Engine oil Shell or PENNZOIL

Pennzoil ultra platinum. It is what they put in it from factory and it is one of the best oils around next to amsoil for a lot less money.

I've used T6 in my MK4 BEW for 5 years now. Regular changes, no issues at all, and at 1/3, the cost of 'suggested' brand.

I know this is old, so you’ve probably already made your decision, but I use Pennzoil Platinum. It’s a great oil as well and tends to be slightly cheaper than the Amsoil.

Personally I rock she’ll rotella 15w40 in the summer and 5w40 in the winter to aid in cold starting. Seems to work pretty good

That's what I run. It supposedly runs lighter than the specified 40. It's LL-01 approved. I change it every 8000km/5000miles.

The best performing oil for cold starts is probably Pennzoil platinum full synthetic if your particular prius uses 0w-20. It is made from syn gas, and is particularly thin.

For comparison, i got 6,000 miles out of Pennzoil platinum vs royal purple, with which i would get 5,000 miles prior to the oil changing color and about a 1 to 2 percent dip in fuel economy. Regardless of the wear additives, Pennzoil platinum lasts longer, again likely due to the cold start performance and the way the hybrid drivetrain works.

Haven’t heard anything like that about Mobil 1, but I personally use Pennzoil Ultra Platinum 5w30. It’s performed spectacularly for me.

Shell helix has been fine for me

Penzoil Ultra Platinum will be on a entire different level. Stuff is amazing.

Penzoil platinum held up nicely. A hair thinner and less active additive than Valvoline but wear looks great.