The 4.0L 1GRFE engine, identified by the 5th digit VIN U and configured for all models except the X Runner, is a versatile used engine choice. This engine offers steady performance with a naturally aspirated V6 layout and an electronic multi-port fuel injection system for efficient fuel handling. Its DOHC design with advanced timing provides smooth operation, making it suitable for various vehicle applications. Drivers looking for a dependable and powerful used engine will find this to be a robust and reliable choice.