Use 5w20. I do, and on occasion, 0w30. Most everyone here is going to recommend you use what the manufacturer recommends.

 

thanks for the quick reply i guess im just old school i have a built amc 360 in my cj7 and all i will run is 20 50 vr1, a bunch of my friends have dirt track modified race cars and again the same 20 50 vr1.

 

It's hard to divorce yourself from old school thinking. My first car, second car, third, 4th, 5th, and 6th.....all Castrol 20/50.

The rumor is that you could cause oil starvation to critical parts if you do not use the 5w20 wt. oil.

 

well im gonna go buy all the stuff for the oil change in the am is there any brand or type everyone goes with, i have heard not to switch to synthetics unless it was ran from start, cuz it will cause leaks at seals? idk?

 

Bunk.

You can switch to synthetic anytime you want between 3000 and 80,000. They come with a synthetic blend in them anyway. Ford's Motorcraft 5w20 syn. blend is cheap and it's good oil. You can use it. They also now have a fully synthetic 5w20.

I use Royal Purple, Amsoil, Leading Edge, Mobil 1, Redline....whatever is convenient to get or order....all synthetic.

But mostly Amsoil, then RP and Leading Edge.

 

Your stuck somewhere back in time. Back when synthetics where harsher and seals where weaker.

1998 Ford updated there seals to handle the harsher synthetics , since that time synthetics have come along way and are milder, more versatile.

You can use the oil anywhere nowadays, it's totally replaced Mercon transmission oil..

Engines run cooler , less friction and better mileage can be had, so why not take advantage of it.