Sprice962
New LVC Member
Which year did the North* motors change the octane rating for fuel requirements... was it 02? And does it apply to the Deville & Seville?
Octane
- Thread starter Sprice962
- Start date
mhinchley
Active LVC Member
They all require high octane 92-93 as far as I know, because the NorthStar is a high compression engine. And it needs it. http://www.omegamotors.com/enjoy/gasoline/gasoline_07.html
http://www.omegamotors.com/enjoy/gasoline/gasoline_07.html
http://www.omegamotors.com/enjoy/gasoline/gasoline_07.html
nobodyspecial
Active LVC Member
mhinchley said:
Up to and including 1998 they required 91 Octane (highest readily available Octane in most lower altitude states), in '99 they were redesigned to run on 87.
Since 92+ is unavailable in many places GM has never advanced the timing enough to require that kind of Octane in any of their vehicles (post leaded fuels).
Other high compression vehicles that I have owned that called for, and ran on 87 Octane are my 1989 (Lucas ignition) Jaguar XJS running 11.5:1 (all aluminum V12) and my LT1 Caprice running 10.2:1 (iron headed! 350 no less).
I bet the LT1 would run on goat pee if I pumped it into the tank, it is that resistant to knock with the reverse cooling. Same motor is in the 94-96 Fleetwoods, if you want some LVC content.
mhinchley
Active LVC Member
well I guess it all depends if you are getting any knocking or pinging. I have never chanced it myself.......so really don't know. As far as recommendation......if GM reccommeds premium, it would specify that at the gas cap, and usually on the cluster. Mine is a 97 and it recommends Premium Unleaded Only, so that is what I roll with. Same with my Mark VIII. Never actually looked in the owners manual............lol.
caddyman62
New LVC Member
I've tried 89 octane in my 93' deville and I haven't had any knocking or pinging and also haven't noticed any loss in power. I don't know about going to 87 though?
