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Synthetic motor oil

Last response: in Cars
September 18, 2011 1:47:05 AM

I have a suspicion that synthetic oil isn't always the best option , but i am not totally sure if i am being paranoid or funny or something . I should also mention that i am not a stranger to things mechanical of nature , i have worked at a kawasaki dealer (in the shop) for a few years and done many of my own auto repairs in adition to working in a small engine shop (power equipment) , but i am not an auto mechanic .I have owned many vehicles with high miles and when i go to change oil , i have no idea what was in the engine so i replace the oil with mobile 1 synthetic and a premium filter . Sometimes i think i notice the engine sounds noisier than before , or i see a 1/2 quart consumed in 500 miles . I am also not so sure i see better mileage with synthetic oil in my engine either .I should also mention that when i see oil consumption i add some lucas oil stabilizer and that seems to slow it down a bit .

I guess I would like to hear if anybody else has had these thoughts regarding synthetic oil .

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September 18, 2011 2:10:11 AM

This subject is a can of worms and filled with a lot of unsubstantiated opinion and few facts.

That being said there is plenty of online technical info. available. Some is subjective opinion and some objective, factual info. In general synthetic oils "can" offer advantages over non-synthetic oils such as higher operating temps., lower consumption, less viscosity index additives (if any), better lubrication, less oxidation, longer oil change intervals, (OCIs), lower friction, better film strength, etc.

Not every synthetic oil offers all of these properties however and synthetic oils vary in base stocks, chemistry and other physical and lubrication properties. You will find tons of oil hype from all oil companies - much of which is misleading and meant to convince you to buy their product. Without a lot of technical knowledge and research on synthetic oils it's difficult to really understand what you are or are not getting with a specific product - in spite of all the marketing claims.

Most German car manufacturers now require very specific full synthetic engine oils that meet their unique engine demands. Big Diesel truck engine makers are also headed this way as the power and load requirements increase. You could spend a couple years getting up to speed on synthetic oil types, benefits and approvals.
September 22, 2011 1:13:52 AM

I am a believer in synthetic oil. I have used it in my vehicles for years and change my oil 2 times a year or every 10,000 miles which ever comes first. My Chevy truck has 190,000 miles and runs like it did at 100,000. I have noticed if an engine is new and not broken in, it will not wear enough to break in. Back in '92 I had a new car that was suppose to get 33 miles per gallon. After the first oil change I went to Mobil 1 and the mileage never went above 28 or so mpg. I went back to conventional until 15k and the mpg finally hit 33 mpg about 8,000 miles on the odometer. I sold the car at 150,000 and it was still running good. I assume the oil was so slick it couldn't break in. Conversely, if you have a weak seal it will find it. I do run 10w40 in the old truck now instead on the recommended 5w30. I may use 1/2 quart in six months.

What really convinced me was working for the power company everything was about saving a penny. When they saw the analysis in chart form of how much longer their equipment was lasting with synthetic oil it wasn't long and there was a complete transition to synthetic, even synthetic grease.

I am not certain if other brands are as good, or if the syn-blend is worth the difference. I also do not know the affect of additives mixed with synthetics.

Good luck!
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September 22, 2011 1:47:41 AM

Synthetic oils are so much better that regular petroleum oils that many car makers now mandate the use of synthetic oil for warranty coverage.
October 3, 2011 11:55:45 PM

I agree that synthetic oils are better but some engines do not like them. I've seen some industrial diesels go through front and rear seals repeatedly because of synthetic oil. Amsoil synthetics do not work in Isuzu diesels but that is because of the additives they put in it. It'll take out injection pumps on 4LE Isuzus. I had a customer who went through 2 sets of pumps because he refused to change his brand of oil.
November 2, 2011 6:27:42 PM

Synthetics are not good if your engine is consuming (burning) lots of oil. I say not good, but really it's mostly that you're burning your money.

If your oil is leaking or burning, your engine is the problem, not the oil.

Synthetics have lots of advantages. Engine will run cooler, higher flash point, better lubricating properties, better stability at low and high temperatures...

With synthetics such as Mobil 1, you can double your recommended oil change intervals with no fear. For better peice of mind, change your filter at 6000 miles and top it up.
November 8, 2011 6:28:16 PM

i run nothing but quaker state "Q" synthetic in my new car with fram filters. i got the car at 50mi so i know its in good hands. i change every 3000-3500 (depending on season of course) as its required by warranty.

it might be unsubstantiated opinion but its fairly common to hear to run either synthetic or standard and to stick with it. some people claim that not heeding this can blow seals out on occassion.

as for which oil to choose....i would really only recommend synthetic for people who drive hard, go for long intervals between changes or have an engine which requires the extra breakdown protection synthetics can offer.

most cars can get away with just using standard oil and changing it at regular intervals.

for cars that leak oil or older, higher mileage engines then i've found that quaker state high mileage with slick 50 works superb. i know someone with an old beater civic with 150k+ miles on it that burns oil and goes without an oil change more often that it should but it works as great as the day it was bought (at around 75k)
November 19, 2011 11:36:56 PM

Even with synthetics should not the oil filter be changed every 3 to 4K? I have never used synthetic oil. Might have to look into it on my next new car.
November 22, 2011 11:15:20 PM

A lot of companies make synthetic oil filters. I've never compared them before though. The only times I open up an oil filter is after a rebuild and I finished breaking in the engine or I have one come in with oil pressure issues or a knock. Then I'm looking for metal and am not really concerned about the filter element.