The Subaru engines ECU has a tach output. The Vanagon tach from 1986-1991 is not sensitive enough to pick up this signal so a solution must be found to drive the tachometer. Re-calibrated to read either 7,000 or 8,000 rpm to match your engine. This product can be installed in 1985-1991 Vanagon’s and works for all Subaru four cylinder engines. Sold exchange for your tach unit. Core must be received before we ship out the modified tach.