Synthetic Oil vs. Regular Oil, which is better?

shores · Post by **shores** » 16 May 2010, 14:40

i have 110,000 miles on my car and it does not leak any oil. have always changed the oil around 5000 miles. have never used synthetic on it before. have heard I have too many miles to change over to synthetic now. That it could cause my seals to leak. Have heard the opposite that if I don't have any leaks that it will be fine. has anybody switched over to synthetic on this model? let me know if you did and if any problems please. thanks.

Post by **egads** » 24 May 2010, 05:29

I switched to synthetic on my v70 with a similar engine at around 220 000k and the engine loves me for it. runs smoother and PCV is now staying clean and no sign of any leaks even though it was on dino oil for the start of its life. Quality synthetics are well worth it.

cet · Post by **cet** » 24 May 2010, 07:07

If you look at the signature profiles of the moderators, you will notice that a number of them list the use of synthetic oil in description of their cars, so i would guess they rate it as a positive factor.
But the previous post hits on the key factor of your worry; leaky seals. Oil made from pre-Cambrian ferns and dinosaur guts contains wacky organic compounds that degrade in to sludge and crud when cooked in a gasoline engine. The best way to get leaky seals is to use dino oil and never clean the PVC loop on a car with a ridiculously complex PCV loop, like a Volvo.
Even for a good oil changer such as yourself, the crud cooked out of the oil instilled at the factory, when the car was new, could still be in there.If enough of it builds up one of the 4 (or 5 ) passages in the oil seperator gets occluded (or one of the lines), the blow-by from the pistons has no where to go, so it presses oil out the seals as it tries to escape.
I dont think they are build up free but i would wager that synthetics have far less, any long term users wanna testify?

FCPEURO · Post by **FCPEURO** » 25 May 2010, 18:47

Go with Synthetic, you will not have an issue.

Post by **FlyingVolvo** » 25 May 2010, 20:01

Most dino oils are good for 5000 - 7500 now depending on your driving. Nearly all good synthetics can now easily do 10,000 miles, and quite a few up to 15,000 or so.

www.bobistheoilguy.com for more info than you ever wanted to know on oil!

I (and they) highly recommend Pennzoil products. Ultra so far has been a great oil, and Platinum has a great history.

Post by **JimBee** » 25 May 2010, 21:44

I ran my '87 Nissan to 202k when I had to stop driving it due to a rusty crossmember. It never consumed or leaked oil and after parking it for 6 months before I sold it, the thing amazingly started instantly as it always had--even without running it or charging the battery during that whole time (November to May). That car had used Amsoil since just after it was broken in. I'm a fan.
Then I bought the current '93 850 20 valve 5 speed with 151k. The oil was dirty, but still ran it from November to May of the next year before changing. I don't put on a lot of miles. I changed it to Amsoil and ran it for a couple of months. I could feel a difference in performance and there's no black smoke. When I bought the 850, the inside of the tailpipe had a thick coating of black soot. I will say that if I wind it up hard through the first 3 gears a few times, I find a little oil on top of the engine; if I drive it a little spiritedly but not really crank it oil stays in. Seals seem o.k., no spotting. Last oil change, switched to Valvoline full synthetic and don't notice a dfference (Kmart had it on sale for 5 bucks a quart; Amsoil is pricier.) I'll stick with synthetic.

mcage228 · Post by **mcage228** » 27 May 2010, 06:06

Check out Amsoil.com they were the first with sythetics. Full line a 100% synthetic products. I've laced my autos and trucks with amsoil for 30 years, gear lube, trans, engine oil. Most of time picked up anywhere from 3-5 mpg (depending on vehicle) along with peace of mind your running with the best,imo. Very hard to hurt there products. Just laced my sons 2000 V40 130k + miles. Don't know that its all from synthetic but the car definitly runs smoother, shifts nicer and is very responsive. Haven't checked the milage yet. Anyway cruise all around there site tons of good info. Hope this helps and take care.

04XC90T6AWD · Post by **04XC90T6AWD** » 27 May 2010, 06:46

sythetics Unlike conventional oils that are produced by distillation and further refining of existing crude oil stock, synthetic lubricants are made through chemical reactions. These oils aren't synthetic or artificial in the sense that they're manufactured out of whole cloth or somethin like that they still have the same natural ingredients found in "real" oil. But the differance in a synthetic lubricant, these ingredients are recombined in order to yield a synthesized-hydrocarbon molecular chains with much better characteristics and uniformity not found in even the highest-quality conventional. Synthetic oil's molecules are much more consistent in size and shape, they are better able to withstand extreme engine temperatures. The unstable molecules in conventional oil can easily vaporize or oxidize in extreme heat. synthetic oils are chemically produced, there are no contaminants in the oil. Conventional oils contain small amounts of sulfur, wax, and asphaltic material that can promote detonation as well as varnish and sludge buildup. With no wax, synthetics will flow at much lower temperatures than conventional oils. In fact, synthetic oils are now available with viscosity ratings as low as 0W-30. You might get more horsepower only about 7 or so and a smother running engine possibly longer lasting but keep in mind your driving habits contribute to how long your car lasts as well. There is alot of misconception about sytentic oils. For example, "if i use sythetic oils i cant ever swtich back to conventional oil." Well that is absoultely not true at all in fact conventional and sytenhtic oil can be switched on and off with no problems. You can even mix the two toghether it will provide better lubrication! Also remember that conventional is 80% base and 20% additives those are your detergents and etc. Conventional oils arent true base stocks they are instead sytnesised hence the name syenthtic.

If you do decide to mix the two toghether Synthetic and conventional will not "mix" and synthetic creates a barrier on moving parts, that conventional cannot pass. So, too much synthetic, as in say a 50/50 blend, will be like running an 8 quart system on 4 quarts, without starving the oil pump. It will break the synthetic oil down quicker.
The correct combination will give you no problems and will yield the benefits of both conventional and synthetic. With Engine/Motor Oil, the maximum amount of synthetic recommended is 25%. Foaming will develop if more is used, and the foam will counteract with lubrication. Higher-priced synthetic blends have more synthetic and/or more friction modifiers. Synthetic Blend as mentioned earlier is not as cost efficient as adding your own bottle of full synthetic for every 3 quarts of conventional. Just make sure the weight is the same.

shores · Post by **shores** » 02 Jun 2010, 18:42

was talking to a Saab mechanic and asked him his thoughts about this, and he recommended synthetic for any car that has a turbo. Said it was fine to switch over and would not mess up my seals.

jtz54 · Post by **jtz54** » 10 Jun 2010, 15:57

Use sythetic oil but with a few ounces of AutoRx. The syn oil tends to dry out rubber seals.
The AutoRx has lanolin and conditions the seals. Don't laugh, it works. I also run my syn oil
to 10K miles which makes up for the cost diffrence in oil.