IF U SWITCH TO SYNTHETIC ON YOUR HIGH MILEAGE CAR YOUR ENGINE IS GOING TO LEAK

kinda the opposite if u switch from synthetic to mineral. is no leak just puff of smoke or worse whole carbon on cylinder.

dat paraffin sludge meme doe

Jokes on you, m8. My rear main seal already leaks.

actually old engines have big thick oil galleries. new engines have pencil thin oil galleries. synthetic oil doesnt sit in a older engine long enough to do its job properly. and with a engine that many miles on it the bearings wont be getting the lube from the synthetic oil either.

>stick to mineral oil in a older engine.

Spotted the Jeep 4.0 engine owner.

Holden 5ltr

>Have 1990 Volvo 244 DL with B230f
>238,000 miles
>Switch to full synth
>No leaks whatsoever

That was 6 years ago.

986/996?

...

This is even worse misinformation than the OP.

Synthetic doesnt sit in the engine long enough? Where does it go? Are you implying that synthetic is less viscous?

rear main seal, oil filter adapter gasket, distributor leaks, and oil cap leaks are all common oil leaks on XJ 4.0 engines. But hey it's just external lubrication right?

It's a waste of money.

Pennzoil Yellow Bottle conventional ftw.

mine calls for this shit, now at 250,000km with no leak.
no idea what the previous owners put in the car but I always use synthetic

What car??

If all your gaskets are fucked then sure. Really I would consider it a good thing because the flaws in your engine are now being pointed out.

I'm just telling you basically what I was told by an oil testing company. They don't see much difference between synthetics and conventionals when tested. The chemist even said he just buys whatever is cheapest which is typically conventional.

The few exceptions are, like I said
>your manual calls for synthetic oil (duh)
>your are in a cold weather area and want to prevent more wear on startup (or you could just buy a lower weight conventional)
>you are extending your oil changes in accordance with the manufacturer's specifications (synthetic tends to hold its life longer than conventional)
If you aren't doing any of the above, a conventional oil is perfectly fine. Especially if you have an older tired engine. They tend to be a little loose and while 5W-30 Synthetic is literally 5W-30, it tends to run a little thinner than conventional 5W-30 due to being made up of homogeneous particles. You may see a little more leakage or burning than usual.

Synthetic vs conventional is simply a debate that doesn't have much merit behind it outside of a few applications is what I'm saying.

>you are in a very cold weather area

well this just means half the people in the world with a car has to use synthetic

"Very cold" being about -20 degrees, and like I said you could also just buy a lower weight conventional. And there are very few places where it's -20 degrees all year.

I'll admit I used to buy into the "Synthetic is instantly better than Conventional because of its properties" concept but after learning this straight from a well respected oil testing company I just stick to good brand name conventional oil. Lower weight oil is added before the winter in accordance with manual specifications but even then, 5W-30 will be okay at that temperature.

Sludge is a grossly exaggerated issue if you regularly change your oil.

This is the theory behind what OP is saying. Synthetic oils are able to clean out built up deposits in the engine, and if those deposits are actually serving to seal the engine, then when you clean them out the seals leak. Allegedly.

does your manufacturer reccomend synthetic? if yes put it in. if no, don't. This isn't hard to understand.

when I used to work at a mazda dealer we had a case where a customer insisted on full synthetic for a older mazda 3 with over 100K miles. Normally we'd explain that the engines aren't designed for synthetic, but in this case the owner was very insistent. The service writer made the owner sign something that basically voided his warranty and we found full synthetic oil from the attached volvo dealer in the same building.

fast forward 3 months and it's in for "running rough and shutting down after driving for a while." another tech got a hold of it but from what i understand was that the oil wasn't able to get up to the right pressure at operating temperatures, and so the whole camshaft/valvetrain basically burned up and "went caddywumpus" because it wasn't getting oil.

it's almost like auto engineers know what they're doing when they say what oil to use, huh

yea this isnt even remotely real you dumb shit.

i use dat mobil 1 synthetic in every car i own even a 300k mile 351 vee ate

you could probably put fucking vegetable oil and horse piss in a 351 and it will run, some engines are much more finicky than others, especially the gen1 skyactiv engine that was in there

Chiming in here, I have an old Merc with 325K on it and counting.
Switched from dino 10W-40 to synthetic 15W-50 and havent noticed any leaks get worse, in fact I think the thicker oil has been good at that. Burns a bit but it always has. Also has some valve ticking when it's cold but it usually goes away within a couple minutes max.

Sounds like a whole load of BS m8.

Same, only i did that 11 years ago

I like to call it "external cooling"

I think thats where it came from, too. The people who mainly perpetuate this idea are older guys.

i use synthetic in all of my shit too.. I have never had a vehicle die for mechanical reasons. Maybe shit 80's electrical reasons but never due to lubrication .

that's just 30 year old engines beginning to rattle themselves apart
just slightly opens up where normal oil can't get through, but thinner synthetics can get into

I have synthetic in my 4A-GE and there are no problems

Bullshit

I wouldn't be surprised, it is a Mazda after all

>previous owner used synthetic blend
Fucking cheap ass. Full synthetic isn't that pricy. It's only at 35000 miles so I'm switching to good stuff

Being this upset over oil is autism

Where do u think u are, niglet ?

Pipe down, small fry

Return from wence you came, plebbitor

Switched both my vehicles over to synthetic and didn't get any leaks (my jeeps oil pressure switch shit the bed, but that's probably unrelated). Then again, both my vehicles don't have real finicky engines, soo...

03 Jetta 24v VR6

do people actually give a fuck what oil goes in their car?