Angus where do you get that information from? I have never heard that Yokohama has enkei making their wheels. Even if true, and they are being made in the same factory, that certainly does not make these brands the "same wheel". The reason I said the RSII is better than then weds SA60M is because the sa60 is sort of an ignored wheel by weds. They come in very limited offsets, limited colors, and are heavier. Are they manufactured "better", I don't know. I don't know if the SA60 is flow formed.
Truth is within one brand the quality of wheels differ greatly. A Volk is a higher quality wheel than a Gram Lights, even though they are all made by volk. Even under the enkei brand you have very high quality forged wheels, and you have some pretty cheap cast wheels. I don't think anything coming out of an enkei factory or a Yokohama factory is going to be "poor" in quality, but I can't say that for all brands. It is best to compare model to model. I think saying the wheels are the same because they exit the same factory is like saying all Bridgestone tires or Michelin tires are the same. Or saying "Bridgestone is better than Dunlop".
It's all about marketing, if you look at the "good" Enkei wheels, they are the ones made in Japan - these are the ones I am referring to. BTW - none of them are really "forged" rather they use "M.A.T" ("most advanced technology").
If you look closely, you will see the labels inside the barrels of Adavn, Enkei, and Weds (only to name a few) are all the same, some even bear the name of the same inspectors etc.
There are only a few foundries in Japan making wheels - Enkei is one of the largest.
I assure you that if a difference exists in the Enkei Japan wheels it is due to the design and style of the wheels and not the manufacturer, within every brand there are stronger or lighter wheels, I was merely commenting on what I have heard many times - "Advan is better than Weds or Enkei is better than ..."
I see your point about products ranging in quality within one company, the difference is that with Rays, their wheels are all made in Japan in the same factories - Volk = are almost always forged wheels (with the exception of those that use cast centers) and while the Rays Gram Lights "brand" also has featured some forged 2pc. wheels (using the exact same barrels as the Volks and cast centers) they have mainly now become heavier cast wheels.
Rays also makes other people's wheels for them - Prodrive, RO_JA, etc.
The same cannot be said for Enkei, their Japan made wheels are mostly all the same high quality - with the exception of some 2pc wheels that were made in the past like Weds 2pc. , Blitz 2pc. , Racing Hart, original Stern just to name a few (on the old days - 80's LOL - there were scores of wheels made by Rays and Enkei, all labelled with other brand names) - most of their wheels now are 1pc. and use the same "M.A.T" process while their cheaper cast wheels are made in China.
It is not at all the same as comparing to tires because while tires use a different rubber compound to change the performance, I have found that the metallurgy of the wheels made by Enkei in Japan is not much different - as I said the design might produce a wheel that is lighter or stronger but the build quality (the process) and materials are the same - in fact a lot of the Enkei wheels are marked with the grade of aluminum used, I have seen the metal used in wheels from years of welding them myself and even making one wheel out of two sometimes (a Chinese Enkei cast wheel and a Japan Enkei wheel are completely different, and these are not what I am referring to)
