Ive been using 89 octane in my truck. just wondering if i should be running a higher grade? my motor is a 351w, got headers and full exhaust. any suggestions?

 

You're fine running regular. Your motor isn't running high enough compression to do much but have it go out your tailpipe.

 

Run 87. Unless you have the timing dialed up....

 

no its all stock and original. just and edelbrock carb and full exhaust. thanks for the replys, just wanted to check and see if i was ok with the low octane.

 

The only time I run 89 is when I'm towing, all the rest is regular.

 

Higher octane fuel burns slower than lower octane fuels and is much better at preventing
spark knock or detonation. Most engines with around 9 to one compression ratio and a
decent timing pattern will run well on 87 octane fuel. Combustion chamber design also
plays a role in what level of octane fuel is needed.

 

Most people think higher octane fuel means it burns easier. Just the opposite is true. The higher the octane rating, the less explosive the fuel is. This is to stop it from detonating prematurely when you put it under pressure, acting sort of like diesel fuel. Higher compression equals higher pressure equals increased chance of fuel detonating before the engine is timed to ignite it, resulting in dieseling, or knocking. The power from higher octane fuels doesn't come from the fuel itself. Rather it comes the higher compression and allowing the engine to fire when it's intended to.

 

very good answers! thank you! one of the things ive always been told is like 92 octane burns fast and keeps the engine cooler due to a faster burn rate. i used to run 92 in my mustang gt, after i shot 2 spark plugs outta the heads i switched to 87 lol. dont know if it was a result to the octane level. thanks again for all the responses.