yeah i agree that modern hc oils have almost no drawbacks compared to pao oils. Maybe in small extreme cases.
I am no blender but from what i can understand PAO based oils etc.. are also more difficult to blend the additives.
Also a pure PAO oil is in no way beneficial that a good additve blended HC oil.
In germany where liqui moly comes from it is not allowed to sell hc oil with branding fully synthetic on the canister.
The higher you go from groups I through IV the less solubility the base oil has with respect to additives and the less effective it is as a carrier. So other bases are used to provide that function. Both AN's and POE are often used in PAO-based formulas to improve seal compatibility (PAO has a "drying" effect on seals and will shrink them, so there's a formulation balancing act performed here to prevent that from occurring).
Group III bases also have poor solubility, though it is better than PAO, but they lack the seal harshness problem so are often (not always) blended with Group II for better solubility vs more expensive options like AN's and Esters (POE).
Group III oils are significantly cheaper to blend based on the above, so it's not surprising that they are so popular. Since they can approach PAO-type performance in many respects, they are an obvious choice to increase profit margins and not have to deal with the delicate and expensive balancing act inherent with blending a PAO-based lube.
I agree with you in prices , but regarding HC oil , as far as I know that HC oil or group III base stock is extremely high refined oil with unique uniform structure that give the engine the almost the same protection and performance as PAO base stoc; and it can be considered synthetic as well , watch this video
I don't believe that's accurate (the uniform structure angle). HC oils are simply more severely refined than Group II and Group II+ oils, the act of hydrocracking further reduces the wax content and increases the purity but PAO is actually constructed from, IIRC, ethylene building blocks to produce a completely man-made hydrocarbon, which is why it is completely uniform in structure.
The primary advantages of PAO are:
- Improved oxidation resistance (beneficial for extended drains which is why the AMSOIL SS products are PAO-based)
- Unmatched cold temperature performance (PAO contains no wax so doesn't require dosing with PPD's to achieve its low temperature performance/pass testing)
All that said, a PAO-based lube with the same approvals as an HC product likely provides no discernible benefits unless you are routinely starting your engine when it is -40C or have a particularly demanding application for extended drains or highly prone to oxidation.