just purchased my 99 Saturday , 186xxx mi. , very clean . Should I be using synthetic motor oil at oil changes ?

 

That's up to you. I go with high mileage oil. Synthetic may cause leaks to appear as it has lots of detergents that clean away crud build up.

 

I don't see any reason you can't use it. Synthetic oil is good stuff, really no downside except cost. I change mine every 3K regardless, not into extending the OCI's, so I don't see enough value in it.

 

As its been said you may see leaks form because synthetic oil tends to be thinner. They use it in new cars because the seals are new and the tolerances on the motor is tighter. As it has been said high milage oil is the way to go.

 

I run valvoline conventional 10 30 with one quart of lucas oil stabilizer. but you can run what ever you want really as long as you make it full on the dip stick.

 

I'm running full synthetic on my '89 with 225k on the meter. I was completely sold on synthetic oil when (back when I was into aircooled Volkswagens) a guy with a '69 bus rebuilt his engine, and ran synthetic only for 100,000 miles. He pulled it apart and took pictures, looked like it had never been run. If you have to run higher weight oil to keep seals from leaking, you're just band-aiding over problems. I had a few little oil leaks when I first ran full synthetic, but I fixed them, now have no problems. Keep in mind that some higher mileage engines, particularly those with worn out rings, will burn synthetic oil much easier than conventional oil.

 

oops actually i meant 86k miles , NOT 186k ! thanx for all the advice guys.

 

X2 lucas is great stuff

 

Fake oil's molecules are all the same size - dino oil's molecules are all kinds of sizes. The larger molecules in dino oil tend to plug small leaks better.

The hype is fake oil withstands a higher temperature before it breaks down - true. But hey Buddy, if your engine gets hot enough internally to break down real oil you have major problems anyway - it's dead!

One of the reasons we use oil in the first place is it carries heat away from the hottest parts - bearings etc. 50% of the engine cooling is done by the oil. (Read about oil coolers.)
Fake oil doesn't carry away heat as easily as real oil - parts will run hotter. People like Currie - who make the best diff gears - their warranty is voided if you use syns.

The hype is fake oil needn't be changed as often. The reason we change oil is to get rid of the contaminants from combustion. Nothing stops the burning process from producing carbon particles, water, and acids in the crankcase - unless it prevents your engine from running at all.

But - mfgrs, suppliers etc all love it - it's a very high profit item.

Drive through Texas - see all those little buildings that disappear when you look right at them? Synthetic oil wells.

Synthetic - fake truth.

Avoid oils that use gimmicks to make you think they are special - ie: Adding food coloring to oil does nothing.

Quality Oils designed for automotive use already have all the additives needed to keep it slippery and working properly. Dumping snake oils in only dilutes and can counteract the lubrication properties.


If those snake oils were beneficial, don't you think the oil companies would add them and brag about it?

OIL DESIGNED FOR YOUR JAPANESE CAR - 10-30 WITH TERRIYAKI!
FOR YOUR FERRARI - 20-40 WITH OLIVE OIL
30 WT WITH KROUT!
KimChi 20 WT
MERLOT 40?

For the younger crowd - 10WT with "Nestlies Quick!"

Use quality oil with a quality filter, change them frequently.

Remember paper and the internet don't reject words - lies and hype look real.

 

Wow feel better? I understand you are trying to make a point, tone it down a little, the guy is just asking a question and people are responding with what they believe and have tried, not trying to tell you that you cant have an opinion, but don't blast people with nes quik crap.

 

Most importantly, use a quality oil filter as rrich stated. Wix, Napa Gold, Mopar or Purolator. Orange filters with bedliner sprayed on them should be avoided at all costs. Keep up on your oil changes. I like Rotella oil.

 

I was of the understanding that a significant portion of the carbon particles and other items that built up are there because of the traditional oil (which contains hydrocarbons) coating the cylinder walls getting burned and going through a reactive process. The idea being that synth oils don't react as much, and therefore reduce the amount of those substances that build up in the first place.

I'm not saying the aren't some carbon particles being blown up peoples' behinds by the synth manufacturers, but there seems to be enough objective study and science behind it to show that there is some benefit.

 

I run full syn in mine. Mostly Amsoil AMO, always use a qt of MMO also. Using a quality filter that lasts is part of the key to extended intervals. In theory, as long as your oil and filter are rated for longer intervals then it should be fine.
Ultimately, if you are that **** about your oil quality, then get it tested every month or so or every XXXX amount of miles. oil analysis lab and blackstone labs both offer this.

 

You may want to consider oils used in the diesel market as well.

Rotella 15/40 contains detergents that are not common in oils for gas engines and keep that engine cleaner.


X2 on the Lucas additive. I can say that in 15 liter Cat diesel engines, at least the ones I've owned, the Lucas made a difference in operating temp, fuel mileage etc...

I started running Rotella in my Harley's engine, primary box and transmission and noticed less drive train noise and cooler temps over synthetics.

 

Who did I blast?

If you take it personally that's your problem, not mine.
If you don't like what I say - don't look!
If you choose to believe internet and advertising bull - go ahead, somebody has to.


The carbon is caused by incomplete combustion in the chamber - gasoline combining with Oxygen creating heat, resulting in H2O, CO2, CO AND C - and a teeny bit of NOx. Products of normal combustion. Some of it works it's way down past the rings into the oil.
Water - a product of combustion - gets down too and mixes with the oil and unburned HC - it eventually creates acids that can eat everything.
Changing oil - dumping it out of there is the best way to get rid of the pollutants. A good quality filter screens out the larger chunks, but the very fines are still circulating.

Try heating the oil up on the stove with a thermometer. No carbon deposits til about 650-700 degrees - about the same temperature your rings lose their temper (tension) and collapse.

Syns can go hotter - at what temp does aluminum become plastic/pliable at? (pistons, bearings etc.)


The latest trend seems to be re-refining the oil - it's becoming more popular. If it's done right it's no worse and no better than "new?" oil pumped out of the ground.

But again --- QUALITY is important.

Jeep oil filters are often on their side or upside down. The anti-drainback valve in El Cheapo filters often leak causing oil starvation on a cold start.