BlueMistDA
New Member
Does anyone know if sythetic oil is bad or good for a high milage engine? I read some forum saying that it causes leaks for a high milage engine over 200k. Anyone know
synthetic oil bad or good for high mileage engine
- Thread starter BlueMistDA
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dc2GS-R
Super Moderator
It can cause leaks.
Petroleum based oil coats gaskets and seals and creates a varnish looking buildup. Synthetics are made to last longer and use more detergent additives. These help clean out the engine and remove deposits and build up caused by running petro. based oil for so long but can also remove deposits on seals that are holding back leaks. I've switched every car I've ever owned to synthetics without any probles with leaks though. (except the RX7 of course)
When you switch to synthetic oil though, it cleans alot of crap out of your engine that petro. based oil builds up or just doesn't clean. So the first time you switch it is a good idea to flush it out because that oil will get real dirty real quick. Everytime I switch a car to synthetics, I will do an oil change with Mobil 1 synthetic. Drive it a 300-500 miles then just change the oil filter and top of the oil. It helps clean some of the crap out of the oil that it has cleaned out. Then I would drive it another 300-500 miles and do a complete oil change. So I only let the first synthetic oil go about 1000 miles with an extra filter change about halfway
As soon as you switch to synthetic it cleans alot of crap out of your engine so flushing it out like that is a good idea so you don't have all that built up crap floating around your engine.
Petroleum based oil coats gaskets and seals and creates a varnish looking buildup. Synthetics are made to last longer and use more detergent additives. These help clean out the engine and remove deposits and build up caused by running petro. based oil for so long but can also remove deposits on seals that are holding back leaks. I've switched every car I've ever owned to synthetics without any probles with leaks though. (except the RX7 of course)
When you switch to synthetic oil though, it cleans alot of crap out of your engine that petro. based oil builds up or just doesn't clean. So the first time you switch it is a good idea to flush it out because that oil will get real dirty real quick. Everytime I switch a car to synthetics, I will do an oil change with Mobil 1 synthetic. Drive it a 300-500 miles then just change the oil filter and top of the oil. It helps clean some of the crap out of the oil that it has cleaned out. Then I would drive it another 300-500 miles and do a complete oil change. So I only let the first synthetic oil go about 1000 miles with an extra filter change about halfway
As soon as you switch to synthetic it cleans alot of crap out of your engine so flushing it out like that is a good idea so you don't have all that built up crap floating around your engine.
Last edited:
cabezzzdb8
BBS wanted
That explains why when I ripped my engine apart that thing was blingin, reason for ripping engine apart ahem" 8 vent valves, bimmer uses motul, manual says is good for 15,000 miles, 
BlueMistDA
New Member
So I have a a DA integra with 230K miles. I just changed the oil pan gasket the other week and am using Castrol GTX, planning on going Castrol syntec. So would you say its fine just to go synthetic. I really dont feel like doing another gasket change if it does leak, but from what ive read it should be fine right?
dc2GS-R
Super Moderator
There shouldn't be a problem with the oil pan gasket if it brand new. There is still the possibility of the valve cover gasket, spark plugs seals and cam seals could leak. But they are cheap and easy to replace so I wouldn't worry about those. At 200k+ miles they probably need to be replaced anyway if they already haven't been
The only thing that would suck is if the rear main seal starts leaking. It is cheap but a little more of a PITA to replace
Again, I've done it on many high mileage cars and had no problem. There is really only one way to find out if it is going to leak
The only thing that would suck is if the rear main seal starts leaking. It is cheap but a little more of a PITA to replace
Again, I've done it on many high mileage cars and had no problem. There is really only one way to find out if it is going to leak
Ghettokracker71
LS/Vturd
I switched from dino oil w/lucas stabilizer (stfu) at over 100k, but I don't remeber -exactly- or even really about where I was when I did it. I've had good success. amazing actually...I originally went to amsoil for one change, and was like "fuck this" (expensive) so now I use royal purple (yes,also expensive) now. I just changed my oil today actually...I still do every 3k. I got better gas mileage (noticeable,like at least 3mpg or better) and my rpms dropped slightly,but it seems smoother....I like it. Some of it is probable mental (plasebo...lol)........
Royal purple + Napa gold oil filter ftw
Royal purple + Napa gold oil filter ftw
graveyardhippie
New Member
mobil1 is usually what i recommend, but now even walmart has royal purple. so i'd go for that, and listen to dc2gsr and u'll have no problems. and in some cars, you may even notice power gains or better mileage