djerratic

I wanted to know if it is not a good idea to switch to synthetic after 80k of dino oil. I just got the car with no leaks and oil loss but do not know the history of oil used.

I've read mixed answers on it leaking, and cleaning out the sludge and others have no problem at all. After it cleans out the sludge, ive also heard that it will burn some oil for a while and then stabalize or swell the seals once the entire process of synthetic has flushed out the old dino oil.

Can someone shed some light on the switch? I'd like to hear some switching over stories, good or bad as well.

negcamber

My only personal experience with switching from dino to synth on a car of that mileage left me with a motor that leaked like a sieve. I'll never do it again.

slipstream444

Short answer - you should have absolutely no problem as long as you switch to a high quality synthetic oil. There have been a number of folks that have had issues with off the charts consumption when switching to standard Mobil One - but a lot of AP1s have consumption issues, especially with standard Mobil 1.
The synthetic oils that I recommend are as following (in order): Amsoil ATM 10W30, Redline 10W30 (or 5W30) - number 2 because of high price, Mobil 1 EP 10W30, Castrol Syntec (German version) 0W30.

Synthetic oils I would never recommend: standard Mobil 1, Royal Purple, generic brand or store brand synthetic oils.

The only way a car will leak after a change from dino to synthetic is if the seals are dried out and you have sludge and gunk preventing leakage. This was common in the 70s and 80s but is almost unheard of in modern cars due to the fact many dino oils use many of the same synthetic additives that are used in synthetic oils - therefore, you don't have sludge and gunk build up (not nearly as much) and then have an active synthetic additive package clean an engine out, resulting in leaks. Additionally, the seals used in modern cars are not nearly as prone to drying out as in older cars.

djerratic

Thanks for all that info slipstream.

I will try out Amsoil ATM. I am a bit on the cautious side, because of what so many AP1 owners saying they are burning more oil after switching over to Mobil-1. I hope that it will be fine with Amsoil. I am planning to put the oil in, drive it for X amount of miles to flush out the dino oil, and refill etc. but what is X?

Negcamber, what synthetic oil did you switch to? And did you switch back to dino without leaks?

mlc

Check out the oil journals here https://www.s2ki.com/forums/index.php?act=S...0#entry12038273. A lot of good info.

I went with Maxlife. It is a blend. Check out the write up.

If you ask this question here you are going to get A LOT of opinions for sure.

Kevin

driftintherain

i use to use mobil1 and i was burning oil, but after i switch over to Amsoil i never burn oil

ahrmike

just run the full synth whatever you choose..for a shorter drain interval so you can get all the dyno out..then go with full synth, whatever drain interval you want to do.

kind of like chem class.

->wash out beaker with water.
now water is contaminating whatever I want to analyze
->wash out beaker with material of interest
rinse, repeatx3
->now its basically 99.999% material of interest, very small amount of water contamination. (depends on the size of beaker,blah blah but general idea is there...one flush is damn good already.)

2007 Zx-10

with 80k I would just keep running a good dino oil

negcamber

It was a car from the late 70s that I switched to synthetic Amsoil in the late 80s.

Switching back to dino oil didn't help. I ended up doing a rebuild and replacing the seals.

gospeedgo1

you forgot to add motul to that list. i switched my CRX to amsoil a few months ago. i did use the engine flush prior to changing the oil. i dont have any change in leaking. i do have a slight drip from time to time from my oil pan, but that was present when i used castrol gtx. my CRX has over 200K miles. it may leak, it may not. like said by others, use quality oil.