Why do people say that once you use synthetic in a car you should go back to natural??? I would like a technical explaination.. and would it kill me to use synthetic blend after my car has had full syn. in it?

 

Hmmm, I have heard some similar things also. Some autoX guides online say switch to synthetic oil, yet I have had a mechanic say don't switch to synthetic if you have an older engine (my 92 KA has 166k on it). He said something about the synthetic oil breaking up built up oil in the engine and causing your engine to burn it? He said use Castrol GTX High mileage. Anybody have any insite on switching to synthetic oil?

 

it will make leaks worse if you have leaks (upgrading)

i went from full synthetic to 50/50 synth blend. I have slightly worse leaks now.

 

there is a big difference between the two oils. ill start w/ the reg. oil first.
the reg. oil comes from crude oil. but by the time the oil reaches us, the crud oils been boiled or watever to make the different grades(0-20 20-50 vasalene). they also added different agents in the oil so its just a little better for our cars. the reg. oil is wax based, that is why people hate it so much. even though the wax is there to keep our motors clean, the wax tends to stick to everything and cause sludge and varnish all your ****. Wax will also break down. thats y 3k mi OR 6 months. Oh and even though the wax cleans your motor, it duzn't clean out sludge varnish and all that crap, its basically limited to dust and dirt.

Racing oils do not contain WAX, that is why they're good for a race. Don't go to autobacs and buy urself a race oili thinking ur car is going to run fine for the next 3k miles.

synthetic oil is man made. the molecular structure is completely different from reg. oil. in reg. oil you'll find WAX-WAX and OIL-OIL
while in synthetic, its just oil-cleaning agent. synthetic contains NO WAX. synthetic has a lot of different cleaning agents too. Basically the synthetic cleans up sludge and varish, and it duzn't produce and sludge or varnish cuz it contain any wax. THIS IS WHY YOUR CAR WILL LEAK. the Reason why people can go up to 5-6k miles on synthetic is because the oil duzn't break down. (break down- basically oil seperates into water and gunk) um....Mobil one is the best out of the Big companies, Not including royal purple. Some company just rebottles mobil one and sells for more.
theres alot more sheit i know but i need some time to remember. i worked at easy lube and i have to know my **** so i can sell it. top seller baby~ yea...

and if ur car is leaking. use the blends. blends have another additive that will help stop leaks i forgot if the full synthtetics have it too. But go w/ the blend and go a thicker oil or just rebuild and replace all ur gaskets.

 

OH.....ALL synthetic oils are FULLY compatable w/ reg. oil. you can MIX half SYn and half REG. The ONLY thing you have to KEEP the same is the Grade. 0-30 5-30 **** like that. and it even says it on the BOTTLes, so dont worry.
so u can switch back constantly

if u want more tech. crap then i might tell you...but i g2g take a crap right now

 

So what about my 140k mile 89' 240. I shouldnt switch to Mobil 1 synthetic. I should just go with the high milage stuff right?

 

everything that he said is true EXCEPT mixing.

NEVER MIX SYN. WITH NON SYN.

Please show me a bottle that says that! I was told DIRECTLY by a mobil one rep NOT TO MIX syn. with non-syn.

 

dont switch to syn. at 140. that will just leave puddles of expensive oil on your driveway.

 

Thanks for all the info. My engine doesn't smoke or leak but since it is at 166k I am going to put Maxlife oil in at the next change.