Every one wants more MPG....Read this and see how!
#51
06-15-2012, 09:07 AM
Champion
just consider it in the most simplistic manner-
- the engine doesn't enter the power band until around 2k rpm..
- the fan, when locked, saps the same energy to turn @2k rpm as it does at 650rpm
- the percentage of available power the engine is producing is much greater at lower RPM's than high RPM's..
- it takes more of the engines produced power to turn the fan at low RPM's than higher..
at lower rpm's, the engine is burdened by the fan.. at higher rpm's, the engine hardly notices the drag..
anyway- driving conditions:
on the open road, an efan will not help one bit.. the clutch fan won't hurt one bit.. neither is engaged at highway speeds unless something is jacked up with your cooling system.. the benefit of efan is in traffic- stop and go, and at speeds below 40 or so mph.. if that is the majority of your driven miles, I could absolutely see a 2mpg bump.. if the majority of your miles are on open road, i doubt you'll see any improvement at all..
just my thoughts..
- the engine doesn't enter the power band until around 2k rpm..
- the fan, when locked, saps the same energy to turn @2k rpm as it does at 650rpm
- the percentage of available power the engine is producing is much greater at lower RPM's than high RPM's..
- it takes more of the engines produced power to turn the fan at low RPM's than higher..
at lower rpm's, the engine is burdened by the fan.. at higher rpm's, the engine hardly notices the drag..
anyway- driving conditions:
on the open road, an efan will not help one bit.. the clutch fan won't hurt one bit.. neither is engaged at highway speeds unless something is jacked up with your cooling system.. the benefit of efan is in traffic- stop and go, and at speeds below 40 or so mph.. if that is the majority of your driven miles, I could absolutely see a 2mpg bump.. if the majority of your miles are on open road, i doubt you'll see any improvement at all..
just my thoughts..
#52
06-15-2012, 11:26 AM
Record Breaker
To answer the question when the fan kicks on**** its right under 30 amps. That's the readings when i was having my alt tested at AutoZone; kicked the fan on seen the 30 amp load increase then it settled down around 25amps +/-
I really can not attest to any MPG gain.. not right away. Any gains would be over a longer period of time. All we are doing with the electric fans are:
1. Help cooling in stop go traffic as the Fan clutch is only about 30% engaged at idle (from what I understand)
2. Remove the drag of engaged fan which if i read correctly is about 70-80% engaged up to about 2K or so.
That was my primary reasons to go with an e-fan. freeing up the power that is being used to drive that fan; from a stop on hot days is annoying. Now I do not have that problem. I'm not much if at all; expecting MPG increase.. if any it would be very little over a long period of time from not putting my foot off into the pedal any longer to compensate for the drag of the fan on take off from a stop.
I really can not attest to any MPG gain.. not right away. Any gains would be over a longer period of time. All we are doing with the electric fans are:
1. Help cooling in stop go traffic as the Fan clutch is only about 30% engaged at idle (from what I understand)
2. Remove the drag of engaged fan which if i read correctly is about 70-80% engaged up to about 2K or so.
That was my primary reasons to go with an e-fan. freeing up the power that is being used to drive that fan; from a stop on hot days is annoying. Now I do not have that problem. I'm not much if at all; expecting MPG increase.. if any it would be very little over a long period of time from not putting my foot off into the pedal any longer to compensate for the drag of the fan on take off from a stop.