7mslider;1547802 said:
you can switch back and forth from conventional to synthetic as much as you please. i used to work at valvoline for about 5yrs. the additive package of a synthetic is the same as conventional, just more. the oils use the same base stock. even if you use a synthetic i personally still wouldn't extend the change intervals as the additives being the same will break down at the same rate. the advantage of a synthetic oil is it's lubricating propertys. the oil is made up of similar sized molicules so it lubricates better, and causes less wear on engine componants. to extend an oil change interval read the back of one of the extended interval oils and see all of the criteria you have to meet to do it. as far as weight, look in your owners manual and it has the different weights for different temps listed. i personally use a 20w50 since i hot lap my car at the drag strip. hope this has given you a little help
The base stock is not the same - synthetic oils (the true ones) use PAO or ester as base stock. Many on the market say "synthetic" but in reality use an extensively hydrocracked mineral oil.
The additives are similar, but are formulated for the base stock. Not necessarily more - take viscosity index improver for example - in a synthetic there is less due to the properties of the base stock. They do not break down at the same rate as a conventional oil. A synthetic oil will go 8K easy between change intervals, just change the filter at 4K. Using analysis, I've seen synthetic oils go 12-15K before the additives were depleted. Changing oil (including conventional) at the 3K point like the change shops say is simply dumping perfectly good oil and handing the shop you hard earned $$$ for nothing.
Concerning the 20W-50 - I've beat this one to death. If you think you are helping your motor using a oil that pumps like honey, then you are even more ignorant than your post makes you appear to be. Suggest you read the Motor Oil 101 link in my sig.
Given the info in this post is so off base it's not even funny, please do not post on this subject again.
Suprasonic19;1547944 said:
Wow. Thats some seriously good info. You just answered every question ive ever had about synthetic. I work at an auto shop and I get asked by customers often why synthetic is better and I have never had an answer. Now ill tell them that whole thing and they be like "Uh....what?". Haha.
Anyone that reads this would be very smart to simply ignore it. If you tell people what you just read, then you will be just a guilty of spreading myths/BS as our friend that was a janitor at Valvoline.