HTHS

dustyjoe1 · Nov 24, 2004

Until I read this post I was pretty set on running 5w20 in all my vehicles because of the increased mileage potential, however, I am now considering going to 5w30 on my honda civic which sees redline occasionally and 10w30 or straight 30 on my pickup for obvious reasons. Thank you all for the clear explanation of the importance of ht/hs.

regards

r.

crossbow · Nov 27, 2004

Remember that thicker oils don't necessarily have higher HTHS weights. One of castrols 10w-40's has a lower HTHS # then redline's 5w-20...

Primus · Nov 28, 2004

Recently discovered that Motul 300V 5W-40 has nearly 9 % higher HT/HS than 300V 10W-40 though theoretically it should be quite the reverse:

............................ 5W-40 .... 10W-40
Viscosity at 40 C ...... 80,8 ........ 89,5
Viscosity at 100 C .... 13,8 ........ 14.0
HT/HS .................... 4,51 ........ 4,19

Base stock is nearly similar. Can it really be that esters used in biodegradable version are more stable ?

MGBV8 · Nov 28, 2004

The 5W40 should not be mixed with other vis, so something unusual.

Steve S · Nov 29, 2004

Could the 05w/40 have more vi improvers than the 10w/40?

MolaKule · Nov 29, 2004

quote:

Base stock is nearly similar. Can it really be that esters used in biodegradable version are more stable ?

Yes, there are two possible reasons.

I have a technical paper that shows natural esters to be more stable at higher temps, have better resistance to shear, and better AW qualities at higher temps.

It could also be that base PAO's could include a higher viscosity PAO base stock in the mix.

MolaKule · Nov 30, 2004

As per above, not necessarily.

Theoretically, an oil with more VII should be less shear stable.

noob · Dec 1, 2004

quote:

Originally posted by friendly_jacek:

quote:

Originally posted by MolaKule:

So a "thin" 5W20 synthetic or mineral could have a real good HTHS.

Click to expand...

Interesting statement. Last time I checked, oils with "a real good HTHS", which I define >3.5, are quality XW40 oils, except for the thick-30 GC with HTHS of 3.6.

Don't foget about Motul 300v 5w30 who's HTHS is 3.61

JohnBrowning · Jan 7, 2005

This thread is so relavent to just about all of the oil converstions I wanted to bring it back to the top!!!

It should be required reading!!! It clearly illastrates what every one should be looking for in their oil. I am sure we can all find an oil with an HTHS 3.1 or higher in any weight of oil we need from 5W20 on up to 15W40!!

What we need now is an HTHS compendium of oils!

Drew99GT · Jan 8, 2005

This is one reason why I push the High Mileage oils. In general, per Pennzoils data sheets, they have a HT/HS that is about .2 higher than regular oils, within each viscosity grade. This is another reason why I don't like the new Conoco synthetic blend 5w-30s (sold also as motorcraft) HT/HS is only 2.9, where as it used to be 3.2.

buster · Jan 8, 2005

What is interesting is the drop off in wear as you go up in HT/HS, which suggests thicker is better.

Why though haven't we seen that on BITOG? Also, that test was done on one specific engine correct? If so, how is that test even objective?

Bobert · Jan 8, 2005

quote:

Originally posted by Primus:
Recently discovered that Motul 300V 5W-40 has nearly 9 % higher HT/HS than 300V 10W-40 though theoretically it should be quite the reverse:

............................ 5W-40 .... 10W-40
Viscosity at 40 C ...... 80,8 ........ 89,5
Viscosity at 100 C .... 13,8 ........ 14.0
HT/HS .................... 4,51 ........ 4,19

Base stock is nearly similar. Can it really be that esters used in biodegradable version are more stable ?

I noticed also that the Motul 300v Power 5w-40 had a high HTHS. The only other oils I've seen that are in the same league are the VW 505.01 Castrol 5w-40 oil @ 4.5 HT/HS, and the Redline 5w-40 @ 4.6 HT/HS.

The kicker is the Castrol is about $12.50 per quart, and Motul oil is about $12.95 per quart. They should be rename the Castrol 505.01 oil to "Liquid Gold" and the Motul 300v Power to "Liquid Platinum".

The Redline is a steal at about $7.00-$8.00 a quart.

I'd really like to try the Motul 300v Power 5w-40, but I'd have a hard time having my engine gulp around $75.00 worth of oil.

MGBV8 · Jan 9, 2005

The Motul 300V are race oils and may contain a different additive mix to a road oil, although can be used as a road oil. The Castrol I assume is for extended OCI and perhaps contains more additives. In the UK Redline is available as a road and race oil only. Is HTHS for road or race oil as I assume less esters in road oil.

Motorbike · Jan 9, 2005

quote:

Originally posted by Bobert:

VW 505.01 Castrol 5w-40 oil @ 4.5 HT/HS, and the Redline 5w-40 @ 4.6 HT/HS.

The kicker is the Castrol is about $12.50 per quart, and Motul oil is about $12.95 per quart. They should be rename the Castrol 505.01 oil to "Liquid Gold" and the Motul 300v Power to "Liquid Platinum".

The Redline is a steal at about $7.00-$8.00 a quart.

Click to expand...

Click to expand...

That Castrol can be had for less than 5 bucks a quart from a local distributor or online .
Part # ZVW352540S ...... a online link is in your PM box .

Dr. T · Jan 9, 2005

I also think there are occasionally errors in manuf. posted specs. (either typo or otherwise).

TallPaul · Jan 27, 2005

quote:

Originally posted by Jason Troxell:
... And what are the applicational differences between all the [HTHS] test methods: D4624,D4683,D4741? Obviously they are with a capillary viscometer,tapered bearing, and tapered plug respectively. But, do they have different results or different application interpretations?

I don't believe this was ever answered. Does anybody know if one method will produce a different result? Redline oil is measured by D4741, whereas most other oils are D4683. Just wonder if Redline would come in lower on D4683 and, if so, is there a conversion rule of thumb?

MolaKule · Jan 28, 2005

We'll do some research on it and try to give you an answer.

---------------------------------------

Quid quid latine dictum sit altum videtur.
(That which is said in Latin sounds profound.)

AEHaas · Jan 29, 2005

I was just looking at a 2003 ASTM testing list. D4624 and D4741 are no longer listed.

Only D4683 is listed now: Measuring Viscosity at High Shear Rate and High Temperature by Tapered Bearing Simulator.

aehaas

TallPaul · Jan 30, 2005

I just sent the following E-info request to the Redline:

quote:

Redline oil is measured by D4741, whereas most other oils are D4683. Additionally someone indicated the D4741 is no longer listed in the 2003 ASTM and so appears to be an obsolete test. My question is, how do I compare the HTHS of Redline with other oils when they used two different methods? Redline looks like it has a LOT more HTHS viscosity than other oils, but how can we know for sure. Do you have D4683 data, or a conversion factor?

buster · Jan 31, 2005

Thanks. I'm interested in hearing their response.

HTHS

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