: High octane



Loud 93 STS
11-05-03, 01:54 PM
I have a place where I can get 105 and 110 octane gas for just about the same price as 93. Is this too high of an octane rating for the Northstar? I was thinking it might be a bit much. Just wanted more opinions.

Thanks
Matthew

Freep
11-05-03, 05:46 PM
I have a place where I can get 105 and 110 octane gas for just about the same price as 93. Is this too high of an octane rating for the Northstar? I was thinking it might be a bit much. Just wanted more opinions.

Thanks
Matthew

I had some experience in this with mine. It tends to cause knocking and the sensor picks this up. It will compensate and you will experience rough idles and periods of unconsistant idle rpm's. That is my experience, it may be different for you. I might of just had bad gas that day too so you never know.

Katshot
11-05-03, 05:51 PM
Using fuel with THAT high octane rating will just max out the timing curve on the computer and beyond that, not much else.

elwesso
11-05-03, 07:39 PM
IMO, its a waste of money...... Also, it could be leaded, and thats no good on the cats.......

Katshot
11-05-03, 08:20 PM
Good point Wes. You're right, all the SUPER-high octane stuff I've seen IS leaded.

Ultra Slow
11-05-03, 11:20 PM
That does sound like leaded gas... Dont do it! As far as higher octane on the NS, dont bother. I have run Phillips 108 unleaded in my STS, simply because I had it for another car and tried it, it makes no difference at all but smells good! If you raised the compression on the NS a full point, you might have to add like 1 gallon of 108 to every 10 gallons of 93, but thats about it.

Loud 93 STS
11-06-03, 12:08 AM
Thanks for all the feedback. It is unleaded, but from everything here, it does'nt help at all. I'll just stick to the 93 from Kroger. And as for the cats, elwesso, all I have to say is "What cats."

DaveSmed
11-06-03, 12:30 AM
Where do you get this gas from for the same price as 93? Shame that it's unleaded, but oh well.

JJhomer83
11-06-03, 12:37 AM
Where do you get this gas from for the same price as 93? Shame that it's unleaded, but oh well.

Dave FYI you can get 93 and 94 and sometimes 96 i think for the same price or cheaper than what is "around" the are per say. Go up north i find limeric to be cheap, bethlehem, qtown, etc... also some of the far out gas stations do carry race fuel and its cheap b/c hill billies like dem old cars

zonie77
11-06-03, 12:50 AM
Where are you getting this gas?
Av gas??
Av gas is rated somewhat differently but is still higher octane. Av gas also doesn't correspond exactly to automotive gas as far as addditives and spec gravity.
If it's av gas it normally runs OK but if you modified carb and timing it didn't give exactly the same results.
The benefit of high octane is resistance to knocking under high compression. No real benefit in lower compressions than max. So if 110 octane supports 12:1 not a lot of benefit if your running 10:1. Higher octane gas burns slower which is the reason you advance the timing. It doesn't give you more power unless the engine is built or tuned for it. In automotive applications you might get a better detergent package with premium gas.


Let us know.

JJhomer83
11-06-03, 01:05 AM
Where are you getting this gas?
Av gas??
Av gas is rated somewhat differently but is still higher octane. Av gas also doesn't correspond exactly to automotive gas as far as addditives and spec gravity.
If it's av gas it normally runs OK but if you modified carb and timing it didn't give exactly the same results.
The benefit of high octane is resistance to knocking under high compression. No real benefit in lower compressions than max. So if 110 octane supports 12:1 not a lot of benefit if your running 10:1. Higher octane gas burns slower which is the reason you advance the timing. It doesn't give you more power unless the engine is built or tuned for it. In automotive applications you might get a better detergent package with premium gas.


Let us know.

I have never put anytthing higher than 94 in any of my personal cars. I can't see the logics behind putting something else in. If it were THAT much better it would be at gas stations all over.

DaveSmed
11-06-03, 01:07 AM
What it really wants is the lead. Dumping a bottle of lead substitute in the tank makes a BIG difference.

zonie77
11-06-03, 01:24 AM
New cars don't care about the lead. It was mainly to protect the valves. With hardened valve seats and good valves it isn't as important. Computer controls and port injection control knocking and let you run up to 10:1. A lot of the old musclecars were only running about 10:1 from the factory even if they were advertised higher. That's why they got "blueprinted" if you were seriously racing.
If you're running a 68 that's different. It still loves lead.

Loud 93 STS
11-06-03, 01:50 AM
Thanks again for all the discussion. It is one of those "hill billie" places and im not even sure what brand it is right off. I've got a couple of friends with small block chevys that run it. Maybe when I completely modify my Cad into a Super sleeper By converting to rear wheel drive and build a motor for it I'll go for the higher stuff. But that is going to be my project after I get out of school and make some money.