Synthetic Oil....

[jwk316]

I have a 98 Mistubishi Galant with about 100k on it and was wondering if it would be smart to switch to synthetic oil or stick with the basic oil. What are the benefits for switching and what are the pros and cons between the two and what not. Thanks much.

[goongrinch]

dont switch to synthetic now, go with a high milege oil, synthetic is more slippery then conventional oil and with 100k i bet u would notice more leaks using synthetic

[bluevp00]

Well does your car burn oil right now, or does the oil level remain constant between oil changes? If you aren't experiencing any oil burning problems now, then it should be ok.

Just keep in mind though, that synthetic oil has really good cleaning properties, and it may dislodge sludge that has been built up over time - thus leading to an oil burning problem. I'd suggest first switching to a synthetic blend oil before going to a full synthetic, so you can guage your car's reaction to the new oil.

[jwk316]

I believe it burns a lil oil. I just want to move up in technology and i guess synthetic oil is suppose to be good for old engines as well. If it burns oil i guess ill just have to add it when needed. Not a big deal. I am going with amsoil 10w30 and i can get a 25000 mile or 1 year oil change out of that. I will make sure and flush on the engine first with a flusher of some sort. It also says you will get about a 9% fuel economy increase. Synthetic has me hooked and its so easy to. I dont see a thing wrong with it. Nothing is bad at all.... Except it cost a lil more at hte time, but in a year i would have around 9 oil changes and i can put it all into 1. So in the end its way way way cheaper.

[Steel]

eee... synthetic is great, but i wouldnt want to stretch the change interval much past 15k miles, and the filters past 7.5 or 10. I use synthetic and change it ever 10-12 k. If you really want to do 25k miles, get an oil analysis done at 15k just to make sure its doing its job, if so, have at.

[bloodyprice]

deffinately go with synthetic, it is actually man made and filtered, and isnt just full of additives like conventional oil. plus synthetic coats the high friction points more(where conventional splashes around and runs off), dont listen to those morons who say use a thicker oil for older or high mileage cars, that will keep the oil from getting to tight friction points. plus conventional oil drains to the bottom of the pan wereas synthetic has the ability to "stick" or stay where it was and all the oil dosent drain to the pan. this helps eliminate hard and dry startups in the morning. switching to synthetic is never too late. <<<my honest opinion

[534BC]

I do recommend synthetic for any mileage vehicle except perhaps an oil burner/leaker or one that gets very few miles on it. I also have run miles way over 50,000 on various vehicles and recommend extended drain intervals similar to what Amsoil does. Change filter in-between if it gets plugged.

As far as the weight, if the pressure is very low because of high temps/high clearances then increase weight of the oil.

Don't expect any increase in power/mpg to speak of.

[curtis73]

I have to chime in... there is a bit of misinformation here that should be cleared up.

Synthetic oil is not necessarily man-made. Good ones like Mobil 1, Royal Purple, and Amsoil are synthetic esters made in a lab. Cheaper synthetics come from the ground crude like normal oil, but since they meet the API's standards for purity they are legally allowed to be labeled synthetic.

Also, synthetic oil is not more slippery. It does not provide a different friction environment for the bearings, its oil plain and simple. Its properties are very similar to regular oil, but its big benefit is purity. It not only starts with more stability due to its purity, it can dissolve and hold more impurities which can (notice I said "can") extend oil change intervals. Each engine is vastly different in how it contaminates oil, and extended changes should be accompanied with an occasional (maybe yearly) oil analysis.

[Knap]

Synthetics are based on PAO (Group 4) or Group 3 mineral oil or a mix. Esters (group 5) which are polar are used but the % varies. M1 may use 3% with AN (group 5) although other road oils may use say 10%. Race oils tend to use say 20% or higher examples Motul 300V Fuchs Titan GT1 and Redline. Some of the advantages in race oils is that they thin less at high temperature and can avoid using viscosity improvers plastic polymers that shear.

With group 2 and group 3 minerals being used in current spec oils they are of high quality and anyway all oils rely on the additives such as ZDDP as anti wear anti oxidant and anti corrosion.

In general synthetics keep clean rather than clean, however esters do have a cleaning action, have less internal friction and are less prone to sludge and varnish as well as being able to handle longer OCIs.

The bearing temperature is closer to 150c so HTHS is a better measure of viscosity and a Redlene 5W20 is 3.3 compared to M1 0W40 at 3.6, so not all synthetics are created equal.

For a road car choose an oil that suits your requirements.

[Black Lotus]

Originally Posted by jwk316

I have a 98 Mistubishi Galant with about 100k on it and was wondering if it would be smart to switch to synthetic oil or stick with the basic oil. What are the benefits for switching and what are the pros and cons between the two and what not. Thanks much.

If it's turbocharged, moving to a full synthetic and changing it often is always helpful. If it's not turboed, stick with regular oil and change it often. And don't use additives.