I plan on installing VDO voltmeter and oil temperature gauges soon on my '06 MC (non-S) via the OEM center console panel. I'm not wanting to use the VDO Cockpit gauges that are part of the OEM gauge kit, though; I want to use a different model range (Ocean Line White), so I'm essentially piecing the OEM kit together & wiring it myself.

However, I don't know what thread size to get for the oil temp sender, which screws into an oil-drain plug location on the side of the engine block (the OEM installation instructions are on MiniMania's web site). VDO gauges require VDO senders since the ohm range is different, so I can't use a T-fitting anywhere. Does anyone know what thread size I should get for that fitting?