Changing alternators...will there be a difference?
 

Hi, I have a van that probably goes against the grain on this site.

I have recently installed electric steering and I have a rather large stereo system. Due to these mods I am changing my alternator from 65A to 150A.

Will the larger alternator have an effect on fuel economy?

All the power it provides comes from the fuel you burn.
If you draw more power, it'll use a bit more fuel - an internal combustion engine is not a very efficient generator.

Did you see any benefit from the electric power steering ?

Im still waiting for some hefty wire to be delivered. Im also waiting for some ARP head studs as Ive just done my head gasket and installed a better flowing turbo and inlet manifold. I ran it with standard head bolts and lifted the head off the block...too much boost! Apparently these head studs do save fuel. I personally don't see how but so many people have them and swear they do. I want power from my van when I want it but mostly economy as i cruise off boost most of the time.
It will be a job to tell what MPG it is doing now as I have also messed about with the speedo and the needle isnt quite in the same place as it was. I think I will have to install a cigarette lighter socket and run sat nav from now on so I can monitor it properly.

My van didnt have power steering to start with so I'm not doing this for economy btw...its just too heavy on the steering for me TBH

It won't change your mileage.

it will recharge your battery a bit quicker when you start your car or use power steering, but that is about it.