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synthetic oils

4951 Views 15 Replies 12 Participants Last post by  vncj96
Does anybody really have a strong opinion on the synthetic oils? I buddy of mine wanted to put Amsoil in all his cars so we registered for an Amsoil dealership. He put it in an 03 H2 and a brand new maxima and says its great but I haven't done it yet. I've heard that switching to synthetic on older high milage vehicles makes them more prone to leaks and that its too late to justify the expense of the synthetic over normal.......
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Synthetic oils are great. The friction is a lot less inside the engine, so there is less wear on the parts, lower temperature, better power, better gas mileage....etc. It also gets to operating temperature faster and is not as thick when it is still cold. The problem is that in any motor that runs with normal oil, there is carbon buildup inside the engine. The more miles, the more. If you put synthetic oil into a high mileage motor that always had mineral oil before, these residues can break free and ruin your gaskets, seals and even pistons, valves etc.
If you put synthetic oil into a high mileage motor that always had mineral oil before, these residues can break free and ruin your gaskets, seals and even pistons, valves etc.
I've heard about this before. The question is when is too late to start using synthetics?
As far as I know about 60,000 - 70,000 mls, although that greatly depends on driving style.
driving style.
Well, when I was younger I used to have a lead foot. Now, It's more like a helium foot.
so at about 190,000 miles I should probably stick with the mineral oil? ;-)
I bought my 98 with 178xxx on the ticker. It would use a quart of regular oil in 3500 miles. Now that I use synthetic, it doesn't lose/burn any in 4,000 miles. It doesn't rattle as bad when I first start it. And I gained probably half a mile to the gallon.I use synthetic in anything/evreywhere I can..
Hmm, I think I might want to switch to synthetics. Anyone have anything they like better than anything else?
amsoil is the best out there i have a 86 gmc c1500 pick up at 185000 i changed to amsoil when it was about 2500miles i was losing oil pressure spoke to oil rep he said change oil filter an oil pressure came back up it was cleaning the inside of the motor now i have 210000 on motor an runs better then ever just bought my supplies for my 2001 chevy 2500 burb cost about 100 bucks but that was 2 oil filters,case of 5w30 air filter an motor flush my truck has 97000 it will have amsoil till the day i die my boat also has amsoil products in it hope this helped with question johnny
Re: RE: synthetic oils

Steve said:
If you put synthetic oil into a high mileage motor that always had mineral oil before, these residues can break free and ruin your gaskets, seals and even pistons, valves etc.
I've heard about this before. The question is when is too late to start using synthetics?
I have used synthetics and blends for years. My first experience with synthetics dates back to the 80's with a tiny oil company called NEO At the time I was driving a newer Triumph TR7 and the engine developed an oil leak on the end seals on the camshaft cover. NEO explained that the end seals were made of a type of rubber (carbon based I think) that their oil dissolved. New seals from an American mfg. did not have any trouble with the sythetic.

Later in life I had a 100k+ mileage Dodge minivan that burnt oil like an oil field attacked by Saddam. Huge plumes of smoke trailed that van everywhere it went. By switching to Valvoline Synthetic the smoke was reduced by 99%.

I bought my 93 burb with 200k on the odometer, and I put Valvoline synthetic in the crankcase and Amsoil in the differential, and it is running great.

I think that the 'synthetic oil caused my engine to leak, blow up etc.' is more legend than truth. Maybe others will chime in with their experience.


Just my opinion, I could be wrong :mrgreen: :mrgreen:
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I started using Mobil 1 in my 'burb. It has 120,xxx miles on it. Been using it for more than a year. No trouble. Seems to run better than ever.
I've always run Mobil 1 in my vehicles. No problems yet.

Here's another good site you might check out: http://bestsyntheticoil.com/dealers/amsoil/seals.shtml
Bought our 1990 GMC Suburban in 1996, when it had 100,000 miles on it. I immediately started using Mobil 1 synthetic oil, and started using a 2 quart oil filter. It has 336,000 on it now, and believe it or not, that engine doesn't burn nor leak a drop of oil! I have put two transmissions and two rear ends in this vehicle, but have only changed plugs, wires, distributor cap, and oil and never have had a problem with the engine.
Amsoil is definetley good but royal purple is just as good or better i use it in my crankcase with 170000 miles and the rear end i'm about to put it in the tranny. When i changed over from regular gear oil to royal purple 75 90 in my rear end i got 1.5 more mpg average that is just rear end oil!
The old man just started using synthetic in his NBS 07 with the 6.0 max, he has seen a 1.5 mpg raise! And considering how ling you can go on synthetic and how many miles a year he puts on he will only need two changes a year and save a ton of money
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