…or the age-old child argument:
Which are better, dogs or cats?
As the old saying goes, “You pays your money, and you makes your choice”. 
My choice is to use the oil grade/viscosity/specification that the vehicle mfr mentions in the Owner’s Manual. Others may differ, as is their choice.
That’s what I do for all of my vehicles
they all get Mobil 1 and get oil and filter changes at 5K intervals . . . even though that is technically too soon for some of them. It’s an easy number to remember, and it’s better than rolling the dice :
… an easy number- yes this is exactly why I do it at 5k - easy to remember w/o any written notes. Besides color of the oil - that really is not scientific but … going to a lab is not easy - you need to stick a stamp.
Yes, I just bought a Buick and I’m going to do my best to beat that but it’ll be quite a challenge in Northern Michigan.
Not so hard driving 3-4000 miles a month, even in Minnesota.
Ok, I’ll let you know in about 515,000 miles. 
.
I bet your 515k Buick was a low rpm pushrod, non turbo fairly large displacement, low reving specimen. Compare that to any 2020 Buick motor. 500k miles on new 2020 car? I would bet no. Best part is we probably won’t be around in 15 yrs.
You may want to see this video I ran across today.
This is the final test of 16 different synthetic oils and how all of them ranked. It includes Mobil 1, Supertech, Costco Synthetic, Royal Purple and others.
I saw your video
So what . . . ?!
I’m not changing my position on anything
And I won’t change my buying habits, either, in regards to engine oil
Where’s Doc the petroleum engineer? Kinda reminded me of that old Slick 50 demonstration with no oil in the crankcase (You know with the water pouring over it when cooling is one of the functions of oil). Not a very good welding job on that friction tester-looked like something I’d do.
I quit using Penz years ago and not likely to change again anyway. Like I said 520,000 miles on Mobil dino kinda figured it was ok regardless of what happens when you heat it up to 400 degrees. (3800, V6, 2000 rpm at 70 mph) But gee that’s not the only one. Olds at 240K, another Buick at 120K, another Riv at 350K, another Olds at 200K, some others up to 70K, lawn mowers etc. So hey, gonna take more than a youtube for me. I don’t race anything though so really doesn’t matter. I just don’t know how those tests relate to what’s happening in my engines.
Around here several auto parts stores carry it.
Wifes 87 and 96 Accords both went past 300k miles using nothing but conventional motor oil (usually Castrol GTX). No engine problems what-so-ever. We gave the 96 Accord to our Niece when she started college. She sold it when she graduated and it around 400k miles…and it started to burn a little oil.
My 90 and 98 Pathfinders both wen well past 300k miles using Mobil-1. The 98 started to burn a little oil after 400k miles.
So how many vehicles have you kept past 500k miles…Because if Amsoil is so much better you should easily reach 500k miles right???
Newer cars tends to use more plastic even in the engine, oil tank, intake etc.
Should we choose an oil that keeps the engine temp low or rather go to EV!
If you’re using the correct oil you’ll have no significant impact on oil temperature by changing to a different correct oil.
Correct me if I am wrong - it looks like the order is - around 8mins in the video above from @keith - it looks like Penz Ultra Platinum is a great alternative to M1:
AMS Signature series
Redline
Penz Ultra Platinum
…
Kendall
…
Valvoline Full Syn
Castrol
…
Royal
Amazon
Mobil1 (even Amazon beats M1, the darling of the industry - clever market penetration by ExxonMobil)
…
Motul
…
Lucas
Since I have no trust in that ‘test’ (no idea how accurate, repeatable, or representative of actual use the results are), I have no trust in the results.
Can you switch oil - say M1, then Penz Ultra Platinum, M1, M1, Penz Ultra Platinum…?
Because Penz Ultra Platinum is so close to AMS Signature?
Lastly, Tesla removed the middle man, dealership and sells directly. AMS oil seems to do the same too so they can innovate while keeping the prices low? Am I missing something here?
I see the oil discussion has generated 56 posts. True to form, oil discussions always generate a lot of posts.
Bob is the Oil Guy started as a small, simple forum to discuss oil. It has grown to a massive site with many, many active posters.
Why does this happen? I’d guess it is because it is the one job even the most limited car DIYer does (or did) on a regular basis. Our preferences are based on our experience with (usually) very limited knowledge of how oil is formulated, what those formulations mean and how it actually works.
We need a retired oil guy on this site!
I can’t argue against getting 400,000 miles using Valvoline dino oil - I won’t use that brand of oil (my bias) or 400K using Mobil 1. Both worked, right? Some believe the marketing information - some hype, some correct, some meaningless words. Some point to the science. Some buy solely on price - high or low!
It is the never-ending discussion…
I can tell that I had a 1987 Acura Integra - I was naive that I took it from Denver to Nevada and Arizona at around 100k mileage. I had 4 adults, and their bags for this week long trip. AC was turned on. The car is 1.6lit auto.
I slowly realized that the trip aged the car. There was minor engine oil seepage from around the head gasket. I switched to Volvoline High mileage and it seems to have helped/fixed the issue. I kept the car till 175k and/or another 20yrs. The buyer still drives the car.
The point being choice of oil does makes a huge difference. I never had to repair the engine or took it apart. It remained stock during my ownership.
Keep the prices low? Their oil is almost double what synthetic oil prices are at Walmart.
You can switch back an forth between any oil as long as it meets the API (or higher) and viscosity recommended for the vehicle.
Amsoil may be the best oil ever made. But so what? Any good oil will keep good designed and built vehicle well past 300k miles. From my personal experience - I’d say far less then 1% of us keep vehicles that long. Not even close. So what is Amsoil giving you?