Group III vs Group IV oil?

[mortimersnerd]

Been doing some research into synthetic oils and am looking for a little feedback. Anyone know enough about oil to discuss the advantages of going to a full Group IV oil (truly synthetic) over a Group III (hydrocracked from a petroleum base-not truly synthetic) despite the significant additional cost? Any suggestion about good oils to go with and where to purchase? My inclination is to go with a full Group IV because I'm pointlessly anal about this kind of stuff, but I'm having a hard time finding out which oils are actual Group IV due to the massive amount of marketing hype around synthetic oils. If it matters, I'll probably continue to change oil around 5-7k miles to reduce any potential warranty problems, as my MS3 is only about 11k old. Thanks!

 

[KellyJoe]

Go to bobistheoilguy . com to find out probably anything you need to know about oil. I used to be an Amsoil dealer and my opinion is that if you plan to stay with that change interval you mentioned, either group will suit your needs just fine.

 

[MSMS3]

Turbochargers live in extremely hostile, high heat conditions. There is an oil line bathing the turbo shaft journal in oil to help cool down the heat (along with a water jacket in the turbo housing). Full synthetic oils simply perform better in the extreme heat of a turbocharger and have a lower chance of breaking down into solids (coking).

So, it's cheap insurance in the long run to spend a few extra bucks per oil change for full synthetics.

However, bear in mind that the additives, especially those that provide detergent protection and that control viscosity variability with temperature, do break down long before the oil itself. So long oil change intervals (beyond 7500 miles) are going to exceed the life of many of those additives.

Each to his own, but I run full synthetic and try to change every 5-6K miles.

 

[byau]

Turbochargers live in extremely hostile, high heat conditions. There is an oil line bathing the turbo shaft journal in oil to help cool down the heat (along with a water jacket in the turbo housing). Full synthetic oils simply perform better in the extreme heat of a turbocharger and have a lower chance of breaking down into solids (coking).

So, it's cheap insurance in the long run to spend a few extra bucks per oil change for full synthetics.

However, bear in mind that the additives, especially those that provide detergent protection and that control viscosity variability with temperature, do break down long before the oil itself. So long oil change intervals (beyond 7500 miles) are going to exceed the life of many of those additives.

Each to his own, but I run full synthetic and try to change every 5-6K miles.

Group III and IV are both considered full synthetic...I think you missed the OPs intent. From what I know, most of the oil you can buy off the shelf will be group III. Don't quote me on this but I believe Mobil 1 is group III, and Mobil 1 Extended performance is possibly group IV (again, just a guess).

Personally I just run Pennzoil Platnium which is just a plain group III synthetic.

 

[Super Unique]

You will do just fine changing every 3 to 4 k with a regular cheaper organic oil. For people not changing it on their own, synthetic adds a HUGE amount of cost to each oil change, and is NOT worth it for most drivers.

 

[MSMS3]

Group III and IV are both considered full synthetic...I think you missed the OPs intent. From what I know, most of the oil you can buy off the shelf will be group III. Don't quote me on this but I believe Mobil 1 is group III, and Mobil 1 Extended performance is possibly group IV (again, just a guess).

Personally I just run Pennzoil Platnium which is just a plain group III synthetic.

Sorry to disagree, but I stand by my position that group III oils are, at best semi-synthetics with no more that 10-25% pure synthetic (PAO) oil. Any oil mfg web site will confirm this. Check Mobil, for example.

And oils that are mostly dyno based, even with some synthetic component, simply will not withstand heat as well as pure synthetic.

Mobil 1 is Group IV with only PAO in its base stock.

I'm not saying that a 100% PAO base stock oil is necessary. I am saying that such Group IV oils are superior in protecting in extreme heat situations that turbocharged engines face. I'll pay a few extra bucks per quart for that protection.

 

[byau]

I'm not here to argue whether group IV or III is better, they're all good. Hopefully you're not buying Mobil 1 thinking you're getting a group IV oil. Mobil 1 is great, I have two 5 qt jugs in my garage along with a few PP waiting to be used (I stock up when they're on sale). That whole "Castrol" thing a few years ago basically changed companies labeling as "full synthetic" since group III base stock could be classified as such.

quick read:
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1439860

 

[MSMS3]

So, Im supposed to take as gospel the back and forth discussion of guys just like us on another forum as to the percentage content of PAO in Mobil 1's base stock?

Sorry, but it is clear from Mobil that ALL the base stock in Mobil 1 is PAO. All of it.

http://www.mobil.com/Australia-English/LCW/Audiences/Synthetic_V_Mineral.asp

Now every Group IV oil must have a small amount of non PAO mineral oil in the additives because they will not emulsify in pure synthetic.

But it is abundantly clear from the industry, rather than from those who talk about the industry in user forums, that Mobil 1 is Group IV, and Group IV must be 100% PAO in the base stock itself.

If someone can show me that Mobil 1 is not 100% PAO in its base stock itself, I want to know where is the proof, and not from a bunch of members of a usergroup talking amongst themselves.

 

[ericrapp]

Are the advantages of the group four based on lifespan or heat ranges, or even engine tolerances?

 

[Super Unique]

I will assert that group III and group IV are equally better than organic oil for purposes of enduring heat. That is a given. From a semantics point of view group IV is clearly superior to group III.

All these takes a serious back seat to a vendors choices in additive packaging. It also is important to consider the application of an oil. tractor vs. turbo car is a very different environment to operate in.

Customer needs are also a factor.

If you change your own oil every time, then it is definitely worthwhile to figure out a synthetic that gets along well with the speed3. If you go to a garage or quick lube for oil changes then it is a completely different situation.

Personally I don't like dealing with oil changes on my speed 3 due to the low stance of the car and the plastic pan to drop, the cartridge filter etc.. I find to be a real pain in the ass. Therefore I go to a local place that has a quality regular organic oil and get it changed every 3 to 4 thousand miles and / or once a month. Under this schedule a decent organic oil is perfectly fine to use. The whole point of synthetics are for higher heat and longer use.

Just paying attention to your oil level and changing every time it's due without going way over the limit, your taking better care of your car than 90% of the other drivers on the road.