Group III vs Group IV for higher mile vehicles

[remmious]

Ok here is something I been wondering about for a while. I read articles talking about changing synthetics for higher milage vehicles. Well in every article they talk about Group IV oils and how the Esters are extremely good cleaners and that if your vehicle hasn't been very well maintained that issues could arise. Well what about Group III 'synthetics'? If someone wants the benefits of a little better oil and cold weather starting can one assume it may be 'safer' to switch to a group III? I know they have cleaners/despersants but from training it doesn't sound like those compare to the clean power of Esters.

Am I correct in thinking this way? I would also assume these group III would also help reduce any further sludge build up and some claim to target sludge. Any thoughts are greatly appreciated.

 

[Lonnie]

Group III oils are very good. Don't expect an oil to clean an engine. A good oil will help keep a clean engine but can not be expected to make headway against a sludge problem. Even the best oil can't really keep up over the long run. Do a search on Auto-Rx for some good reading on catching up and keeping an engine clean. There is a lot of shared knowledge on this subject from Frank the Auto-Rx guy. If you want to delve into another class of oil try a search on the Super-Secret 5w-40. Do a search on Amsoil, too.

 

[Camu Mahubah]

I once owned an 82 Toyota pickup with 22R...the previous owner(s) were not what one would call mantainence hounds...the motor smoked, drank, and leaked like an old whale under constant stress from marksman who were most likely drunk themselves...She drank so much of my beloved Maxlife

that I had to resort to buying whatever was on sale...

Sludge and varnish are part of old age like wrinkles and clogged arteries...A Group III early in life would be like SPF 50 and low-fat diet in ones teens...if continued less problems over the long run...

 

[glenncof]

I recently put V. SynPower 20W50 (PAO per MSDS) in a 1985 911 with 183K miles which was on steady diet of GTX. This engine is known for leaks and I had a few drops before using it. It PAO'ed all over the cardboard under the engine and even dripped in parking lots.

The car is factory rated to consume 1qt/600miles and I have been adding Maxlike which appears to have solved the problem substantially.

My next test is GrpIII 10W40. I expect the GrpIII to leak less.

Oil cleaning ? My experience with doing many 1000 mile cleaning OCI's is yes. I can see the oil getting more clear when viewed with light as it drains. It seems like hydraulic lifter noise can be sometimes be eliminated.

Practically I would lean toward 'not' using expensive GrpIV with long OCI in high mileage app's. I prefer shorter OCI's to keep engine cleaner.

Of course there are exceptions.

 

[Pablo]

First of all "group IV" oils aren't esters (ester based oils are Group V).

Group IV oils are PAO based, most have some level of esters, but there are thousands and thousands of types of esters. Some are good cleaners, some aren't. Most used in conjunction with PAO oils are not there for "cleaning".

If your engine is dirty, use AutoRx.
If you want to use a good oil, pick a good oil.

 

[Triple_Se7en]

It would be nice to have info on the vehicle, mileage, age, and engine with this thread. That way, other owners of this particular vehicle could chime-in.

 

[remmious]

Quote:

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First of all "group IV" oils aren't esters (ester based oils are Group V).

Group IV oils are PAO based, most have some level of esters, but there are thousands and thousands of types of esters. Some are good cleaners, some aren't. Most used in conjunction with PAO oils are not there for "cleaning".

I was referring to the Ester co-base in PAO oils, sorry for the miscommunication. In my training it was still explained that these ester co-bases (typically Di-Ester or Polyol Ester from what I've seen) do a great deal of cleaning. They stated that this is the main reason people develop engine leaks on some vehicles. So that is kind of the driver to my questionl; when in doubt of maintenance (ex: buying a used vehicle) would one be safer to reach for a GrIII vs a GrIV or V I guess.

 

[remmious]

sorry I see my response got all jumble up with the quote. I wasn't asking about any particular vehicle just wanted to find out 'in general' or what 'rules of thumb' are out there.

Thanks for the replies!

 

[mitchcoyote]

Your assumption is correct. A grp3 would be less likely to cause a leak than a grp4/5... PP would serve you well at a good price....

 

[JAG]

I'd try a high mileage synthetic but realize problems could still occur. Forget thinking of this in terms of what you think the basestocks are made of...not only a dead-end road but also doesn't account for the additives.