Shell Rotella 15W-40 T5 Synthetic Blend

[KevAndAndi]

Bought this on Amazon by mistake. Meant to get regular, not synthetic blend. (There is also apparently a full-synthetic version “T6”.) Should I return it? I’ve read here that people often have oil leaks after switching to synthetic, but I’m not sure if that’s true with a synthetic blend.

[kilrwail]

I use Brad Penn/Penn Grade 20W 50 in both cars because of its high zinc and phosphorus concentrations. It's been a synthetic blend for quite a while. No problems whatsoever.

[DieselSpider]

It used to be in the past that Synthetics caused the seals to swell a bit more than Dinosaur oil so on changeover to synthetic some leaks would be cured however when switching back to non-synthetic the seals would shrink and then leak worse than before. I believe that they have resolved that to a degree since then however you may want to consider this as potentially being a long term commitment to staying at least with a blend.

[KevAndAndi]

Thanks, I ultimately decided to return it and go with the non-synthetic.