Beware ethanol blend fuels
Thread Starter
Racer
Joined: Aug 2003
Posts: 304
Likes: 2
From: North Vancouver BC
Beware ethanol blend fuels
Hi guys,
Maybe you all know this or maybe you don't but I just want to give everyone a general heads up. Was looking to the pros and cons of ethanol blended fuels which many companies use to get the fuel up to 93 or 94 octane (Mohawk in particular up here in Canada).
The problem here is fuel sensitivity - octane ratings in North America are (RON + MON)/2
RON is more of a light load low temp test, and MON is more of a higher load high temp (i.e. higher performance) test. the sensitivity is the difference between MON and RON and in a typical 94 octane fuel, it will be around 10 (i.e. RON of 99 and MON of 89). When ethanol is blended in, this fuel sensitivity is increased - lowering MON and increasing RON. Unfortunately, for a high performance motor you wan't as much MON as possible. It seems that a ethanol blended 94 octane will act more like a straight gasoline 91 or 92. An ethanol blended 91... lookout!
Now of course this does not apply to supplementary alky injection since that will always increase RON and MON over whatever fuel you have as primary.
Just some food for through for you guys - and be careful with those ethanol blends.
Maybe you all know this or maybe you don't but I just want to give everyone a general heads up. Was looking to the pros and cons of ethanol blended fuels which many companies use to get the fuel up to 93 or 94 octane (Mohawk in particular up here in Canada).
The problem here is fuel sensitivity - octane ratings in North America are (RON + MON)/2
RON is more of a light load low temp test, and MON is more of a higher load high temp (i.e. higher performance) test. the sensitivity is the difference between MON and RON and in a typical 94 octane fuel, it will be around 10 (i.e. RON of 99 and MON of 89). When ethanol is blended in, this fuel sensitivity is increased - lowering MON and increasing RON. Unfortunately, for a high performance motor you wan't as much MON as possible. It seems that a ethanol blended 94 octane will act more like a straight gasoline 91 or 92. An ethanol blended 91... lookout!
Now of course this does not apply to supplementary alky injection since that will always increase RON and MON over whatever fuel you have as primary.
Just some food for through for you guys - and be careful with those ethanol blends.
