Besides all the facts posted here, I will add that I wouldn't waste any cent on ANY upgraded alternator no matter who makes them if they still use the OEM small case.
Powermaster, NW Wrangler and some others use a way bigger ND case for their special HO alternators which came with a higher capacity diode plate and can disipate the heat better and isn't taxed by the limited temp disipation of the smaller 80 series OEM diameter case.
My 170 amp Powermaster has been worked flawlessly for more than 4 years before it give up (under extreme load with my 3 battery setup), but I had to replace only the front and rear bearings and the rectifier plate and it's again working great.
As I am aware the Toyota Tundra and Sienna OEM 150 amp ND available in the junkyards relays in the same bigger case.
It's also important to understand that any alternator no matter for which output capacity is rated, will draw the same HP from the engine at the same required load in amps. In short words a higher capacity alternator of course will draw more HP but only if you demand more current from it, and has nothing to do with fuel economy etc, is just related on how many amps you need.
The more amps you require, the more HP will draw so if your battery is charged and you have most of your electric equipment off, the HO alternator will tax your motor exactly the same as the Toyota 80 amp OEM alternator.
Just to clear this urban mith.
Powermaster, NW Wrangler and some others use a way bigger ND case for their special HO alternators which came with a higher capacity diode plate and can disipate the heat better and isn't taxed by the limited temp disipation of the smaller 80 series OEM diameter case.
My 170 amp Powermaster has been worked flawlessly for more than 4 years before it give up (under extreme load with my 3 battery setup), but I had to replace only the front and rear bearings and the rectifier plate and it's again working great.
As I am aware the Toyota Tundra and Sienna OEM 150 amp ND available in the junkyards relays in the same bigger case.
It's also important to understand that any alternator no matter for which output capacity is rated, will draw the same HP from the engine at the same required load in amps. In short words a higher capacity alternator of course will draw more HP but only if you demand more current from it, and has nothing to do with fuel economy etc, is just related on how many amps you need.
The more amps you require, the more HP will draw so if your battery is charged and you have most of your electric equipment off, the HO alternator will tax your motor exactly the same as the Toyota 80 amp OEM alternator.
Just to clear this urban mith.
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