Best Synthetic Motor Oil?

[nomore55]

Amsoil is a fine Group IV product if you don't mind chasing after it.

M1 has been around for years and has earned an excellent reputation and is selected for the factory fill in many nicer cars.

There's no such thing as a universal "best" quart of oil.

[Scott]

You can't go wrong with Royal Purple, Amsoil, or Redline. All are %100 synthetic and are proven to work and even recover lost horsepower. Most advertised synthetic oils are actually NOT %100 synthetic.

Mobil1 is more readily available and is also quite good. It comes stock on the higher end cars like the Viper and Mercedes Benz. I use it on the Mercedes ML320 because it is the OEM oil for the recommended 10,000 mile interval. I do have to add a quart of oil once every 5,000 miles, but I think its just the car itself having problems as the whole pre-2005 M-class line is basically a lemon. It takes 8 quarts of Mobil1 to fill up every oil change plus the $30 MB filter, thank goodness it lasts for 10,000 miles.

I use Royal Purple on the Supra and I beat the hell out of that engine. I touch redline in lower gears and at least 135mph+ almost everytime I get on it, (on lonely higways of course). I also use it in stop and go traffic for a good part of the summer which is worse on an engine. No oil loss, and maintains good oil pressure at the right times. I do change oil every 2,000 miles though. The downside is that it is purple and is hard to see if it's clean or dirty. It costs $5.50 a quart.

Last, pick out a good filter. I always use OEM brand oil filters (Toyota is synthetic), or high quality aftermarket synthetics, and NEVER use Fram. Walmart's old oil filters were actually %100 synthetic and made by the same compnay as Mobil1 but sold for $2 each instead of $10. I don't think they still have the same ones now though. But that is what I used on the "regular" cars.

X2.