My brother in law bought a 90 model new. It’s got 180,000 on it now. We serviced the truck about three years ago and we installed a street 90 fitting with the plug installed up. It allows you to install about a 1/2 quart or more fluid. I think it uses Mobil one oil. He’s had no problem since new. The nv4500 has fifth gear problems but they have a fix for that too.