What's behind the HTO-06 specification?

[tig1]

Max Wander,
Do you have a turbo Honda? If so my advise would be to call Honda and discuss your concerns with them. No one here can look into the minds of Honda engineers, but knowing Honda they probably have good reason for the HTO spec.

 

[parreda]

PP or M1 and be done

 

[JAG]

Originally Posted By: Max_Wander
Originally Posted By: JAG
Originally Posted By: Max_Wander
it just looks to me like Honda/Acura just arbitrarily chose a test based on a characteristic where Mobil1 stands out, in this case volatility and burn off. Then they made up a spec that singled out only the characteristic of their marketing partner, ExxonMobil's product and put it up against clearly inferior nameless competitor products.

The test focuses on turbocharger deposits, not volatility and burn-off. Honda came out with the spec. for their turbocharged engines and did not feel comfortable with recommending just ILSAC GF-4 or API SM specs.


I see. How are volatility and burnoff not related to turbocharger oil coking?

Turbo deposits are from oxidation, nitration, polymerization, and any other of the detrimental chemical reactions and/or insufficient detergency/dispersancy. Volatility is a phase change from liquid to gas. High volatility could trigger deposits if a gas bubble forms and then the thin film remaining gets cooked but I don't know if that ever or generally happens. That is an indirect effect while chemistry has a direct effect. What I'm getting at is you could have a high viscosity, low volatility oil that cokes up like crazy and vice-versa. By the way, M1 5w30 does NOT have great (low) volatility.

 

[Max_Wander]

JAG, again thanks for a decent explanation differentiating volatility and coking.
Buster, tig1 I don't have an RDX but I do want all the information I can get regarding oils for turbo applications. Thanks to healthy discussion, I'm now fully aware that HTO focuses on an aspect I'm not concerned with at all

 

[Doug Hillary]

Hi,
JAG - You said this;
"................. then the thin film remaining gets cooked but I don't know if that ever or generally happens"

When turbo chargers were first put into "volume" production during the 1950s this was indeed the major cause of failure. This was not helped by poor turbocharger location, the nature of the lubricants of the time and insufficient oil cooling and flow. Some early engine families to suffer these problems were from Porsche (924), Mitsubishi, Volvo, Saab-Scania, Mack etc to name a very few. A quick and partial fix was to insist on a 3-5min idle down in order to slow the "cartridge" down from its up to 200000rpm spin around. Most "coking" occurred after shut down of course

This all led to engine specific lubricant specifications and much engine and component modification

Modern semi and fully synthetic lubricants (and more positive API/ACEA specification) have largely erradicated any carry over issues even with older engines

 

[d00df00d]

Max_Wander, keep in mind: turbocharger lifespan is not the only important factor for the RDX. There are a few other things as well:


- The turbo has to spool as quickly as possible. That requires a thin oil to reduce drag.

- Again to facilitate quick spooling, the turbo has to be close to the engine. That increases temperatures.

- Turbo temps are also increased by the high EGTs, which are necessary for emissions reasons.

- Oil helps cool the turbo, and thin oil cools more effectively.

- Honda engines in general wear very well no matter what oil you put in them.


That's why viscosity (including HTHS) can't be too high, wear control just has to be decent, and coking protection is supremely important.

 

[wgtoys]

"But all of us know that Amsoil could pass these tests with flying colours but chooses not to because of the expense to have them certified and would rather put this money into Marketing and their quality of product."

Knowledge requires factual information. You can only know something if you have hard evidence. Otherwise you think, feel, hope, surmise, assume or believe. Thus you may believe Amsoil could pass these tests if they wanted to, but you don't know it.

 

[MKZman]

Maybe the answer is to not buy vehicles that require oils not readily available in multiple brands if equivalent engines perform as well without special oils?

 

[OVERKILL]

Originally Posted By: MKZman
Maybe the answer is to not buy vehicles that require oils not readily available in multiple brands if equivalent engines perform as well without special oils?



Then what about those doing the opposite: Running boutique oils with only basic or completely lacking any official approvals in engines specifying specific API or ACEA ratings?

FWIW, M1 and PP are both very readily available.......

 

[Max_Wander]

Originally Posted By: OVERK1LL
Originally Posted By: MKZman
Maybe the answer is to not buy vehicles that require oils not readily available in multiple brands if equivalent engines perform as well without special oils?



Then what about those doing the opposite: Running boutique oils with only basic or completely lacking any official approvals in engines specifying specific API or ACEA ratings?

FWIW, M1 and PP are both very readily available.......


What's funny about engines, is that they don't give a poop about politics.

 

[d00df00d]

Originally Posted By: OVERK1LL
Then what about those doing the opposite: Running boutique oils with only basic or completely lacking any official approvals in engines specifying specific API or ACEA ratings?

Zing.