My 1974 Chevy Nova 350 4bbl has a sticker on the inside of the glove box indicating 91 octane ROM. Is todays regular 87 good enough? The compression is 8.5:1, low.
2006-12-28 06:47:03 · 4 answers · asked by cadet 2 in Cars & Transportation ➔ Maintenance & Repairs
The sticker probably says 91 octane RON ( for "Research Octane Number"). Present day gasoline pump octane ratings are the sum of RON and "Motor Octane Number" divided by 2. This is sometimes seen on gasoline pumps as: (R+M)/2. RON is usually a higher number than MON, so if both are averaged, 91 octane RON is equivalent to about 87 pump octane. So, as has been stated, use 87 octane unless the engine starts to knock under load. If it does, go up in octane until it stops.
2006-12-28 09:19:25 · answer #1 · answered by db79300 4 · 0⤊ 0⤋
Your nova should run fine on 87 octane,if it starts to ping under heavy acceleration you may have to move up in octane.
2006-12-28 14:53:57 · answer #2 · answered by johnnybegood 3 · 0⤊ 0⤋
Youy should be fine with 87 right out of any pump. Like someone said, if you hear something under heavy acceleration, then try the 89.
2006-12-28 15:32:52 · answer #3 · answered by jdm 6 · 0⤊ 0⤋
try it if you hear pinging , use premium
2006-12-28 14:50:23 · answer #4 · answered by sterling m 6 · 0⤊ 0⤋