I have been using Fram in my S10 for the Past 2 years. Fram in the Escort for the past year and Fram in the Datsun for the past 2 years also.

Never have had an issue. My oil lasts a little longer then is should most of the time, don't leak, don't brake, and my oil from the dipstick and when drained is clean (no particales or clumps of any kind.)

I would use STP because it is a few cents cheaper, but I love that Fram has the rough end there for much easier removal and installation, so that is why I get them. I have been thinking of trying a tough guard, but not sure if it is really worth it. They are like double the cost.