Originally Posted by
Uwiikz
DO NOT, and I repeat DO NOT use WD-40 as ARO, MMO is great but expensive, Mobil 1 Full synthetic 10w-30 engine oil would be THE VERY BEST and CHEAPEST ARO you can get, 1 quart will last you a lifetime and since it is fully synthetic, means no dino fat on it, it will never harm your plug, o rings or any silicone inside for that matter...
Try Mobil 1 full syn on your car and you'll quickly realize why it's the best oil out there.
Hate to tell you, but Mobile 1 is not a 'true' full synthetic. Hasn't been for a while; switch was done to keep their costs down. It's not a Group IV like Amsoil or Group V like Redline. Mobile 1 is a hydrocracked oil + some combination of PAO + POE and/or AN, etc. In most countries Group III can be marketed/regarded as a synthetic.
Not that it's a bad thing. Groupings are a bit dated anyway - each has their benefits and disadvantages. Generally the 'best' is some combination of blends, though it all depends on what you are looking for in an oil.
With regards to M1, 0w-40 and 0w-30 are the closest two to a PAO base.