Synthetic VS Regular Motor Oil

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I have seen no conclusive evidence that says it's worth my dollar to use synthetic oil.
 

amdskip

Lifer
Jan 6, 2001
22,530
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Originally posted by: Sundog
AMSoil 0W-30 Changed every 12 months or 25K miles...whichever occurs first. Filter chanhed at 6 mo. intervals.

Last oil had 20,000 miles.....previous oil change had 18,000 miles
Same here, once a year oil change with AMSoil. At most I'll put 10,000 miles on my car. AMSoil IMHO is the best out there. The stuff works great in the powerglide in the dragster and keeps things nice and cool.

 

Originally posted by: Sundog
AMSoil 0W-30 Changed every 12 months or 25K miles...whichever occurs first. Filter chanhed at 6 mo. intervals.

Last oil had 20,000 miles.....previous oil change had 18,000 miles
Mabey thats why your block only lasted 160K miles.
 

Sundog

Lifer
Nov 20, 2000
12,342
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Originally posted by: SampSon
Originally posted by: Sundog
AMSoil 0W-30 Changed every 12 months or 25K miles...whichever occurs first. Filter chanhed at 6 mo. intervals.

Last oil had 20,000 miles.....previous oil change had 18,000 miles
Mabey thats why your block only lasted 160K miles.



Incorrect.....the Taurus ran on Dino oil until the day it died. Block change was unrelated to anything related to oil.
 

OrganizedChaos

Diamond Member
Apr 21, 2002
4,524
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i use 89cent a quart cheep stuff. as long as its 5w-30 and its the correct service grade i don't care who makes it. i figure so what if the dino oil breaks down faster, its only gunna be in there for 3000 miles. alot depends on the engine though. 4.0L OHV engine has never been reved over 4k. if i had a high rpm 4 banger or a CTD that took 4 gallons of oil i'd be using AMSOIL with a external oil coooler, bypass oil filter (thers a big diffrence between 20 microns and .1 microns), some neodynium magnets glued to the filter, and a good oil pressure gauge.
 

CFster

Golden Member
Oct 16, 1999
1,903
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Mercedes and BMW have started having 15K to 20K mile first oil change intervals - they come with Mobil 1.

I use it in my car and go 7500 between oil changes.

Anybody who is changing their oil every 3K on regular oil is doing it too often. It's simply not necessary any more as new cars run a lot leaner, and the oil doesn't contaminate as quickly. 5K is a reasonable number - unless you drive a taxi or something. Go look in your owner's manual. Usually 4500 to 5000 for severe service and 7000-7500 for normal service.

It works for me, and for the fleet of 100+ vehicles I'm responsible for.

Oh and by the way, the color of an oil is Absolutely NOT an indicator of it's condition.

As for synthetic causing leaks on older vehicles, I've had that problem before with Valvoline sythetic.






 

Nebor

Lifer
Jun 24, 2003
29,582
12
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Originally posted by: CFster
Mercedes and BMW have started having 15K to 20K mile first oil change intervals - they come with Mobil 1.

I use it in my car and go 7500 between oil changes.

Anybody who is changing their oil every 3K on regular oil is doing it too often. It's simply not necessary any more as new cars run a lot leaner, and the oil doesn't contaminate as quickly. 5K is a reasonable number - unless you drive a taxi or something. Go look in your owner's manual. Usually 4500 to 5000 for severe service and 7000-7500 for normal service.

It works for me, and for the fleet of 100+ vehicles I'm responsible for.

Oh and by the way, the color of an oil is Absolutely NOT an indicator of it's condition.

As for synthetic causing leaks on older vehicles, I've had that problem before with Valvoline sythetic.

I don't change my oil early for the car's sake, I do it just to kick mother nature in the balls. :thumbsup:
 

PeeluckyDuckee

Diamond Member
Feb 21, 2001
4,464
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For an old vehicle switching over to synthetic is a bad idea as, like others have said, it will cause leakage. That's how the engine went kaput in our family '85 Bonneville. Bro forgot to check the oil one day as he normally does once every week and drive oil-less for about 8KMs and that's when he heard loud KNOCKING noises coming from the engine bay.

 

B00ne

Platinum Member
May 21, 2001
2,168
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Originally posted by: Ilmater
Don't use synthetic on a car with 90k miles on it. Other motor oils can leave a lot of gunk in your engine. If you switch to synthetic now, it will clean all that out. That sounds great, but actually that could cause your engine to leak. Only use synthetic on a reasonably new car and continue to use it. And I refuse to answer your second question. While you don't HAVE to stick to synthetic, you'd be ignorant to buy a car and use synthetic for a long time and then switch to an inferior oil.

Amish, stop being paranoid. Mobil 1 won't hurt your engine, and neither will any other major synthetic oil. All it will do is protect your engine better than any non-synthetic oil on the market. However, I wouldn't count on it lasting 5k miles. I've heard that it burns off a little easier than most oils and should be changed as usual every 3,000.


??? Huh every 3000 miles - here in Europe the regular change interval is 15000km (9500miles) some cars even have that increased to 20000 miles. Probably the Oil industry tells you to change oil that often.
 

TechnoKid

Diamond Member
Feb 12, 2001
5,575
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I encourage everyone to read this

Mobil 1 is a very good synthetic, and can go the distance with proper used oil analysis (UOA). If you really want to go over 7500 miles for an OCI (oil change interval), then I highly reccomend you get a UOA done to determine what OCI is best for you. UOAs will show wear metals, your TBN(,which is a number that determines how much additive is in the oil) fuel dilution, water content(if any) . Additives is the detergents that keep your engine clean.

There are many factors, which include whether or not the oil gets up to operating temp everyday to if the car is only driven less than 5 miles each way (short trip driving) or idled for a long amount of time, that determine whether you should change your oil sooner or later. How much top-up/make-up oil you use can affect how often you must change the oil. Oil sump capacity can determine OCIs. Fuel dilution (how much fuel is present in the oil) is high on cars that idle for long periods and cars that oil does not regularly see operating temps. A 15 minute drive on the freeway is sufficient to get oil up to temp to allow the cleaning additives and detergents to work their best.

If you are shooting for 10k intervals using a synthetic, make sure your filter can handle that, some are purpose built for long OCIs and some may require a change midway (in which case the make-up oil added for the lost oil from the filter change would help to replecnish the TBN of the oil). The way you drive can affect how often you have to change the filter. If you do not have a good air filtration system, then that dirt goes right into your oil, and your oil filter will not catch everything. Bypass oil filers can help catch smaller things missed by the air filter and missed by the full flow.

you can learn a lot more by reading the many posts on the forum on http://www.bobistheoilguy.com and I'm sure Eli will chime in sooner or later.
 

OS

Lifer
Oct 11, 1999
15,581
1
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Originally posted by: Apex
Depends on the vehicle. It's probably not worth it for most cars.

For turbocharged vehicles, it's probably worth the money. The blades run about 1250 degrees F, and the extra heat stability of synthetics will give you an increased measure of protection (especially if you run em hard and don't bother cooling them down before shutoff).

Edit: fatfingered the post.


This is a pretty good approach, for most people, there's really no benefit. At 2.33 a quart though, it's almost a shame not to use it. :D

I do use mobil 1 myself though, but i drive around WOT. Plus supposedly synthetic doesn't varnish your engine internals. :p
 

TechnoKid

Diamond Member
Feb 12, 2001
5,575
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Originally posted by: PeeluckyDuckee
For an old vehicle switching over to synthetic is a bad idea as, like others have said, it will cause leakage. That's how the engine went kaput in our family '85 Bonneville. Bro forgot to check the oil one day as he normally does once every week and drive oil-less for about 8KMs and that's when he heard loud KNOCKING noises coming from the engine bay.

Syn will not cause leakage directly, but that leak was already there; gunk from dino oil was left behind and "sealed" failing seals in the engine. When syn comes in with its better detergency, it cleans off this stuff that was otherwise keeping your already failed seals sealing. I've switched to syn on both hondas in the family at around 60k and have had zero problems. Of course, it never burned oil before and still doesn't. If you are already burning oil with dino, your condtion will most liekly burn more when switching to synthetic.
 

OS

Lifer
Oct 11, 1999
15,581
1
76
Originally posted by: cavemanmoron
I recall a test for Mobil 1 they put it,and soem other non-synthetic oil in a Cold freezer,
like -30f if I recall correctly,and the non-synthetic oil was like Molasses,the Mobil 1 was pourable.

I have vials of oil, castrol GTX 5W-30 and castrol syntec (german variant) 0W-30. Stuck them both in the freezer for a day, pulled them out. No visible difference in viscosity.
 

TechnoKid

Diamond Member
Feb 12, 2001
5,575
0
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Originally posted by: OS
Originally posted by: cavemanmoron
I recall a test for Mobil 1 they put it,and soem other non-synthetic oil in a Cold freezer,
like -30f if I recall correctly,and the non-synthetic oil was like Molasses,the Mobil 1 was pourable.

I have vials of oil, castrol GTX 5W-30 and castrol syntec (german variant) 0W-30. Stuck them both in the freezer for a day, pulled them out. No visible difference in viscosity.

Would the GTX you are using in this test happen to be the newer GF-4 API SM rated oil or the older GF-3 API SL oil?

The german castrol 0w30 is a very good product!....so you are an oil conessieur like me eh?:p
 

Eli

Super Moderator | Elite Member
Oct 9, 1999
50,419
8
81
Originally posted by: OS
Originally posted by: cavemanmoron
I recall a test for Mobil 1 they put it,and soem other non-synthetic oil in a Cold freezer,
like -30f if I recall correctly,and the non-synthetic oil was like Molasses,the Mobil 1 was pourable.

I have vials of oil, castrol GTX 5W-30 and castrol syntec (german variant) 0W-30. Stuck them both in the freezer for a day, pulled them out. No visible difference in viscosity.
There is a huge difference between 32ºF and -30ºF as far as oil is concerned.
 

OS

Lifer
Oct 11, 1999
15,581
1
76
Originally posted by: TechnoKid
Originally posted by: OS
Originally posted by: cavemanmoron
I recall a test for Mobil 1 they put it,and soem other non-synthetic oil in a Cold freezer,
like -30f if I recall correctly,and the non-synthetic oil was like Molasses,the Mobil 1 was pourable.

I have vials of oil, castrol GTX 5W-30 and castrol syntec (german variant) 0W-30. Stuck them both in the freezer for a day, pulled them out. No visible difference in viscosity.

Would the GTX you are using in this test happen to be the newer GF-4 API SM rated oil or the older GF-3 API SL oil?

The german castrol 0w30 is a very good product!....so you are an oil conessieur like me eh?:p

I'm not sure, the GTX bottle is at my parents house which i don't have immediate access to. I can update later if need be.

Yeah, german syntec is supposed to be a true competitor to mobil 1, unlike castrol's previous half baked "synthetics". Unfortunately, my current car specs 20 weight, last i checked GC doesn't come in 20 weights. So it's just mobil 1 0w-20 these days, which i have like $100 worth of mobil 1 sitting around. 30W is supposed to be fine also but thicker oil means slightly less HP, no sense in going out of my way and out of spec to decrease my HP. :p
 

OS

Lifer
Oct 11, 1999
15,581
1
76
Originally posted by: Eli
Originally posted by: OS
Originally posted by: cavemanmoron
I recall a test for Mobil 1 they put it,and soem other non-synthetic oil in a Cold freezer,
like -30f if I recall correctly,and the non-synthetic oil was like Molasses,the Mobil 1 was pourable.

I have vials of oil, castrol GTX 5W-30 and castrol syntec (german variant) 0W-30. Stuck them both in the freezer for a day, pulled them out. No visible difference in viscosity.
There is a huge difference between 32ºF and -30ºF as far as oil is concerned.

Yeah but my freezer doesn't do -30F. Might have to buy some dry ice sometime. It's just a casual test though, I don't live anywhere near alaska and 32F is already colder than my car will ever see.
 

mrrman

Diamond Member
Feb 8, 2004
8,497
3
0
I use Amsoil synthetic and noticed that my SUV is getting 200K(140 miles) more approx per tank. Its also a standard and I feel that the truck drives tighter not so loose any more. Also the oil change/filter frequency is much less. Every 25,000 miles I do complete oil change with filter and after that every 12,000 miles I just change out the filter and top it up. I use the Amsoil filter to. Next I will put synthetic oil in the tranny.
 

quentrm250

Golden Member
Nov 19, 2000
1,429
0
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In response to someone mentioning above not to use Fram filters:

I couldn't agree more!! Had one collapse on a brand new engine in the racecar which severely restricted oil flow. There's nothing more enjoyable than rebuilding a brand new engine the second time after only an hour or two of run time. ARGHHHHH!!
Collapsed oil filter = pull motor and replace bearings :(
 

TheLonelyPhoenix

Diamond Member
Feb 15, 2004
5,594
1
0
Just to second most of what's already been said...

As long as your car is relatively new, and you intend on sticking to synthetic oil for the rest of the car's lifetime, go for it.
 

Vegito

Diamond Member
Oct 16, 1999
8,329
0
0
Originally posted by: JulesMaximus
Originally posted by: AkumaX
Do you use synthetic? Do you use both? Do you switch back and forth between changes? Do you use one at higher mileage than another?

I'm at 90k and thinking of using Mobil 1 Synthetic 5W30 (cheap deal in HD), but does that mean I have to use synthetic from now on?

Waste of money. Just stick with whatever the manufacturer recommends for your car and change it every 3k miles.

right but if ur 911/corvetts comes off the line with mobil1 then it's not a rip off

those those enzo oil cost like 65/quart

EDIT:
C&D:
That, and Pentagon-size maintenance bills. On the trip back from the track, Rapp complained that the Enzo?s special Shell Helix 10W-60 synthetic oil, of which the V-12 requires 12.2 quarts, runs him $60 per quart. If a $732 oil change sounds criminal, consider that the factory won?t warrant the engine if you don?t use the oil and estimates the replacement bill at $200,000.