Horse power draw from an alternator

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Horsepower draw from an alternator

I see several threads about high output alternators. I also see threads about people commenting about the 3.0 and its lack of power. Here is a good article that might shed some light on some of the power loss for some people. You can figure that an alternator will draw about 1HP for every 33 amps it is putting out. So keep in mind that the more electrical items you add the more horse power it takes to run the alternator and less gas mileage you will get.
Electrical system

 

[KidVermicious]

You do know that amps aren't drawn unless they've got somewhere to go, right? Just because I have a 140 amp alternator doesn't mean I'm producing or using 140 amps when I drive around town...

And even if I was that'd be ~4 horsepower by your math. I lose far more than the equivalent of 4 horsepower due to larger rotating mass on the wheels and higher wind resistance from the lift and crossbars on the roof. I'm not worried about power loss from the alternator.

 

[fourwd1]

You do know that amps aren't drawn unless they've got somewhere to go, right? Just because I have a 140 amp alternator doesn't mean I'm producing or using 140 amps when I drive around town...

And even if I was that'd be ~4 horsepower by your math. I lose far more than the equivalent of 4 horsepower due to larger rotating mass on the wheels and higher wind resistance from the lift and crossbars on the roof. I'm not worried about power loss from the alternator.

He's trying to be helpful and his link is very informative, why the negativity?

 

[SV_Dude]

He's trying to be helpful and his link is very informative, why the negativity?

I don't think he's trying to be negative. I think he's just trying to put things into perspective so people don't get scared to upgrade their alternator.

Both posts are good points but if you're buying a 4runner with the 22re or 3.0, you're obviously not buying it for their horsepower ratings.

 

[KidVermicious]

I don't think he's trying to be negative. I think he's just trying to put things into perspective so people don't get scared to upgrade their alternator.

This. The idea that a larger-than-stock alternator will suddenly turn your motor into a slug, or even cause a noticeable hit to power under regular circumstances, is kinda over the top.

 

[ToyoTech]

a high output alternator will run less so if any hp lost is found it will be for a shorter amount of time. i would still take a high output because it will last longer due to less run time vs the stock that is always on because of all the technology we have added that wasnt around in the 90s

now where can i find a high output alt for my 3.slow

 

[KidVermicious]

now where can i find a high output alt for my 3.slow

Toyota 4Runner High Output Alternators