big difference in power when using premium. However she would run a bit smoother. I swithced to using nothing but premium after I had my computer tuned and LT4 knock module installed. BIG DIFFERENCE

[thursday12889]

Yeah, I only use Shell gas. I don't trust BP or Admiral. But when whoever it was posted that list, should i run premium, when my engine gets hot, its almost like its misfiring, I can be almost flooring it and it won't do anything until I put it all the way down. Would that be because the fuel is evaporating too quickly? And here in Three Rivers, they sell Torco 110 octane for 2.59 a gallon. They are losing their ass on that.

[greenmachine]

seafoam works like a mutha fer... i love that stuff..

not to steal the thread or anything but i allways here about this seafoam stuff.. were can i find it? i looked at autozone but they didnt have it

[02hawk796]

I did not read the whole thread, so sorry if this repeats.
First of all, your Owner's Manual says to run premium gas, so if it's a Firebird then be sure to run to good stuff, otherwise it'll take 2-3 full tanks of good gas before it runs right again. If you're driving a Camaro, slow octane gas is fine, you're gonna be slow anyhow
Second, you are wasting your money if you buy low octane gas.
figure what your miles per gallon is. figure what your price per gallon is, from the 93 octane down to the next lower level.
you can figure things out for yourself, but for this post lets assume that 93 octane is $3.00 per gal and 90 octane is 2.97 per gallon.
lets assume you get 25 mpg highway (if you keep your leadfoot off) on the 93, and the 90 octane will only decrease your mileage down to 24mpg.
Assume you top-off with about 15 gallons each time.
15gal of 93 at $3.00 is $45. With 25mpg this 15 gal gets you 375 miles, for a economy cost of 8.33 miles per $ of gas.
Using the 90 octane fuel (assuming only a loss of 1 mpg, which in reality will be much bigger difference) at 24mpg, that same 375 uses 15.625 gal which, at $2.97 would cost $46.41 (it costs more) for an economy cost of 8.08 miles per $ of gas.
Not to mention that the extra .625 gal of 93 octane would have gotten you another 15 miles further, allowing you to wave at your silly 90octane brethren as you passed him at the pump station.

[02hawk796]

Yeah, I only use Shell gas. I don't trust BP or Admiral. But when whoever it was posted that list, should i run premium, when my engine gets hot, its almost like its misfiring, I can be almost flooring it and it won't do anything until I put it all the way down. Would that be because the fuel is evaporating too quickly? And here in Three Rivers, they sell Torco 110 octane for 2.59 a gallon. They are losing their ass on that.

You should be buying that like it's going out of style. Should have enough extra power to overdrive all the time.
For the performance problem , your vehi8cle is not listed - have you cleaned your sensors? use alcohol and cotton swabs to clean the filaments.

[JoeliusZ28]

i would have bought like 50 gallons of that shit. run it in the dirt bike or something...

[thursday12889]

is it possible to run 110 in my car?