Would you even bother with Syn????

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k2xj

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Here's the story...1993 Toyota Tercel, 1.5L 4Cyl, about 80,000 miles. It is currently used on mostly short trips as my wife is on maternaty leave but come the new year will be back to dealing with a 35 mile hwy commute one way.

Currently the engine looks pretty sludgey (if thats a word). Previous owner obviously didnt take too good of care.

Would you even bother with synthetic in this rig or just stick with some good quality dino (GTX or possibly Castrol HM)?

Your opinions are appriciated.
 
Sure why not? Just run a double dose of AutoRx with appropriate rinse cycles. When the young engine is clean, then switch over to synthetic oil and lengthen the OCI for that commute.
 
There are likely other choices, but I would suggest you consider Mobil Clean 5000. The low flash point indicates a conventional oil, and they claim to have extra detergents. Should be a good combination to keep the engine running well and clean it up over time. Not sure with an engine of that age you will get your $$ back with a synthetic.

Contrary to popular belief, synthetics (III & IV) do not naturally make for a clean engine. They are worse than conventional oils because they have a lower solvency, and you depend on the blender putting in the right combination of additives to make up for it.
 
Quote:

PetroCan Supreme...hadnt even thought of that...high quality???

Click to expand...


You will get other opinions on that, especially from those south of 49, who don't appreciate the size and capability of Petrocan. Not sure what grade you are looking at, but I think in the 5w20 grade the Petrocan Supreme is the best on the market including the synthetics and the blends. See my thread currently on page 2 titled something like 5w20 Synthetics - What Value? Near the end I've updated the spec sheets.

However, if your objective is to clean the engine, I have the unpopular belief that a cheap oil will do that best. This is because a cheap (lower base #) oil has more volatiles (lower flash point) and thus more soluble components which dissolve sludge better.

If you want to do a temporary thing to clean the engine, another possible candidate is Esso Extra. It looks almost identical to Mobil 5000 which I'm not even sure we can buy in Canada. The Mobil version seems to use a pour point depressor to excess, but other than that they share the same low flash point.

The PC Supreme is a higher quality oil with a higher flash point and as a result may not have the same cleaning ability as the Esso Extra or Mobil 5000.

Just my thoughts - which upset a lot of the "good old boys" here
stirthepot.gif
!
 
Ron, You have a hat full of unproven theories!

Quote:

This is because a cheap (lower base #) oil has more volatiles (lower flash point) and thus more soluble components which dissolve sludge better.

Click to expand...



Point #1 -

Group I solvent refined base oils have higher natural solvency as a property, but the bare base oil run in a car engine will generate new sludge/deposits faster than it can dissolve existing ones.

Again, please actually look at the pictures in This Lube Reports Article .

This is sludge generated by running SA oil with out detergent additives.

SA oils are typically the lowest cost Grp I oils. Why can't this Grp I oil keep itself clean?

Point #2 -

The GF-4 qualification requires passing the Sequence IIIG test, which is 100 hrs at 3600 rpm & 150C(300F) degrees. Since this is a severe test, up to 4.6L of make-up oil can be added.

At the conclusion of the test, the pistons are removed from the engine and the weight of the varnish & deposits is measured.

Guess why an all Grp I based 5W-20 or 5W-30 is not run in the Sequence IIIG?

Because it can't handle the high temperatures, let alone try & keep itself clean!

So, consider all the properties of a Grp I base oil before you start making a recommendation.
 
Blue99,

I've concluded that you may know as much or more about oils than anyone else I have seen posting here. I suspect you are deeply into the business and it rates more than the hobby status I have the time for.

However, I think you exaggerate my points. I recommended a ESSO Extra or a Mobil 5000 oil over a synthetic. I don't think either is a group I oil. In fact I don't even know where to buy a group I oil.

An API SA oil has NO ADDITIVES by API definition. I have never recommended an SA, and in fact posted the same war story pics of the SA oil article. Obviously a very bad choice.

My point is that a good Group II with the proper additives (SM qualified) will likely give a cleaner engine than a synthetic. A Group I would also with good additives, but I suspect you would not meet the 15% Noack of SM with only Group I.

Further a poorer Group II with good additives may also do even better because of the low FP (and I would suggest the Mobil 5000 and ESSO Extra are in that category).

I would suggest that many here don't appreciate that synthetics are prone to sludge and varnish formation.

As per my other post, if you can provide facts which dispute this, I'm happy to listen and debate.
 
A dirty engine like this can benefit the most from the added solvency/detergency of a high TBN, PAO/Ester synthetic. In fact, you'll see improved performance simply from cleaning out some of the sludge and varnish from using conventional lubricants.

I'd switch to Mobil 1 (or even better Delvac 1) with a couple of short drain intervals of say 8000km to clean out pre-existing deposits from the conventional oil. The OEM Toyota oil filters are of decent quality, so I'd recommend those.

Once you have the engine clean you can increase the service interval if you feel comfortable doing so. A oil/filter change interval of 12,000km/6 months using any top tier synthetic is conservative.

As an aside, the market share of Group I, solvent refined basestocks has dropped significantly over the past five years. The next API specs for gas/diesel engines will use even less of them, in favor of Group II+ oils and synthetic blends. In fact, I would not be surprised if the upcoming "GF-5" gas engine specs can only be met by synthetic blends or above.

TS
 
personally, I wouldn't bother with syn in a 13 yr old sludgy engine. I would definitely auto-rx it to clean it and use dino. what's the useful life on this car? 3-4 years. with the possiblity of leaks, I wouldn't do it but that's me. I'm not a big risk taker plus I had bad experiences in the past.
 
I had a similar situation with a 1987 Sentra that had been neglected by my mother-in-law. We received the car when she died and it had some significant engine problems-smoking, stuck rings, etc. A couple courses of AutoRX made a world of difference. Smoking was gone, power was back, etc. After that I drove it for nearly a year/15K miles before selling it. I still see it on the road today.

In an engine that old I wouldn't bother with synthetic though. The Sentra did just fine on a decent conventional oil.
 
Ron

It goes both ways. Since you were the first to claim syns won't keep an engine as clean as dinos do, and since most people in this forum believe the opposite, I believe that puts the burden of proof on you.
 
Quote:

Contrary to popular belief, synthetics (III & IV) do not naturally make for a clean engine. They are worse than conventional oils because they have a lower solvency, and you depend on the blender putting in the right combination of additives to make up for it.

Click to expand...


What about Redline?

Quote:

5 years old with ~ 70K on the clock.
RedLine since the 10K mile mark until present.

Click to expand...

FirstpictureswithValveCoverOff025.jpg


redline thread


Also, show me two engines, one ran with GIII or GIV and the other with dino, following manufacturer OCIs and we'll see which one's cleaner.
popcorn.gif
 
In BC try Chevron dino with short OCI and or an ARX.
A sludgey corolla usually just means the owner used long OCI and didn't add oil when needed.
Oil Maintenance is usually a good shorthand for all maintenance so I'd either be looking at actual services records if in the car or you know where it was services
or be going down the list of 90K changes
coolant
trannie
pcv, grommet and hose
It's last smog test may show
other items to inspect
plugs , cap, wires
air filter
switch to the longer filter if it'll fit in there
like the purolator 14477 instead of 14476 to catch more sludge while cleaning
 
Quote:

Ron, It goes both ways. Since you were the first to claim syns won't keep an engine as clean as dinos do, and since most people in this forum believe the opposite, I believe that puts the burden of proof on you.

Click to expand...


You are right. Groupthink is tough to change. Let me try and word it another way. I would suggest higher # group oils tend to prevent the formation of high temperature sludge better, due to their higher oxidation resistance (there is little doubt about this). If you have a look at various base oils (including the Petrocan one) at the link below you will see that Chevron's rating of sludge control essentially tracks oxidation resistance. However, I would venture that it is not quite that simple. There are issues with low temperature sludge as well and in fact ILSAC has tests (finished oil) for low temperature sludge and varnish resistance, unrelated to oxidation resistance. So if you form sludge what then is important?

I would suggest solvency of the base oil. Check the link again and you will find that group I is the best and IV the poorest. And although this chart does not show it, there is a difference between group II and III as well.

So if you are changing oil often, with a moderate amount of sludge formation and high solvency oil it keeps going out with each oil change and thus a nice clean engine. On the other hand if you use very extended oil changes, with little high temperature sludge formation, but still some low temperature sludge and poor solvency guess what can happen? Potentially clean oil and dirty engine!

Solution? Dump in some of the nasty group I and let the high solvency clean it out - no need for that Auto-RX stuff. I suppose it is just an amazing coincidence that they happen to recommend you use conventional oil when you put in the RX.

If I'm not right, I hope at least to challenge some new thinking!!

http://www.chevron.com/products/prodserv/BaseOils/comp_light.shtml
 
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