are the radiators from a us and the euro m3 the same or is the one from a euro m3 bigger?

The euro rad has a thicker core.

thanks, i already thought that

It's a triple core instead of a dual core. It also has the provisions to mount the oil cooler to the bottom, a US rad. does not.

FYI Euro rad. and S54 rad. are the same thing; S54 rad. is cheaper in most places.

It's a triple core instead of a dual core. It also has the provisions to mount the oil cooler to the bottom, a US rad. does not.

FYI Euro rad. and S54 rad. are the same thing; S54 rad. is cheaper in most places.
The Euro radiator is shorter to fit the oil cooler. The US radiator has the exact same end tanks, but the US core goes deeper and interferes with the placement of the oil cooler.

Also, the Z3 S54 radiator is the same, but the E46 S54 radiator is not. You want the Euro E36 M3 or 2001 Z3 M Roadster/Coupe radiator, part number 17 11 2 227 281.

The E46 M3 has different necks I believe, and a slicker way of connecting/disconnecting from the hoses that go to the engine. No more of the old fashion hose clamps in that newer system.

(no Euro content... yes, I know)

The Euro radiator is shorter to fit the oil cooler. The US radiator has the exact same end tanks, but the US core goes deeper and interferes with the placement of the oil cooler.

Also, the Z3 S54 radiator is the same, but the E46 S54 radiator is not. You want the Euro E36 M3 or 2001 Z3 M Roadster/Coupe radiator, part number 17 11 2 227 281.

Thanks James, you're right (big surprise). It's been so long I forgot to specify its the Z3 S54 radiator you want... I paid around $350 from bimmerworld for mine. I think the Euro E36 rad. costs $500-600 for the exact same thing iirc.

Alex, I just checked my E46 M3 and it has some sort of plastic elbow fittings with a trick type of connector, but still uses hoses & clamps to go from the motor to said fittings!

Alex, I just checked my E46 M3 and it has some sort of plastic elbow fittings with a trick type of connector, but still uses hoses & clamps to go from the motor to said fittings!

Right, I'm sure that the S54 thermostat housing was not re-designed from the S50B30 or S50B32, so it would use the old clamps there. They re-did the radiator ..... thus its connectors.