For 2000 Focus Wagon First generation (MK1) Ford recommends to use: WSS-M2C913-A, WSS-M2C912-A, and WSS-M2C912-A1 engine oils. To select the right engine oil see the table below.
dot 4 normally has a 230 degree boiling point, 5.1 has the 260 degree, but i suspect there are certain other aspect of the fluid you have there which dont meet 5.1 specs & thus they called it 4+ :L. as for if its any good then only way to find out is to bang it in the car & see. Here you can find 2005 Ford Focus Sedan air conditioning compressor oil capacity. (MK1) C170 Platform. Ford Focus Sedan Second generation (MK2) model yearsFocus RS Mk1. Engine: Ford 2.0-litre Zetec engine 4-cylinder, 16 valve. Electronic Ford Engine Management Syetem. Garrett turbocharger. Catalytic convertor. Drive system: Front wheel drive with Quaife Automatic Torque Biasing Differential. Transmission: Uprated MTX-75 5-speed, unique gear ratios, AP racing clutch.
The coolant when cold should be between the min and max level.When at working temperature the coolant level can be at the maximum level due to expansion.If you are topping up to the max when cold maybe you are overfilling,just a thought.I've owned my MK1 for five years and haven't needed to do a top up.Maybe I m lucky. . 195 148 83 377 154 317 92 423