I'm considering V4, 5 and 6 STI's. What are the differences between the 3 and what are the going rates for these in stock form.

I've noticed a few V4s at 3k, but is a 6 worth the extra money?

 

One very big point is you cannot remap a v4 car so you would need an aftermarket ecu.

 

The 5 and 6 are very similar to each other and share pretty much all the same parts, the biggest difference between these 2 are that on the 5 you dont need to depress the clutch to start the car, on the 6 you do.
The 5&6 run the phase 2 engines (they have the coil pack offset to the right on the inlet manifold when looking into the engine), the version 4 runs a phase 1.5 engine, the coil pack is central on the inlet manifold.
Gearboxes on the 5&6 are also deemed to be stronger, these run the ty754's, the version 4 will run a ty752.
And as TTPJ has said, you cannot map the v4 ecu, you can with the 5&6.

Tony

 

Howcome the V4 ecu cant be mapped, is it scrambled or something like the ecu's on the legacy gtb's?

How much does an aftermarket ecu cost? Can't you just fit a sti5/6 ecu?