I've been doing lots of reading and comparing of synthetic oil performances.
Yes, Amsoil seems to be the best, for their top of the line version, but it's way to expensive and if you're not tacking your car to the track and revving the crap out of it, you're wasting your hard earned $$$
For every day drivers who just gear down to 3rd on off and on ramps and revver up and normal driving, All synthetic brand names will do just fine, including the Big Red brand in Pickering..
That said, if you agree the Amsoil Signature is not necessary, their O.E. version has very very similar to Mobil 1, Vavoline, Pennzoil, Castrol, etc.. Some of these (upper version of all these name brands, not their base synthetic options) have bit better performance result #'s for TBN, TEOST, 4 Ball wear test, but very close, so basically, buy what's on sale, and you're all good.
From the Above, the Pennzoil has overall better numbers form a 5 category test I've seen and tallied their total scores and tallied their total score for 3/5 categories (the wear related ones only), etc. and found that Pennzoil and Vavoline were 2-3 place, Castrol titanium 4th, after Amsoil Signature at # 1.
Mobil 1 ext. perf. version, I found to be good too, but it doesn't seem to be all the hype. Its higher version will likely be a bit better and closer to Pennzoil Ultra and Vavoline Synpower.. I found Royal Purple had a higher score than this Mobil version used. NOT Saying Mobil is not good oil, it is, just saying it's not really better than the other good brands.
Mobil 1 and Castrol 4 ball wear test was very much lower score than their counter parts, which means it doesn't protect against wear as good. and Mobil 1 TEOST Test (oxidation and deposit-forming tendencies of engine oils) was also much lower as well. So, it's not my first choice.
Mobil 1 is 50% off at crappy tire right, pretty much all their models, so not a bad choice to grab the Ext. Perf. one, if are o.k. with just average performance and will change your oil every 6-7K kms max... and you don't drive your car hard at all.. why not save.
but Not their 3000 formula D1, cause it's not SN PLus rated, for helping with LSPI).this version is not good for gdi engines.
But for this same price as, I'd go with the Amsoil O.E. oil options. it's about the same as this current sale price, if a member or know an amsoil member to get you oil. or the other brands mentioned above, when they go on sale.
Personally, I'm leaning towards Amsoil O.E. (not the highest scores compared to Pennzoil or Vavoline in some categories, but close enough), or the Pennzoil, if I can find on sale or if their head office has member deals, etc.
And I do like the performance or our local Big Red oil brand in Pickering, but their Noak score (related to % of oil that burns away) is a bit worse than most of these, so better chance of needing to top up, if run it past 6k kms....of which I will report back on, cause I have Big Red in their now and almost 6K kms on that oil... I'll report if any was gone or still 100% full when I take it in for next oil change, likely next week.
1) Amsoil Signature
2) Pennzoil Ultra/VAvoline (super close but chose Pennzoil cause vavoline noak test was worse and may need top up) otherwise, Vavoline being 2nd is a wee bit better on the 3 wear/deposit related tests.
3) Castrol/Royal purple..
4) I'd put the Amsoil O.E. just after and in general comparable.
5) Big Red at similar level or just bit lower but very close and if better price, again, worth considering if not driving hard and plan to change oil on the sooner than later of the kms side of things.
There's a lot more type of test involved, of which are not mentioned in here, that I have seen and I get dizzy thinking about them.
Basically, any brand will do, since even Conventional oil is approved for this engine. and if you drive normal, buy whatever is on sale.
If drive hard, then buy what's better to protect your engine.
If drive crazy on the track every weekend, get Amsoil Signature, or the Pennzoil/Vavoline and save a few bucks.