Hey guys, I always put 10w30 synthetic oil in my car, then one day I meet my friend's mechanic and he tells me that it is bad and makes tha car to run loudera nd bla bla bla, I laughed at him but the thing is my friend puts regular oil and we do the same maintanance and don't race and his car DOES run quiter. What can you tell me about that? And also he told me that it is BADDD to go back from synthetic to regular oil.... Thanks in advance!

 

lol maybe you have a hole in the exhuast or something? Everything I have read says synthetic is better. Lower coefficeint of friction so less friction and it holds a film better which means less wear on engine parts. It also degrades less with contamination/heat so it should last longer and make less gunk.

maybe you need an oil change or he just got one, newer oil works better. My car gets noticeably quieter when I change the oil.

i'm not sure if the advanced performance forum is the best spot for this thread?

 

Just replaced my oil with Castrol Synthetic. Have a 92 SE with 101,000 miles. But now it seems my engine sounds a lot louder. Thought maybe it was my filter, which is a Purolator Premium Plus. Any ideas?

 

Synthetic oil is thinner than regular oil, therefore it is going to be louder than dino oil. I wouldn't worry about it. If you mix oil you should change the oil out quicker on the first change and make sure you do the change on level ground. Sometimes the oils do not mix well together and bond together.

 

Some oil filters have no anti drain back valve. This results in noisy starts as the oil filter fills back up. Check to see if the Purolator has an anti drain back valve. Also some oils are just not compatible with some engines.
I would use some auto-rx and follow their instructions to clean up the engine. Then start over with a different oil. I just finished an auto-rx routine and have a fresh fill of 5-30 Red Line Synthetic.

 

Respectfully, NO! Synthetic oils are fluids just the same as the dino based oils. The thickness or thin-ness of an oil is just one of its physical properties, and is commonly measured in "Centistokes" (cSt). The SAE grades we're all used to, are defined in terms of ranges of thickness, not absolute values. I don't have my refs handy, but the 30 wt range includes oils that test from about 9.5 to 12.5 cSt, IIRC (if someone has the exact specs handy, please post 'em, but these #s are close). The popular Mobil-1 xW-30 oils mostly tend to the very low end of the 30 wt range, some being under 10 cSt (although with the inception of the EP line, a couple are now being produced at around 11 cSt). IMO, the "syn is thin" myth derives from the relative lightness of the widely available M1 products. Other synthetic products, such as Castrol's German-made 0w-30 Syntec product (this is the lone exception in the Syntec line; it's not a G-III hydrocracked syn) tests out at just under 12.5 cSt, so it's definitely not a "thiner" oil when compared to what most consumers use these days. In fact, it's almost a 40 wt when hot. And as an extreme example, look at Amsoil's straight SAE 60 synthetic racing oil -- would you say that's "thinner" than "regular" oil?

 

Champ, my apologies if it looks like I'm picking on you...not my intent. One more thought regarding mixing. While I'd agree that mixing is not generally a preferrable thing to do, at least nowadays, it's not nearly as problematic as it once was. And within product lines, it's generally no problem at all. Mobil, for example, will tell you if you ask, that it's perfectly OK to blend grades within their product lines. On the other hand, back in the early days of synthetics being used at the consumer level (early 70s) there were some scary problems. The most notable was that certain early di-ester based syns, when mixed with petro (dino) based products, would actually form a gooey solid substance -- not good at all for lubricating an engine. The early dangerous formulations are long gone from the market. The only maker I know of that offers a pure di-ester based oil is Neo, and even they indicate that it's OK to mix their products with others. So, while in most cases, the consumer is probably better off letting the engineer's formulations work as designed, versus mixing one with another, in the vast majority of cases, mixing will do no harm perhaps until the "soup" is pushed to and beyond it's limits. If you check the used oil analysis postings at BITOG, you'll see that the "mix masters" usually get perfectly good results, both from a wear metal and a fluid condition perspective.

 

Your info is way off. The 30 weight is 30 weight dino or syn. Much like what weighs more a pound of metal or a pound of feathers? A pound is a pound is a pound.