Synthetic Oil question.

[chevytrucks92]

I'm planning on running synthetic oil in my new truck (Mobile 1 Truck & SUV), and am wondering when I should change it over to synthetic. I've always heard you're supposed to break in a new engine on conventional oil.

My owners manual said everything should be seated in and broke in properally after 500 miles (got a big thing where it says not to drive over 55 mph for the first 500 miles, etc. etc. yadda yadda).

So anyways, for you guys that use synthetic oil, or know something about it, do you reckon it'd be ok for me to start using it at my first oil change (which will be at or before the 3000 mile mark) or should I change it one time with conventional oil and then switch to synthetic at the next oil change (which again, will be at or before every 3000 miles, synthetic or not).

[MaXXuS]

From what I understand, you are supposed to break it then keep going on the same oil until you hit your first oil change. Then you can switch, but I was told by this girl that i know that works at subaru (in service) once you switch the synthentic you have to keep using it always. It may be different for trucks?

::EDIT::
I know because I asked her when i got my first oil change and she said just wait until you hit 30,000?(i think) and then switch over becuase they supposedly use a synthetic blend, so you might want to check with your dealers service department. I would talk to one of the techs because the service people can bullshit you to get money outta you.

[Mr. Luos]

Switching at about 1500 on mine.

[Musashi3000GT]

Go to 3000 miles on regular dyno oil, then after 3000 switch to synthetic.

[Chiquae07]

do u guys think its too late to switch to synthetic if im already over 100k miles? i was actually thinking of doing the change, but i diddnt know if i still could.

[MaXXuS]

Originally Posted by Chiquae07

do u guys think its too late to switch to synthetic if im already over 100k miles? i was actually thinking of doing the change, but i diddnt know if i still could.

It might be good for the motor, but i read something about seals going bad and the oil will leak after a lot of mileage.

[rice(er)]

Originally Posted by Chiquae07

do u guys think its too late to switch to synthetic if im already over 100k miles? i was actually thinking of doing the change, but i diddnt know if i still could.

my bro has about 140k-ish on his toyota, original motor, and when he switched to synthetic, no problems at all (not sure about nissan motors though)

[Musashi3000GT]

You can switch to synthetic anytime, it wont hurt the motor or the seals. the problem is when you switch from synthetic to dyno. the seals and hosses start to shrink and get brittle and break.

[chevytrucks92]

Originally Posted by Musashi3000GT

Go to 3000 miles on regular dyno oil, then after 3000 switch to synthetic.

That's about what I figured. So I'll probably just use the synthetic oil when its due for its first oil change.

Thanks.

[CBFryman]

if you get an oil leak from switching to synthetic it isnt because the synthetic caused the seals to break...its because your conventional oil didnt keep the seals as clean so there was crud blocking the holes....synthetic cleans the crud up and puts it where it belongs, in the filter.

I switched to synthetic 6months and 7,500 miles ago....its just now due for an oil change acording to the oil color. could easily go another 3,000 with out risking anything and probably another 6,000 if i just changed the fitler and topped it off.

Key to good, long lasthing oil is a good synthetic oil and a good oil filter.

i run Mobil 1 full syntetic and K&N Oil Fitler.

[Chiquae07]

so what happens if i switch anf i get leaks? does that mean i gotta get all the seals done again? how much would that be? i currently have no leaks at all.

[CBFryman]

no, find all the ones that are leaking and replace them, or switch back to conventional andj ust add oil unill it dirties up and clogs the hole agian...i suggest the first if you care about longevity...there is a reason the seals where leaking.

[CBFryman]

and even though this is an old thread this is good information.

A friend of mine's dad has a '98 Ram with a cummins diesle. He religiously changed the oil every 35,000 miles with Mobil 1 fully synthetic and only the filter every 7,000...its now running strong with almost 300,000 miles and its never had any problems at all.

[sub006]

Conventional wisdom is to break in a new or rebuilt engine for 2500-3000 miles on regular oil to allow the rings and other friction surfaces to "wear in" to correct tolerances, then switch to synthetic.

Hmm, wonder how new 'Vettes get away with a factory fill of Mobil 1? Anything different about assembly tolerances, metal surface finishing or ???

I have switched to synthetic after 200,000 miles with no ill effects, just extended that particular engine's life (with the help of Lucas Oil Supplement) to 370,000 miles.

I don't think there's anything wrong with "demoting" a vehicle from synthetic to regular oil. Example would be taking a daily driver and relegating it to occasional "extra car" use. Just change the oil more often!

[-Jayson-]

my cobalt came with mobile 1 synthetic from the factory, and thats what im running in it now. It doesnt make sense to use dino oil as a break it, why? If a synthetic oil is what you plan on running all the time in it, break it in like that. synthetic oil molecules are smaller and lubricate better, why would anyone want to make there engine have more friction? I dont see the benefit of that to make it perform better. Not to mention if you do break it in with dino oil, you do get more friction that means more tiny metal particals in the oil, and when you do an oil change to synthetic, some of that old dino oil is going to stay in there, along with the metal particles that are in it.