What is the proper gauge wire do I need to use when replacing the oil temp wire up to the dash? Thanks.

Since it is just the variable resistance of the sender to ground, the wire carries very little current.
Stock Oil temp wiring id 0.5mm which is smaller than 20 gauge wire.

I would probably use 16 gauge wire because it is a little stronger and wil survive under the engine a little better.

Jim

I'll 2nd 16 - 20 gauge.

Thx