Vortec Max minimum Octane
Oct 1, 2005 | 08:19 PM
#12
TECH Veteran
Joined: Sep 2003
Posts: 4,534
Likes: 3
From: Las Vegas, NV
this is the info directly from the gm dealerworld manual.
Gasoline Octane
For all vehicles, except those with the 6.0L V8 engine (VIN Code N), use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, you may notice an audible knocking noise when you drive, commonly referred to as spark knock. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, your engine needs service.
If your vehicle has the 6.0L V8 engine (VIN Code N), use premium unleaded gasoline with a posted octane rating of 91 or higher. You may also use regular unleaded gasoline rated at 87 octane or higher, but your vehicle's acceleration may be slightly reduced, and you may notice a slight audible knocking noise, commonly referred to as spark knock. If the octane is less than 87, you may notice a heavy knocking noise when you drive. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. Otherwise, you might damage your engine. If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, your engine needs service.
Gasoline Octane
For all vehicles, except those with the 6.0L V8 engine (VIN Code N), use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, you may notice an audible knocking noise when you drive, commonly referred to as spark knock. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, your engine needs service.
If your vehicle has the 6.0L V8 engine (VIN Code N), use premium unleaded gasoline with a posted octane rating of 91 or higher. You may also use regular unleaded gasoline rated at 87 octane or higher, but your vehicle's acceleration may be slightly reduced, and you may notice a slight audible knocking noise, commonly referred to as spark knock. If the octane is less than 87, you may notice a heavy knocking noise when you drive. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. Otherwise, you might damage your engine. If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, your engine needs service.
Oct 2, 2005 | 10:07 AM
#14
TECH Veteran
Joined: Sep 2003
Posts: 4,534
Likes: 3
From: Las Vegas, NV
Originally Posted by Mort
One other thing to remember, aside from the price difference for the premium gasoline, is that the 6 will get 12.5mpg average empty and the 5.3 will get around 17.5mpg.
a 6.0L in a half ton gets much better than 12.5. hell, you can get that with a radix and a good size cam on a 6.0L in the awd version.
Oct 2, 2005 | 05:45 PM
#16
TECH Enthusiast
Joined: Mar 2005
Posts: 564
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From: Dallas
I had a 04 2wd SS, ran fine on 87 in oklahoma. Beat the snot out of it(literally, you'd be amazed at some of the stuff this truck can do on and offroad) every second, no knock for the 20K miles i put on it in a year (now its sold). Did put 91 in when it got over 100 degrees outside just in case though.
Oct 2, 2005 | 06:00 PM
#17
TECH Veteran
Joined: Sep 2003
Posts: 4,534
Likes: 3
From: Las Vegas, NV
Originally Posted by OKcruising
I had a 04 2wd SS, ran fine on 87 in oklahoma. Beat the snot out of it(literally, you'd be amazed at some of the stuff this truck can do on and offroad) every second, no knock for the 20K miles i put on it in a year (now its sold). Did put 91 in when it got over 100 degrees outside just in case though.
04' 2wd SS???
