Zellanor

I have heard that synthetic oil should never have to be changed because it's synthetic, and that you should only have to change the filter? does this hold any truth? I'm running Castrol Synthetic 5-20 in my pony now, and I change the oil about every 6-7k. How often should you change out synthetic oil? Thanks

Perdi

Synthetic does break down, just not as fast. I'm still changing mine at 3000 (Mobile 1) but only cause the car is still under 10K miles.

6-7K is fine, and you could go more...Personally I wouldn't, at least not in 'my baby' but on a POS I've gone 20K with no problems.

NomadSteve

+1 - while synthetic lasts a lot longer and does not have as much volatile losses as dyno oil, you still need to get the wear particles out. I would also think that combustin gasses effect the life eventually making it less effective.

22kart22

Well my dad is an engineer at exxon mobil.
here it goes:
Synthetic is man-made whil patroleum oil is from natural crude.
I can really care less if you buy Mobil, and Im not trying to convince you to get it, but I am just gonna give you the facts...

Mobil One is fully synthetic and shows virtually no breakdown within 30 thousand miles.
Thats why Mobil extended is intended to be changed every 15,000 miles. All you have to do is change the oil filter and fill it to maintain oil level.

So I only use mobil one in everything because its pretty darn good.

cheers

howarmat

It does still break down, just not as quickly...you rfilter however is the weak spot...I would change everything around 5K just to be safe.

22kart22

exactly. My point exactly

GT Bob

I will be going to Mobil one as well. Used it in my Colorado and had the oil tested after 12K miles (keep in mind, I changed the filter every 3000 and topped off as needed, and didn't start the extended oil service until after the motor was well broken in), and was told that it was still protecting as well or better than most Mineral type oils do brand new. Itdoes break down, from heat and combustion gasses, but if you keep a clean filter in it, and top off as needed, I can see an easy service life of 10K miles out of it.

The filter truely is the weak spot... Don't buy some crappy Fram filter. they are junk. Spend the extra few dollars and get a quality filter (K&N and Delco's are pretty good) if you plan on going past 3K miles on the oil.

tncruiser

oil= 1.49
syn oil = 6.99
engine = 2700.00
use good oil change often save 2200 over engine life

owero01

I know a guy who only changed the filter for years using regular every 3K and topping it off. He kept the car for several years and over 150K miles. The filter is definitely the key.

ModernMuscle

from what ive heard, mobile one is not fully synthetic, even though it says it is.
I quit royal purple, do to some test results i have seen, and switched to amsoil 0-20 full syn, with k&n filters.
thats just my .02