Synthetic oil snafus

[Tom NJ]

Originally Posted By: Solarent
Is it therefore fair to say (IMO) that a Conventional Oil with a additive package designed to prevent and clean existing deposits (I am thinking of Pennzoil here) COULD give performance in this regard equal to or better than a random off the shelf Synthetic Oil IF in that specific oil a less robust additive package overrides the nature of the synthetic base as you indicated? (Only in the area of deposit formation and cleaning - all other factors being equal)

And would it be fair to say that the natural characteristics of Synthetic Oils allow formulators more flexibility in terms of Multi-grade viscosities, enhanced thermal stability etc? Providing they use the right additive enhancements?


Yes synthetic base oils offer the formulator the ability to make a really superior oil. I believe most take advantage of that opportunity, but not all. Some may drop a minimal additive package that just skinnies-by the specs into a lower grade Group III just to call it synthetic and maximize the profit. The claimed specifications and approvals are a better guide than the marketing type performance claims on the label and literature. Paper never refused ink.

Tom NJ

 

[Bryanccfshr]

:rollseyes: People need to read and use an oil that meets your autos makers recomendations and stay within their mileage recomendations. In most cases conventional oils serve admirable, in other cases a synthetic is required. This in some cases extends the recomeneded OCI, while if conventionals are used the OCI is kept shorter(see Toyotas 0w20/5w50 substition clause)
I was only able to tolerate half of the first page of this.

 

[Capa]

Originally Posted By: Tom NJ
Originally Posted By: gfh77665
"Are dinos perfectly equivalent to synthetics?" As it pertains to Longer OCI? and Cleaner engines?


There are two ways an oil can contribute to a "cleaner engine": the oil may prevent deposits, or the oil may actively dissolve and disperse existing deposits. In both cases, the additives, including detergents, dispersants, and anti-oxidants, play a much larger role than the base oil.

A synthetic base oil may contribute to preventing deposits by nature of its better oxidative stability, assuming it also has a solid additive system. A weak additive system can override the effects of the synthetic base oil in this regard, so the fact that the oil is "synthetic" is not a guarantee it will be better at preventing deposits. In fact, under some conditions, such as thin oil films at very high temperatures, non-polar synthetics like PAO and Group III are actually more prone to forming deposits because of their inability to dissolve deposit precursors. While these conditions are rare in automotive engines, they do preclude the use of PAO and Group III in certain applications such as jet engines, reciprocating air compressors, and oven chain lubricants.

With respect to the base oil's abiliy to clean existing deposits, polarity is the key factor. Conventional Group I base oils are much more polar than synthetic PAOs and Group IIIs and may clean better provided they are robustly inhibited for oxidation. Most are not, however, since anti-oxidants are expensive, so the lower oxidative stability of Group I base oils often overrides their better dissolving power. Non-polar synthetic base oils like PAO and Group III contribute nothing in and of themselves to cleaning existing deposits. That said, such synthetic oils often contain a more robust additive system since they usually represent an oil company's flagship product or "best foot forward."

The only synthetic base oils that both prevents deposits and cleans existing deposits are esters (and to a lesser degree alkylated naphthalenes), but these are so expensive that they are rarely used in engine oils in a meaningful dosage.

Regarding extended OCIs, synthetic oils have the capacity to contribute significantly to longer OCIs through their better oxidative stability, provided once again that they have a robust additive system. A weak or mediocre additive system can neutralize the benefits of the synthetic base oil and the finished oil may offer no OCI extension at all, even though it is "synthetic".

It is important to understand that many if not most marketers of synthetic oils do employ a more robust additive system since this oil is their top shelf offering and often utilizes their best technology. Since they have to put more money into the base oils and can sell it at synthetic prices, why not invest more in the additive package as well. This is especially true with very expensive base oils such as PAO and Group III+. It's not a sure thing, but the probability is higher that synthetic oils have both better base oils and better additive systems, and therefore may be both cleaner and extend OCIs.

So, the definitive answer to your question "Are dinos perfectly equivalent to synthetics as it pertains to Longer OCI and Cleaner engines?" is absolutely YES....and NO. Or to be more concise, it depends!

Tom NJ


Tom,
Many thanks for taking the time to respond to this thread. Your posts are always meaningful and full of details as well as accurate.

 

[Jarlaxle]

Originally Posted By: BullyT
The manual for my BMW 7-Series is very specific that only synthetic oil should be used, and an "approved long-life" oil at that. Based on my oil life monitor I could change the oil every 25,000 km (15,000 miles) but I change it at 15,000 km. The car now has 330,000 km on it and the engine is a smooth as ever and burns no oil. Inspection when I had the oil pump checked showed an exceptionally clean engine.

I have not heard of sludge build up in a vehicle where synthetic oil has been used. I'm not saying it doesn't happen--just saying that I haven't heard of it.

I put synthetic oil through my own unplanned torture test. My wife had a brain tumour removed two years ago, and several days later she collapsed at home. I got a panic call from our daughter and headed home while my daughter called 911. On my way home, in rush hour, my water pump seized on the highway and I lost all coolant. I pulled over but was on an out of town stretch of highway and I figured it would take an hour or more for a tow vehicle to arrive. I called my daughter, and the paramedics were at my house and transferring my wife to an ambulance. My daughter was 15 at the time and obviously frantic. I decided that the BMW engine was "only money" and drove the car over 15 miles with no coolant, no fan belt, no fan...nothing. Temp gauge was off the scale. Went straight to the hospital. Fortunately my wife's condition was only due to low blood pressure due to the surgery. The next day I got my BMW to a good local mechanic who checked everything over. He had to replace the cooling components (water pump, fan belt, fan) but the engine was running perfectly. No blown headgasket...no coolant in the oil. The mechanic said "these things hold 8 litres of synthetic oil...that's probably saved your engine". Not a scientific explanation...nothing more than an opinion really...but I do believe synthetic oil provides an extra margin of protection especially under extreme conditions. IMHO.


Don't the 7-series BMW's have coolant-loss protection, shutting down cylinders to prevent the engine from being damaged by coolant loss?

 

[Jarlaxle]

Originally Posted By: PZR2874
Originally Posted By: johnachak
I just don't get why someone would buy a vehicle with a small engine, then turbocharge it to get over 100BHP /l then complain it runs hot and beats up oil ( for instance, the Subarus with the blown turbos) Why not just buy the bigger naturally aspirated engine with like 80 BHP/l which will run forever and is easy on oil? I guess too fast too furious fever... I like engines to produce horsepower the old fashioned way... Big pistons...


Then why didn't you go with the CTS-V?

This is so ignorant I can't even comment about it.


Maybe because the V is about sixty grand?!

 

[Jarlaxle]

This won't be popular here, but: for 95% of the vehicles on the road, oil is oil. Synthetics are usually better...but it just doesn't matter, because regular oil is good enough.

When I see a Ford F-550 rollback wind up 920,000 miles on regular Pep Boys and Wal-Mart 15W-40 and regular ProLine and Motorcrafty filters changed at 5000 miles, I realize oil is oil.

When I see a Lincoln Town Car in livery service wind up 500,000+ miles (it's still running...about 570K, as I recall) on whatever bulk 5W-30 the company gets the cheapest, I realize that oil is oil.

 

[PZR2874]

Originally Posted By: Jarlaxle
Originally Posted By: PZR2874
Originally Posted By: johnachak
I just don't get why someone would buy a vehicle with a small engine, then turbocharge it to get over 100BHP /l then complain it runs hot and beats up oil ( for instance, the Subarus with the blown turbos) Why not just buy the bigger naturally aspirated engine with like 80 BHP/l which will run forever and is easy on oil? I guess too fast too furious fever... I like engines to produce horsepower the old fashioned way... Big pistons...


Then why didn't you go with the CTS-V?

This is so ignorant I can't even comment about it.


Maybe because the V is about sixty grand?!


That's the reason for me saying it. He didn't "get" why people buy small engines and charge them.... He likes making power the old fashioned way.... Big pistons.... Then bought a 6cyl Caddy

 

[Astro14]

Originally Posted By: johnachak
There is a thread on here, I lost it, but those who know how to get the most of the "Search" facility will find it. It has links to many 2003-2006 Subarus with blown Turbos do to a plugged screen that feeds oil to / from (I don't remember which) the turbo. I found it here in BITOG. The last entries were in 2011 I believe.
I guess this doesn't really belong here either... Sorry.


I'll go OT with you...the point is that the turbo engine is smaller and more fuel-efficient than the same HP NA engine...so the car can meet other design objectives like engine bay size. I've got over 150K on the OE turbo in the XC and over 128K on the OE turbo in the T5, so turbos can last a very long time.

Finally, my old Volvo turbo was the king of the mountain passes in the Rockies. (Turbocharging was developed for aircraft engines at altitude.) It would develop full boost up to about 12,000 feet. So, in the mountain passes, when a NA M3, or 'vette was making roughly 45% of its sea-level horsepower, my little shoebox was making 100% and could out accelerate both cars...in the mountains, I would only have a turbo.

 

[johnachak]

That 6 makes 304 hp with a naturally aspirated 3.6 liter engine. I said big pistons not many of them. The pistons in a 3.6l 6 cyl are pretty big. There are not too many larger 6 cylinder engines.A few yes, but they don't have a 4.3 available anymore in the car I want.

 

[johnachak]

Originally Posted By: Astro14


Finally, my old Volvo turbo was the king of the mountain passes in the Rockies. (Turbocharging was developed for aircraft engines at altitude.) It would develop full boost up to about 12,000 feet. So, in the mountain passes, when a NA M3, or 'vette was making roughly 45% of its sea-level horsepower, my little shoebox was making 100% and could out accelerate both cars...in the mountains, I would only have a turbo.


I don't live in the mountains so it was never a consideration for me. I'm glad you are able to get that kind of life from those turbo'ed engines. I never knew anyone with a Volvo turbo. Just curious, Syn or Dino?

 

[SteveSRT8]

Originally Posted By: johnachak
That 6 makes 304 hp with a naturally aspirated 3.6 liter engine. I said big pistons not many of them. The pistons in a 3.6l 6 cyl are pretty big. There are not too many larger 6 cylinder engines.A few yes, but they don't have a 4.3 available anymore in the car I want.


Even though I own 2 blown engines I still love N/A motors the best.

It's been my experience that they easily outlast the average boosted engine, and I just love a nice peaky power curve with that smooth rush up the rpm range that only N/A has. That's another reason we like V8's around here, not a single small displacement motor in our stable anymore.

I'm sure if I lived in the Rockies I'd feel different!

 

[Jarlaxle]

Quote:
Even though I own 2 blown engines I still love N/A motors the best.

It's been my experience that they easily outlast the average boosted engine


My old Shelby Charger had over 260,000 miles on its original 2.2 turbo when sold...ran perfectly. Far as I know, still the original turbo.

My friend's Dodge Caravan turbo was hit with 290,000 miles...internally-untouched engine except for timing belts.

 

[SteveSRT8]

Yeah, and for every one of those old stories I can show you a new contemporary turbo car that is trashed.

3 different Subarus in the last few years come to mind that I knew personally.

It may not be typical, as many of the cars I am familiar with are tweaked a bit by the owners, but IME they blow up a bit more than I could tolerate! I'm sure the overwhelming majority of turbo cars are just fine in normal use.

Now my mechanically supercharged 572 BBC in a go-fast boat is a different story, but it was carefully prepped by my third generation machinist BIL who is the man when it comes to ultra precise work. No problems there, but once again hardly typical.

 

[Bill in Utah]

going to lock this up since its run its course and the last few posts are off topic.