my response to his stupid Amsoil thread (i'm sorry but oil DOES NOT improve cold starts)
Ummm it does......
off topic to this post but you'll find that for example a 10w30 synthetic will pour roughly the same in 0 degrees or 20 degrees celcius. Perhaps 20w50 would be a better example.
Get a bottle of your favourite mineral/dino oil in 20w50. Now get a bottle of any real synthetic like Amsoil (PAO based) or Royal purple, Motul (ester based), Elf...etc etc. You'll quickly understand that synthetic pours almost the same in cold or hot ambient temperatures. So if you used 20w50 mineral oil in your engine on a cold winter day the oil will be thicker compared to a 20w50 synthetic. Get two bottles and pour them at the same time. I guarantee the synthetic bottle will empty faster in 0 degrees.
Synthetic DOES improve cold starts because the oil will not get thicker due to cold extreme weather. That is the whole purpose of multigrade oils in north american climates. Oil pours easier in the cold but retain a the viscosity of a thicker oil like 30, 40 or 50 weight when at operating temperatures. Synthetic multigrades just does a better job than multigrade mineral oil in the cold.
If you worked in a cold automotive shop like I do (winter months) you'll see this with your own eyes. It will take alot more effort to pump 20w50 out of a drum of oil in the winter than in the spring/summer/fall months.
If your talking about fuel enrichment on cold starts this is a totally different topic but if your talking about oil thickness, synthetic will help cranking speeds of a cold engine in the cold compared to dino oil.
These are facts that you can experiment yourself. Many mechanics that have full knoweledge of sythetic oils will also agree.
