Im nearing the 70k mile mark and I was just curious if it was too late to switch over to synthetic oil?

 

it isn't too late, however the synthetic oil will cause any plugs that conventional oil pluged in the engine to become unpluged and leak oil....the synthetic will clean out the engine a bit......i say this late in the game it isn't worth switching......now if you had 7000 miles it would be ok....

 

i have 76000 miles on mine and i just changed to castrol syntec a few days ago. no problems yet.

 

how about 36K?

 

i'm not saying that it shouldn't be done i am saying that you will see a less of a benefit from changing it later than sooner!

 

Personally I would stick with non syn you can get something like
Trop-Artic for 1.47/qt that has 95% of the benefits of syn for way cheaper..
It is a group III oil (like castrol syntec) another good choice is the motorcraft oil
its also a group III oil. If you want syn I wouldnt bother with castrol syntec as its
sorta a "Fake" syn oil. I'd go with something like M1 or Pennzoil Platinum.

Currently I have 12 more qts of Pennzoil I scored for 1.89 after rebate.
Then I have 16 qts of Valvoline Maxlife Syn that I got for Free just had to pay tax
then full rebate.

Syn wont hurt anything though the worst it could do is clean out some deposits
and cause a slow leak.. It isnt actually causing the seal to leak but by cleaning it a leak may develop that was plugged by crap from regular oil.

If I may suggest anyone who wants to know more about oil that you could
possibly want to know.. visit bobistheoilguy.com
their forum link. There is more info that you would believe
about oil filters and different oils. Just make sure to be polite if you post
because it is VERY moderated and FAMILY orientated
http://theoildrop.server101.com/ubb/ultimatebb.php

 

how do you come up with castrol syntec is a fake synthetic?

 

The main advantage of syn oil is extending your OCI (oil change interval)
if you are going to change at 3-5000 miles its not really worth it unless
you are doing something severe like taxi.. or door to door delivery etc

 

i dont think that castrol syntec is a fake syntec.. but it is just part synthetic... which is better than none. but its not full synthetic oil. btw... i wouldnt switch this late

 

Syntec is A group III base oil basically hydrocracked super refined oil..
where everyone else's definition of syn is not refined oil.
so its "fake"
Why pay 5$ for syntec when you can get a similar product for less than 2$/qt

by contrast Amsoil, M1, pennzoil and others are group IV based syn PAO which
is more what people think of when you think syn.

Castrol basically used a loophole in how synethic oil is definied to call it syn..
their formula wouldnt be called syn if the definition of a syn was better defined.

 

I just use Motorcraft 10w30 in the winter, and 5w30 in the summer.....it is a synthetic blend.....that is what ford puts in it from the factory, so i will use it till the day the truck isn't mine........

 

ive been runnin synthetic in mine sence i hit 20,000 i have about 40,000 now

 

I switched around 50k. Curently 116k and the only oil leak i have is a small drip at the rear main(i think). Im gonna checkit out when i swap the trans.