5w20 or 5w30

I've heard conflicting stories on what the best weight oil to run (Mobil 1 of course).
5.5 qts?

 

i use 5w30 but thats mainly because of the manual recommendation and from people on here. i'd like to hear more about this though if i should be using 20 instead. I run 5.5 qts and Penziol Platnum (full synthetic)

 

Its says the weight on the oil filler cap. Its 5w30. I also use Mobil 1

 

you have the v6 or the 4banger?

 

I switched from 10W/30 Castro GTX to 5W/30 Castrol SYNTEC just because I got 113K on '97.

 

V6 uses 5w-30 API SM. 4cyl uses 5w-20 API SM. You could probably get away with using the thinner oil as long as you don't tow and understand if you throw a rod toyota may not cover it. The only advantage would be a slight, I mean slight % of MPG gain. Be fun to try for a few tanks in the cty and hwy. just for MPG sake. Be a great project for a magazine to do. I run 5w-30 Quaker State Dino $10.50/5qts, or Mobil Clean 5k $11/5qts with a Motorcraft FL400S filter. That filter's design is first class compare to others. Both oils I listed are great, and will make the engine outlast the truck.

 

+1. I'll just add that you can run 0w30 synthetic in the v6, but it usually costs more and the only benefit is better start up protection on very cold mornings. Something to look into, but you will be fine with 5w30 synthetic. The 2.7 owners like myself can run 0w20 or 5w20. I've been running 5w20 Mobile 1 with a K&N oil filter and I change it every 6 months.