Real Life performance differences between Grp III, IV, V?

[daemonite]

What are the real life differences between Grp III, Grp IV and Grp V oils?

Is there anyway you can actually feel a difference?
Do they clean better or is that the action of the add packs?
Do they last longer?

or...are they just about the same in performance but different in price?

I'm curious because 90% of the synthetics i see are grp III, just a couple are group IV or V.

 

[JohnBrowning]

How long do you want to own the vechile and what type of OCI would you like? Ester based lubes will keep an engine darn near spotless for the life of the vechile. PAO will do a good job in most applications up to 15,000 miles longer in some applications shorter in others. Group III I treat like like group I or II. It has some of the benifits of a GIV but not all of them. If you change your oil in the 3000-7000 miles area you will usualy be ok in most applications. The additivepackage determines how long you run oil in terms of protection.

In some applications insolubles are an issue and in these engines Esters rule and PAO is second. Group three would not hold up in an engine in terms of insolubles any better then most GII conventional oils!

Cold Temp and Hot Temp Viscoisty are the best with ester then PAO then GIII.

Solvency is best with Estewrs and then PAO and GIII are about tied.

Ester and PAO's are better at oxidation resistance then GIII but depending on the formulation base stock alone is not always the best indicator.

 

[pitzel]

The differences, IMHO, between the basestocks are only really seen on the extended drain side of things.

And even then, I think you have to get into the well over 20k mile range, in most engines, just to see the benefits of a PAO/Ester combo as opposed to a group III formulation.

 

[1911]

quote:

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Originally posted by daemonite:
What are the real life differences between Grp III, Grp IV and Grp V oils?

Is there anyway you can actually feel a difference?
Do they clean better or is that the action of the add packs?
Do they last longer?

or...are they just about the same in performance but different in price?

I'm curious because 90% of the synthetics i see are grp III, just a couple are group IV or V.

---

All's I know is that Texaco did some NYC taxi-cab fleet experiments some years back with post test engine teardowns. They found no statistically significant difference in wear but a definite difference in cleanliness/varnish/deposits. However, at least in these engines and OCIs (I do not know what these were), even the dino's would have made the engines last indefinitely. Thus I guess these tests perhaps demonstrated what is the general consensus of this board, that dino's in most engines with suitable OCI's will generally produce excellent results but perhaps with a little more varnish and deposits. However, perhaps for some engine type/driving style/desired OCI combinations, the use of synthetics could potentially be very beneficial.

I also heard that Consumer Reports (although I don't have a lot of respect for them)did some tests too and found no real wear difference. All this jives well with the used oil analysis posted on this board (assuming they are reasonably good indicators of wear which they may not be without invoking advanced techniques and particle counting).

1911