Engine oil Castrol or AMSOIL

My T/A 392 has seen 311°F. ????. I added a bigger oil cooler after that.

I was running 0w40 Amsoil Signature, no metal in the filter.

I'm a loyal Amsoil user. I usually change my oil every 5k miles. However, 3 oil changes ago, I started sending samples to Blackstone.

First Analysis: paraphrased, engine looks great

Second Analysis 5k miles later: Engine Looks great, Oil still has plenty of life

Third Analysis, another 5k miles later: everything looks great, try waiting 8k between oil changes.

I've been using 15w40 diesel motor oil in the AMC/Jeep flat tappet engines for nearly 20 years. Castrol makes a line called GTX Classic that's formulated for flat tappet engines as well

I just put Amsoil High Mileage, 0w20 in my 2012 Camry to see if it will benefit my engine with 221,000 on it. I switched from Mobil 1, which I used for years changing at 5K intervals, but had to keep topping off very often. The engine flush was excellent, the oil I drained only had 1500 miles on it and it came out looking like liquid coal! So a cleaning did take place, I'll see how it goes.

I use Castrol Magnatec A3/B4 10W-40 part synthetic. 3 years now and no problems.

5W-30 Castrol C4, never fails with my Clio. DPF is safe and sound, no soot, no weird smells.

5W40 Castrol Euro. I get less oil consumption than 5w-30 and it seems to run a bit more smoothly.

Castrol Edge 'Euro Car' 5W-40

Used to get a big white plume on cold starts but no more. Still burn a lot, but not as much

Best oil I've used

I ran Castrol 5W30 full synthetic in the engine.It burned a quart every 3500-4000.

Car has been at the stealership for three weeks. Same transmission TC seal leak. Bolts and seals also needed replacing. Car is 45 days old with 4K KM’s.