'06 Radiator

[Constant Mesh]

'06 Radiator Capacity (including all coolant routes) = 2.75 quarts

'04 FJR = 3.49 quarts

'04 has 27% more coolant.

'06 Coolant Reservoir (up to the max level) = 0.26 quarts

'04 = 0.26 quarts

With no air flow through the radiator (waiting at a traffic light, etc.) does the '06 coolant temperature rise faster than the earlier models?

 

[bmwhd]

Not sure since I've only ever had an '06 but I can tell you it comes up to normal op temp (4 bars out of 10) in about 60 seconds from a cold start.

 

[flyinlow]

They are totally different radiators, one of the fixes to beat the heat.

My question is: Why does this matter and why are you asking about it?

 

[Constant Mesh]

Just wondered with less coolant if the temperature would change more rapidly if there was no air flowing through the radiator. Probably does. As mentioned above, this would also help it come up to temperature quicker from a cold start. May be one reason why they added a second cooling fan. The coolant volume in the new radiator must be almost 3/4 quart less than the earlier model. The radiator's surface area appears larger so it's probably quite thin front-to-back.

Well they saved a little weight with less coolant. Probably offset by the second fan.

Many of the new BMW engine designs have the water pump located at the top of the engine instead of down low like the FJR. This could be a weight saving measure since the coolant hoses are shorter with correspondingly less coolant needed.