Z28LT1_Just_Nasty

Stock F-body LT1, what octane gas is it supossed to run? I never had an owner manual to this thing and I'm just curious.

aarontracy

i always run 93

Z28LT1_Just_Nasty

Is that what it says to run from the factory?

MyShibbyZ28

Factory owners manual says to run 91 or higher.

Injuneer

You can find links to .pdf copies of the factory Owner's Manual on Shoebox's web page:

http://shbox.com/pdf/manuals.html

Z28LT1_Just_Nasty

Wow, this entire time I've been running 87. Well only 3500 miles worth of driving, the thing is in the shop more then its on the road. How much of an acceleration difference would I notice using 91 vs 87? Oh and btw I have no pinging or knocking using 87.

MyShibbyZ28

You aren't going to feel the ping or knocking running 87, there is a knock sensor that retards the timing to prevent that. The accleration is ok from 87 to 91+. Don't think higher octane automatically means more power. You can only get to a certain point and then higher octane does nothing for you.

Z28LT1_Just_Nasty

Oh I know that more octane doesnt mean more power unless you have the tuning to support it. I'm just curious about that 05 Mustang GT I raced, would it have been closer lol

MyShibbyZ28

No, it wouldn't have made that much of a difference. The reason people go to higher octane is to get rid of knock retard, which in turn gets the most power possible. If you have knock retard then yes it would help, but not by much.

Jameslt1TA

I always ran 85 when i was stock....never could tell the diff between it and 91. Right now though....i run 91 since my motor is build, i would run 93 but 91 is the highest that they carry around here.

l8r
James

Z28LT1_Just_Nasty

NJ has 94, they call it supreme. I guess really its useless, the most any production car is designed to run on is 93. 94 is quite a few cents higher then 94 too.

lt1street

If you have the opertunity to use a scanner that with give you data stream you might see the differents. With the knock sensor feeling dentnation you will see timing getting pulled that mean power is suffering, the timing that you might be be losing is not going to be like 20 hp but every little bit counts!!!!

rock1501

bstieboydp

i second that lol

Injuneer

Not necessarily a problem. If he's in the mountains in Wyoming, his octane requirement will be much lower than it is for those of us at or near sea level.

NJ pumps generally carry 87, 89 and 93. Put a scanner on it. In the winter, with cooler intake air temps, the 89 may be OK. You'll only know if you check for knock retard with a scanner. In the summer, with high ambient temperatures, you will be better off with the 93. As the engine ages, carbon can build up and increase the octane requirement. You can't really generalize, particularly on an engine that's 11 years old.