bluesilver82

I am sure this question has been asked but here goes. I have an 82 with 120K on the original motor. If I swap from conventional oil to synthetic will it pose any problems? I have been told that it can produce leaks and smoke caused ny the dtergents in the synthetic cleaning gunk out and damaging brittle seals. Is this true?

funymuny

One of the real experts can chime in but I tried the same with my 82. The new synthetics are much 'slicker' than conventional oils; much smaller molecular structure I believe which is beneficial to newer engines with very small tolerances. What I found using synthetic was that it will find a leak where I did not know one previously existed (eg, rear main seal). Obviously the seal was worn but dino oil did not get through like the syn. I replaced the seal and went back to conv. oil. No problems. Change the oil regularly/frequently and I believe there is no appreciable difference on these older motors. I use syn. in my new vehicle. Engine wear may one day become a thing of the past......

Mark

Disco_Mike

ive switch to synth in my 79 L82.
The only problem I have is the rear main seal leaks a little more.
It needs replace anyway.

Jud Chapin

I have a '76 and switched to synthetic several years ago without issues.

RxForPain

I have gone to a blend myself. I sub. a quart of Mobil 1.

stock76

I have used synthetic in my 76 L-48, 118,000 original miles for the last 8 or 9 years. No issues.

Dirtbuster1

I use synthetic oils in all my cars. I do not recommend trying to break in a new engine because it will take a lot longer to accomplish. ( Do to less friction) However all synthetic oils are not truly synthetic. Any oils that have synthetic properties can be called a synthetic. This has been proven in court. A true synthetic oil has identical molecules that reduce wear, and friction. Less friction means longer life.

Mobil 1 is probably the only true synthetic on the market. It cost more, but you get what you pay for. As far as cleaning the engine gunk out on a older car, any high detergent quality oil will do that. Depending on which synthetic oil type you use, it can cause premature seal failure. Ther 4 different types. Mobil 1 is a PAO type synthetic oil that is compatable with any other types of mineral oil. I have talked with several Mobil engineers that I personally trust, and they run their oil changes up to 15K miles before changing the oil. However they change the filters at either 3000 or 5000 miles. I change my oil at 10K miles. Hope this might help!

bluesilver82

Thanks.....I was thinking of swaping to Mobil 1 20w-50. I just dont want to start sprouting leaks. Maybe A blend of conventional and synthetic (Mobil1) would be the way to go. Im just not sure.

kayosnes

I use syntetic in the engine, transmission, steering and diff. no leaking.

hot rod performed a test where they changed all oil to syntetic. And dynoed the engine before and after. It showed an increase in hp and torque when using syntetic

7T1vette

I'm not sure what benefit you would get by using a "blend" of organic and synthetic oils. If you are looking to reduce friction [and wear], plus extend oil change intervals, you want to go full synthetic. If you do, some minor leaks may show up...but only because the seal/gasket is getting worn anyway. If you want to save money on oil changes (but don't care about better life and durability of engine parts), keep using organic oil.

LXXVIII

I run Synthetic in my 66 Mustang and conventional 20/50 or 10/40 in my 78 C3. Synthetic has better consistent viscosity (the oil’s ability to flow) making it flow better through the engine. If you do not take your engine to the extremes, conventional oil is fine as long as you change it regularly. Synthetic is also less likely to “gunk” up – again the viscosity reasons. A synthetic will not allow your engine to break in when new and you could see blow by with older engines. That will be determined by the condition of your engine. There are synthetic oils that state they increase gas mileage and engine wear, but I have not been able to see real proven data – other than their brochures which will be tested in a Lab environment which in most cases is WAY of field trials on large populations.

Bottom line, my opinion, I do not see a difference in either one of my cars…Your honey, you decide the necture…

bluesilver82

I am trying to get more life out of an older engine....Does synthetic affect oil pressure?

LXXVIII

I had no noticable difference when I went to synthetic for pressure.

Jud Chapin

The only real way to see the results of synthetic other that gas mileage is to measure internal engine components before using synthetic and then running the car for many, many miles and then rechecking them.

Have a look:

http://www.mobiloil.com/USA-English/...Las_Vegas.aspx

HamadUP

I heard that the original (or old tech) seals on the old engines are not compatible with synthetic oil, ie they cant hold that kind of oil inside. so, even if your seals are good still they will leak. thats why you can use synthetic oil on a freshly rebuilt engines, because all the seals were changed with new, synthetic oil compatible seals.

After all thats what I heard, not sure if correct, someone will correct me.

I'm Batman

GM uses Mobil 1 as the oil from the very start for new Corvettes...I guess Z06 engines never break in.

The seals are compatible, if they're worn out you'll likely see more leakage with synthetic.

FKING1

I wouldn't do it in my 70 L46. The rear main leaks a little now and no telling what synthetic would do! Why ask for trouble?

SanDiegoPaul

Never change the oil diet on a 100K+ motor. Don't change anything!

birdsmith

Just my opinion, and everybody knows what those are like, but for my money spending upwards of 5 bucks a quart on oil to save maybe 5% on gas on a car that is (probably) a weekend cruiser doesn't really make financial sense, especially with the extra leakage that I can personally attest to from using synthetic oils. The primary advantage that I have witnessed with synthetics is that their film strength holds up and they (typically) won't break down until well above 300 degrees. Great for racing engines that have a high probability of seeing those kinds of temps on hot days, but of dubious value on most street-driven cars under almost any conditions. If you want to use synthetic oil because it's just plain better oil, fine. If you want to save money, buy Rotella at Wal-Mart.

I'm Batman

I like synthetic not for any potential fuel savings, but for the improved engine wear properties.