BEST? Best is a relative term. The only best that we should be concerned with is that synthetic oil is BETTER than petrolium based oil, period.
Unfortunatly this is not entirely true. I have been in the automotive bussiness for over 17 years and yes ...years ago sythetic was proven to be better.However nowadays synthetic isn't all what it was compared to the petrol based oils.
nowadays petrolbased oils used in normal cars (not racecars) are much more tolerable against heat, cold etc.
You can ask your self ....BUT they use it in race cars ?...yeah...they sure do....but do you rebuild your engine every week ?...i thought not, see racecar motor run on an tolerance, if the race is 500 miles then they prep the motor to be able to run the 500 miles, if tey would all of an sudden double the lentgth of an race then you would see alot of motors getting ruined.
see racecars are devolped to run maybe 1000 miles or less, but normal car engine can run in excess of 200K miles easy....an race car aslo devolps ALOT more heat then an normal engine does and thus the oil has it alot worse then the normal motor will ever have it even in it's most extreme condition.
If you take care of your motor and you change the oils on the recommended times then you can just use normal petrol based oils.
my explorer has now 281K miles on it and it's still running ...though the piston rings are wearing out now , but further then that it's running liek the sun, and it has never seen an bottle of synthetic....just keep up with your motor en you can enjoy it along time.
people get too much into the oil thing, you can't compare race-cars with normal engines just because they are too much different from eachother....they are build different, they are used different....or do you run full throttle 3 hours at a time ?....i didn't think so.
this is just my 2cts on this whole sythetic/petrol based oils contraverse...