I'd certainly like to be able to at least have the capacity to run everything that is installed on my car at full blast at idle at the same time, like you can on a modern car. The only thing that seems to upset my colorado is when the ABS comes on and the engine is down at idle since the clutch is in.

I also cross-referenced the alternator that is on the car right now that i picked up from an 83 slant six truck. Turns out its a 65amp squareback unit, Duralast DL75334.

If I use the tech archives for a listing of common current draws for items in the vehicle, I would have currently:

Component
AMPS

Backup Lights 4.20
Headlights 8.40
Heater -Defroster 10.00
Instruments 1.00
Instrument Lights .96
Ignition 2.00
License Plate Light 1.18
Parking Lights 1.26
Stop Lights 4.20
Tail Lights 1.81
Turn Signal 4.20
Windshield Wiper - Electric 4.00

for a total of 43.21 amps, and probably take 4.2 amps off for the backup lights, so 39.01 amps

I also have a 140 watt stereo, so say we were at 14.4v, that's an additional 9.7 amps. That would easily bring my total to 48.71 amps. That being said, I know the stereo doesn't always draw this much but I like to rock out just like everyone else. There may also be even more current dissipated by the older wiring that exists to some of these items.

I'd love to see an actual curve on the small Toyota denso if anyone has one for comparison. They do typically come with GOOD aftermarket reman alternators.

I do know that if I got the 12si 94amp to fit, i'd still have plenty of headroom for future add-ons...even at idle. I'm also very likely to drive this car a lot, even at night, and use everything including the wiper motor, radio, head lights, etc all at the same time.

If my 89 Denso didn't have the output stud where its located, that would have likely worked ok.

Just trying to get some discussion going.