# Two older cars...switch to synthetic oil ?



## Guap0_ (Dec 2, 2017)

I wouldn't switch to synthetic oil. I'd add a quart of transmission fluid or marvel mystery oil first.


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## Bud9051 (Nov 11, 2015)

I,m not a pro on this but modern engine oils are far less inclined to turn to sludge. Once a year is a bit infrequent but your mileage looks very low on both vehicles. Just my wild guess but synthetic or blended might age better between changes, all-be-it at a cost. I wouldn't use the synthetic to stretch out the changes any farther than current.

We'll see what the pros have to say.

Bud


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## Bret86844 (Mar 16, 2016)

The only issue I've heard of with synthetics is you may get a bit of oil leakage. Something to do with being thinner and creeping through gaps regular oil is too thick to fit through. Your cars are low enough mileage though that I doubt it would be an issue though. 

Other than that, synthetics are superior in every way. I've run them in all my cars for years. Annual oil changes in my car and my wife's, same as you.


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## Gregsoldtruck79 (Dec 21, 2017)

Agree +1. No pro here, but LONG time, do my own car maintenance guy...

I have heard too many say that changed to syn after 70 K and they started getting small leaks from gaskets. And as mentioned, any time a big step is made to get sludge out fast, one takes a chance on clogging up the oil pick up tube or oil pump itself. 

I bought a 03 Jeep with a 4.0 engine with 78K miles on it. The engine had a top end "ticking" noise. I removed the valve cover and saw the whole top of the engine head and rocker arms were sludge city. 

So I just changed the oil every 1500 miles for 3 times and with each oil change, I topped it out with a half quart of Marvel Mystery oil , in with my Castrol 10W 30 GTX dino oil. 

After 5 K miles driven, the ticking noise stopped. For every oil change for the next 15K miles while using only the Castrol, the oil itself was still breaking up small bits of sludge that my oil filter was catching, which I could see when I dumped the OF in my used oil catch pan. . 

Today at 20K miles later and while still running the Castrol GTX dino oil, the top of the 4.0 L engine now, looks dandy clean. I do 3-4K mile oil changes, new Puralotor Plus oil filter every time at each oil change. O.K $$$$ wise to do for someone like me, that drives less than 10K a year. JMO


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## u3b3rg33k (Jul 17, 2018)

I use synthetic in everything at the first OCI. the 1940s farm tractor, the generator, my motorcycle, all the cars, the golf cart, lawnmowers etc. used synthetic makes decent chainsaw bar oil, too.

i'm basically at the point where all I buy is M1 0W40. enough anti-wear additives for the old engines, works well in winter, thick enough to keep my VANOS happy, has good UOAs.


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## Dave Sal (Dec 20, 2012)

Bud9051 said:


> Once a year is a bit infrequent but your mileage looks very low on both vehicles.
> 
> Bud



I bought my car new and it's now 18 years old. I had a company car when I was working so I didn't drive my personal car all that much. I average about 3500 miles per year and change my oil once every 12 months or 5k miles, which ever comes first. The 12 months always comes first. :smile:
Been using full synthetic oil from day one. Not a trace of sludge as noted when I changed the valve cover gasket.


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## Dave Sal (Dec 20, 2012)

u3b3rg33k said:


> thick enough to keep my VANOS happy, has good UOAs.



BMW owner identified. :biggrin2:


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## sestivers (Aug 10, 2007)

Oil degrades with time in addition to mileage. Regardless of how few miles it has been, you shouldn't go longer than three months between oil changes with conventional or longer than six months with synthetic.


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## u3b3rg33k (Jul 17, 2018)

Dave Sal said:


> BMW owner identified. :biggrin2:


if I said it makes me happy when VTEC kicks in, who would I be


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## u3b3rg33k (Jul 17, 2018)

sestivers said:


> Oil degrades with time in addition to mileage. Regardless of how few miles it has been, you shouldn't go longer than three months between oil changes with conventional or longer than six months with synthetic.


oil company (Mobil) says 1 year or mileage, whichever comes first. I've been doing 15-17k OCIs with UOAs that say i'm doing just fine. time doesn't degrade modern oil very fast.


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## Brainbucket (Mar 30, 2015)

Rule of thumb. You can go from synthetic to dino oil but you can't go from dino oil to synthetic. Reason is synthetic 'washes' the engine and dino oil doesn't. Hence the sludge or oil build up if you will that will be washed off the engine surface. Now if the build up isn't bad, then go for it. But if it is, then you risk stopping up the sump screen or filter or oil ports. I built a 550hp 454 and used synthetic oil. after 50,000 miles of hard driving, I pulled it apart to freshen it up and I could see the hash marks on the cylinder walls. That would not have happened with dino oil. I would have had to bore it. Synthetic oil is amazing.:vs_cool:


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## Dave Sal (Dec 20, 2012)

u3b3rg33k said:


> if I said it makes me happy when VTEC kicks in, who would I be



Honda would be my first guess.


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## KHouse75 (May 14, 2008)

All myths.

You can change between regular and synthetic any time you want as many times you want no matter how many miles your vehicle has. Synthetic oil is not thinner than regular oil of the same weight. It's exactly the same viscosity. Synthetic will not was away all the sludge and clog up your pickup.


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## Guap0_ (Dec 2, 2017)

I don't see any reason to even try it. What is it going to do that is so wonderful?


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## KHouse75 (May 14, 2008)

Today's conventional oil is much better than the oil our parents and grandparents used. For most people, conventional is all you need. If you are driving in very hot conditions, do a lot of stop and go driving or do lots of towing, your vehicle will benefit from running synthetic.


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## mark sr (Jun 13, 2017)

> Synthetic will not was away all the sludge and clog up your pickup.


 Might be comparing apples to oranges but I've always heard that when tractors start using bio fuel it really cleans the system and clogs all the filters until the fuel system is clean and then you never have to change a filter again. No such correlation to synthetic oils ??


Whenever I buy a vehicle that's been poorly maintained I'll change the oil more often in the beginning, sometimes adding some kerosene or transmission fluid shortly before changing the oil to help clean it.


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## Bigplanz (Apr 10, 2009)

Guap0_ said:


> I don't see any reason to even try it. What is it going to do that is so wonderful?


Any naturally aspirated engine will run fine on conventional oil. Just change it every 3K miles. Turbo or supercharged engine, go synthetic.

My 5.4L Navigator gets conventional oil. If I had a new Navigator with the V-6 turbo, it would get synthetic.


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## u3b3rg33k (Jul 17, 2018)

Bigplanz said:


> *Any naturally aspirated engine will run fine on conventional oil.* Just change it every 3K miles. Turbo or supercharged engine, go synthetic.
> 
> My 5.4L Navigator gets conventional oil. If I had a new Navigator with the V-6 turbo, it would get synthetic.


that's a huge claim. my NA engine specifically calls for synthetic oil.


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## Gregsoldtruck79 (Dec 21, 2017)

My best friend that used to build engines in to high performance engines, told me about the dino vs. synthetic oil debate when I asked him would it help my engine, that was NOT specified in the owners manual, to run synthetic oil in it. He told me it would not hurt, but that I would not see any big difference in it until cash payout time as the synthetic oils cost more. 

He told me the newer engines where the manufacturer specified synthetic oil to be used, need synthetic oil. Because their machined parts have MUCH tighter fitting machined tolerances. Whereas,our older dino oil engines, had less tight crankshaft/camshaft etc. bearing tolerances. 

The newer engines are requiring a oil that will flow thinner to get in between the closer machined parts, have better friction reduction characteristics while operating under higher operating temperatures. Synthetic oils filled the bill for this need. Just my understanding of the debate anyway.


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## u3b3rg33k (Jul 17, 2018)

My favorite synthetic oil is $5/qt. i don't consider that expensive when I only have to change the oil once a year.


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## Bigplanz (Apr 10, 2009)

u3b3rg33k said:


> that's a huge claim. my NA engine specifically calls for synthetic oil.


As in all things Internet, that's just my opinion. My Navigator is 18 years old. If my owner's manual stated use synthetic, then that's what I would do.


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## u3b3rg33k (Jul 17, 2018)

Bigplanz said:


> As in all things Internet, that's just my opinion. My Navigator is 18 years old. If my owner's manual stated use synthetic, then that's what I would do.


that's the problem with owners manuals. oil technology advances, Ford doesn't revise and re-publish 18 year old owners manuals. 

A manual may call for 10W30, where a modern 5W30 provides superior cold start/flow and wear protection.


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## Bigplanz (Apr 10, 2009)

u3b3rg33k said:


> that's the problem with owners manuals. oil technology advances, Ford doesn't revise and re-publish 18 year old owners manuals.
> 
> A manual may call for 10W30, where a modern 5W30 provides superior cold start/flow and wear protection.


Actually, my Nav was specced for 5W30 when it was built, then the spec was revised to 5W20, for MPG reasons. Ford mechanic friend of mine said, if you push it hard, tow a lot, use 5W30. Like I said, if the manfacturer specifies synthetic, that's what I would use. I put 5W20 conventional oil in mine.


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## Gregsoldtruck79 (Dec 21, 2017)

I am noticing on my auto parts stores oil display shelves, the selection of 5w/30, 10w/30, 10w40, straight 30w non-synthetic oils are not getting stocked so heavily in volume like they used to be.

I cannot help to think the oil sales industry may be figuring on the vehicles needing these oils, are not long from being in the recycle piles. And the shelves will become all stocked with synthetic oil. Maybe, maybe not....


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## SeniorSitizen (Sep 10, 2012)

Gregsoldtruck79 said:


> He told me the newer engines where the manufacturer specified synthetic oil to be used, need synthetic oil. Because their machined parts have MUCH tighter fitting machined tolerances. Whereas,our older dino oil engines, had less tight crankshaft/camshaft etc. bearing tolerances.


I read this " tighter fitting tolerances " often but those writing or stating that don't seem to ever give any numbers. I assume we're talking about production engines and not engines that are torn down after every race and sometimes before the race ends.:biggrin2:


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## Brainbucket (Mar 30, 2015)

It's really not the tighter tolerances but the "holes" that the oil flows through. I have been building engines since the 70's and yes professionally. It's what I do for a living for the last 40 years as an ASE Recertified Master Auto Tech. Right now I'm building a L99 into a LS3 with 750 hp. I remember the Sherriff's department motor pool that was blowing up their engines at around 40,000 to 50,000 miles in the Crown Vics they had. They were use to putting in 20w-50 into their older cars. The 4.6 doesn't like that. The oil was too thick the travel through the small holes designed for 5w-20, thus starving the oil journals. And YES, synthetic oils WASH your engine. Pull one apart that has been running dino oil and one with synthetic and the difference is amazing. Dino oil is all gunky and sludge. The synthetic oil engine will be nice and clean. Night and day difference. :vs_cool:


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## ron45 (Feb 25, 2014)

This question has been played out so much.

If the oil meets the standards put forward.?


It's your money.

Even the cheapest oil on the shelf meets the standard. If not the store owner is going to have problems.

I always use the store brand ( cheap) oil and only change the oil every, give or take 30,000 miles.


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## u3b3rg33k (Jul 17, 2018)

ron45 said:


> This question has been played out so much.
> 
> If the oil meets the standards put forward.?
> 
> ...


That's not true at all. manufacturers have lists of specifications that many super cheap off-the-shelf oils do not meet. usually the approvals are listed on the oil containers.


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## Bigplanz (Apr 10, 2009)

u3b3rg33k said:


> That's not true at all. manufacturers have lists of specifications that many super cheap off-the-shelf oils do not meet. usually the approvals are listed on the oil containers.


If it meets API SN standards, it is fine. Synthetic is better, sure. More important is viscosity, as variable cam and variable oil pumps need the proper viscosity oil. If it calls for 0W-20, don't use anything other than that. I had a 1970 Impala that was using 20W-50 before it got scrapped. No way I would put that in a modern car.


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## u3b3rg33k (Jul 17, 2018)

Bigplanz said:


> If it meets API SN standards, it is fine. Synthetic is better, sure. More important is viscosity, as variable cam and variable oil pumps need the proper viscosity oil. *If it calls for 0W-20, don't use anything other than that.* I had a 1970 Impala that was using 20W-50 before it got scrapped. No way I would put that in a modern car.


that's also not right - the manufacturer provides oil weight recommendation based on environment (how cold will it get) and how hard you work the engine (i.e. how hot the oil will be). the oil needs to be as thin as possible when cold, while still being thick enough to provide protection while at operating temperature. as of yet there is no oil that is adequately thin when cold while necessarily meeting the performance requirements at operating temp. 

separately, is the additive package. just because your engine calls for 0w20 doesn't mean any 0w20 is adequate. I am able to use either m1 15w50 or 0w40 in my motorcycle because they both have adequate protection for my valvetrain. I prefer the 0W oil as I often start out on cold mornings and the difference in cranking is quite noticeable. 

if you want compare viscosity, look at the cSt numbers, not the consumer friendly weights. Ideally, the -40C, 40C, 100C and 140C numbers would all be identical. that oil is still a tribologists wet dream.


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## ron45 (Feb 25, 2014)

What is better.

The Ford or Chevy.?

In the mean time here comes Genie in her new Dodge.


Do you think they will make it to the prom.?


One has oil worth $100 a quart.
The others have just store brand oil.

The oil better not be on the shelves if it doesn't meet today's standards.


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## u3b3rg33k (Jul 17, 2018)

ron45 said:


> What is better.
> 
> The Ford or Chevy.?
> 
> ...


cost is a straw man. excellent synthetic oil can be had for $5/qt. 
Even redline oil is under $10/qt and they will supply you written approvals for API SN, BMW LL-01, Mercedes Benz-Approval 229.5, Porsche A40 and VW/Audi 505.00/502.00, ACEA A3/B4-12, Mercedes Benz 229.3/226.5, Renault RN0700/RN0710 and PSA B71 2296 on request. 

what you're really getting with good oil is a stable viscosity index over a wide temperature range, that doesn't shear down like a mineral oil does over time or wax up in storage. anti-wear additives and adhesion to engine parts on top of that. is that in the store brand oil? hard to say. maybe it's rebranded Redline. maybe it's new old stock. both will get you to prom. the latter won't get you lasting protection.


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## Bigplanz (Apr 10, 2009)

u3b3rg33k said:


> cost is a straw man. excellent synthetic oil can be had for $5/qt.
> Even redline oil is under $10/qt and they will supply you written approvals for API SN, BMW LL-01, Mercedes Benz-Approval 229.5, Porsche A40 and VW/Audi 505.00/502.00, ACEA A3/B4-12, Mercedes Benz 229.3/226.5, Renault RN0700/RN0710 and PSA B71 2296 on request.
> 
> what you're really getting with good oil is a stable viscosity index over a wide temperature range, that doesn't shear down like a mineral oil does over time or wax up in storage. anti-wear additives and adhesion to engine parts on top of that. is that in the store brand oil? hard to say. maybe it's rebranded Redline. maybe it's new old stock. both will get you to prom. the latter won't get you lasting protection.


It's all good. Everybody can make their own choice. BB builds huge, high HP engines. Synthetic is the answer. Me, I have a 5.4L that never leaves a paved road and never tows anything. Just use the oil you want! 

It's all good.


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