Sunoco Fuel

A 94 CVPI can it use high octane , 50/50- Sunoco/92 octane ? Would I change plugs ?

No changes are necesary.

Thank's Way

Understand that there is no valid reason to run any octane higher than 87 with a stock engine configuration. If the engine is pinging/knocking, a higher octane can be used but is just masking the underlying problem temporarily.

If you want to gain more performance by using higher octane, simply using the higher octane will not work. Spark timing must be advanced to take advantage of it - something I just recently had some fun playing with on my car :)

By the way, 87 octane provides MORE energy than the same volume as another octane. Therefore without an appropriate spark timing, you are PAYING MORE for LESS MPG.

Thank's Blue

Understand that there is no valid reason to run any octane higher than 87 with a stock engine configuration. If the engine is pinging/knocking, a higher octane can be used but is just masking the underlying problem temporarily.

If you want to gain more performance by using higher octane, simply using the higher octane will not work. Spark timing must be advanced to take advantage of it - something I just recently had some fun playing with on my car :)

By the way, 87 octane provides MORE energy than the same volume as another octane. Therefore without an appropriate spark timing, you are PAYING MORE for LESS MPG.

i hate to disagree, but in my 95 if i run 87, it sucks it down like crazy, but as soon as i fill it up with 92 i can go for days, i also noticed it runs better as well, although i'm sure this could be one of those case by case situations, but just wanted to get my 2 cents in here :)

Then there is an underlying problem with your vehicle. Maybe your cylinders have a good amount of carbon build up increasing the compression ratio enough to cause minor detonation (ping/knock). Or maybe your HO2s need replacing.