Review on Royal Purple Synchromax Manual Transmission Oils & Fluids by Joshua Talbot

I have a 2006 16 year old Ram 2500 with a 5.9 liter Cummins engine and a Mercedes G56 6 speed gearbox (224 .00 miles) and all that stuff. it worked great. It made a big difference when shifting and seemed to settle him down a bit. I used an extra 1 liter as recommended by many online. This is a mid-range lube that definitely beats its price. I live in Michigan and it was -10 degrees F last week and they have changed well even though it was cold. I couldn't be happier.