Hello everyone. My name is Shelby. I'm a 17 year-old male, and I will begin maintaining a few extra cars. I've enrolled in an advanced automotive class at school, so I have plenty of time to work on cars. The car I'm concerned with the most (right now) is my mother's 1990 Toyota 4Runner 3VZ-E (3.0L V6, 5spd manual, 4wd). It has about 154k on the clock, and it has been neglected for years. Other than a timing belt and an oil change in the past few months, there has been zero maintenance performed. We both love the truck, and I'd hate to see it break down. It seems pretty bulletproof, as the only signs of wear are an erratic idle and a slight oil leak. I know I'll be doing a lot of tune-up work (plugs, wires, cap, rotor, fuel filter, air filter, etc...) but I'm here to make sure I'm putting good fluids in to it. Engine Oil - I think I'm going to run two Auto-Rx treatments using Napa oil and Napa Gold filters (BTW, I get a hefty discount on Napa products through the school's automotive program. I'm not sure if this only applies to Napa-brand products, though). After this, I'm not sure whether to keep using a cheap dino (Chevron, Shell, etc...) with a 3k OCI, or use a more expensive synthetic (Amsoil, Mobil 1 EP) and shoot for a much longer OCI. So, what kind of oil would net me a long OCI with Napa Gold filters? I know that analyzing the oil is the only sure way to tell, but if you can give me a starting point, I'd appreciate it. Also, the manual doesn't specify a weight for the oil, so I need recommendations. I have 5w-30 in it right now, and it feels fine. It gets kind of cold here in Nevada, but not utterly cold. I'm thinking a 5w-30 in the winter and 10w-30 or 10w-40 in the summer. Coolant - I have a bottle of Zerex G05, and I hear that it's pretty good stuff, so no real questions here. Brake/Clutch Fluids - Manual recommends DOT3, so I think any name brand DOT3/4 fluid will suffice. MT/Transfer Case - Looks like they both want 75w-90 GL-5 gear oil. I planned on using Auto-Rx in the transmission. What would be a good host oil for this? Is Auto-Rx needed in the t-case? Again, I'm not sure if I should go with less expensive dino oils or high dollar synthetics (from Specialty Formulations). I could use dino recommendations. Differentials - Looks like 75w-90 hypoid gear oil. I bet Specialty Formulations has something, but should I look at a dino due to the vehicle's age? Recommendations? In a nutshell, I'm unsure if I should use expensive synthetics in this old truck, and, if not, what dino oils are of good quality? Am I headed in the right direction? Thank you for your time, and any and all advice is appreciated.