I have thought about this. Here are my conclusions.
Today's "SN" or, heck, even SM and SL oils have 0W and 5W grades.
0W is better all the time, even at the Equator in July. HOWEVER. That said, 0W is MUCH less readily available than a 5W, and te majority of the time and for most engines, 5W is fine, just fine. Even for expensive cars, a 5W oil is perfectly fine for most cars.
The stigma over 0W is that it is a better oil, and this is largely due to the FACT that 0W tends to use better "base stocks" to achieve its 0W flow rating. Please note that there is, and liey cant be or there would have been one by now, a 0W conventional. Kendall makes a 0W semi-syn, so i hear. If i could find it, id check it out.
It comes down to PRICE. You can get 5W-20 Supertech for ~$12 at Walmart, and its a fine oil. 5W, yes, but nice flowing and a great oil.The 0W advantage is that it is a
better oil and for a car that likes its oil in the 30-weight range then Redline is a good choice as its 0W-20 is a light 30, and for a car that likes its oil in the 40 or dare i say it 50-weight range than GC is a good choice because it is a thick-30; note the price difference of these 0W oils vs the Supertech, 5 quarts costs what ONE quart does.
I dont know a lot about Mobil 1 Advanced Fuel Economy 0W-20 or 0w30 but why get that when you can get Honda Idemitsu Oil from Honda dealer, for your thin oil experimesnts.
Ive tried a lot of oils and i notice the Supertech usually does fine, i have noticed more engine drag with other brands of a same weight and it actually runs very well. This in a conventional oil, different cars perhaps like differnet oils an there will always be those that fear putting a synthetic in their car, likely because of what happened when they did in a previous car that has an "Actual results in the driveway" vs "what the Internet says isnt supposed to happen, or is impossible"
Hope this helps.
