what octane gas?

[k_pro1992]

383 vortec stroker. stock intake and full exhaust with lt headers. 9.773 static compression ratio and 7.965 dynamic compression ratio. will it still be okay for pump gas with iron heads and what octane should i run?

 

[SkyHighColorado]

Run at least 91 octane from a good company. Shell, Mobil, chevron....
Running anything higher than that would be really expensive.

 

[John Deere 4240]

Run at least 91 octane from a good company. Shell, Mobil, chevron....
Running anything higher than that would be really expensive.

91 octane is high round here, mine gets up and scoots more than normal running the 91 octane, however when I run a tank through with that it leaves a noticable amount of soot on the back of my exhuast tips

 

[SkyHighColorado]

I guess it also would depend on your location. For example here in Colorado regular unleaded is 85, mid grade is 87, and premium is 91. In other states its Regular 87 mid 89 premium 93 I believe.
Thats weird you get black soot on your tail pipe with 91.....maybe its for some reason not completely burning all the fuel with the higher octane. The GTR at work was dyno tuned recently, it has to run on pump gas (because we rent it out) so we cant e85 tune it or race gas tune it. Anyways, because of the aggressive tune its running with very high boost the pump gas just destroys the rear bumper with soot and it spits black fuel out.

 

[John Deere 4240]

It's hard to say why it's not burning all of the fuel, or at least for me it is. Every now and then I'll put in a bottle of Lucas oil octane booster for fun and it does the same thing. But maybe it's not soot but carbon build up being blown out. Just thinking out loud.

 

[///RAGMC]

91 or better

 

[Ironroad9C1]

If you are getting soot, you need to go back down the 87. you are not using all the fuel, but the better performance means you need to richen up a tad . 87 will be fine for the OP... far as better gas from one place or another, its false. all gas comes from the same local pipeline. shell might put 10,000 gallons into the national pipeline on a tuesday in texas and wednesday take out 10,000 gallons in new hampshire, but its not going to be the same 10,000 gallons they put in then the guy driving the contracted tanker delivers the same gas in his tanks to sevral different stations, I mean when is the last time you seen a shell tanker delivering gas to a shell station, its usually independent operators.

and how octane really works.
http://www.consumer.ftc.gov/articles/0210-paying-premium-high-octane-gasoline

 

[SkyHighColorado]

If you are getting soot, you need to go back down the 87. you are not using all the fuel, but the better performance means you need to richen up a tad . 87 will be fine for the OP... far as better gas from one place or another, its false. all gas comes from the same local pipeline. shell might put 10,000 gallons into the national pipeline on a tuesday in texas and wednesday take out 10,000 gallons in new hampshire, but its not going to be the same 10,000 gallons they put in then the guy driving the contracted tanker delivers the same gas in his tanks to sevral different stations, I mean when is the last time you seen a shell tanker delivering gas to a shell station, its usually independent operators.

and how octane really works.
http://www.consumer.ftc.gov/articles/0210-paying-premium-high-octane-gasoline

I did a lot of research on this last year to figure out for myself what gas to buy.
I found it goes in this order exxon mobil/Chevron, Shell, BP. They do not share they own there own gas and have a more advanced manufacturing process. I learned that almost all of the other brands share from the same gas source and have inferior manufacturing processes. So for me here in Colorado, the best quality gas I can buy is from Shell.

http://www.toptiergas.com/index.html

I will attempt to find some of the articles where I got this information from.....