Synthetic or High MIleage?

[at3GG]

Ive heard synthetic motor oil in higher mileage cars isnt a good idea. Something about synthetic being thinner blah blah blah leaky seals blah blah blah. My wifes 99 altima has just over 80k on it, which if you ask me is pretty low for the year....i digress.....im gonna change the oil when it warms up. Should i go with a performance synthetic or something like valvoline's max life?

[ChinoCharles]

In my self-admittedly novice opinion, way back when I had a 1994 Eclipse with about 120K on it and I ran into the same question. I wanted to go synthetic, but the advice I got was that on a car with that kind of mileage that has seen conventional oil its whole life, it is best to just stick with it. I put MaxLife in that car and got another 20,000 miles out of her before I sold it.

[at3GG]

good to know thanks chino! Get that shift knob on yet?

[gid]

went to a syn in 2000 PRIZM ( Corolla ) at around 70,000 miles and it started to burn oil . None before that . Then went back to conventional oil and burned much less . Wonder if it has to with V.V.T.I. ? :iono: . So it's up to you . If uses more , go back to regular .

[YarisSedan]

Synthetic has a higher amount of detergents. So say you got like 150k miles. And you got seals that are sealed up because of the sludge and dirt thats against them. Once you introduce synthetic it will slowly start to clean up your engine and wash away the dirt on the seals which can potentially have them to start leaking. A car thast well kept and has seals that are in good condition should have no problems. If a car has high milage in a short amount of time such as a daily driven commuter car is no problem. On a much older car that is hardly driven or sat for a long amount of time this is a problem. As the oil will settle to the bottom of the pan and allow the rubber seals to start to dry up, crack and then begin to leak. Perfect example

My 89 acura legend. My aunt previousely owned it and it sat for a year out in the sun never driven for a year infront of her house before i bought it. No real oil leaks for first few months after owning it. After i put royal purple in. Week later oil leak. Distributer o ring seal was leaking, then week later oil pan gasket was leaking, then next week valve cover gaskets. Then side valve cover gaskets, When i thought i finally fixed everythign possible. Oil cooler started to look. From my shop to my house 10 miles i lost 2 quarts of oil. After all said and done now my rear main seal is leaking. Not enough that im loosing tons of oil but it is leaking and that requires me to seperate the engine and transmission which i dont feel like doing.

Would all of this have not happend if i had not switched to synthetic? Maybe maybe not. All i do know as i didnt have this problem till after i did. If the car was not sitting out int he sun non driven for a year id ont think i would have as many problems. But stil the car did have high miles and the seals were on thier last leg. But using organic oil probally could have made them last little longer.

[ChinoCharles]

good to know thanks chino! Get that shift knob on yet?

I did and I love it! Thanks again man, that was really nice of you. I promise that if and when I get another knob I'll pay it forward. :smile: