AMSOIL low HTHS? and HTHS questions.

[buster]

Quote:

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The thing I find a bit ironic is the fact that Amsoil used to build several of the listed oils (the PAO oils ASL, ATM) on the thick, higher HTHS side

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It is ironic. It used to be one of Tooslick's selling points. LOL

Amsoil used to make oils the old fashion way, with a lot of ZDDP for wear protection and extended drains. It was also good for being a true racing oil for older, high horsepower engines. IMO.

I think with GF-4, it put them in a position where they had to start updating the technology being used in their oils. The new stuff is working great, and I'm sure they are using high quality additives. Most other API Synthetics have been using moly for quite some time to pass the GF-4 test.

 

[cfromc]

Sorry, long post:

Hey goodvibes, I used to live in Palatine. Love Mia Cucina and House of Hunan and that Mexican place near Dirty Nellies.

Anyway, I'll be changing oil in all my vehicles this month and for the two cars I think I'm going with:

4+ qts Redline 5W-20 + 2 qts 5w30 in the Suburban (will be a little over 4qts 5W-20 due to larger filter) which will give ~3.4 HTHS, ~9.6@100C, ~58@40C, ~5200@-30C. The specs fall into a thin 5w30 range and Redline is known for holding its viscosity. I plan on using no oil additives at all, using an Amsoil EaO30 filter, and running 10K OCI's, which will be about every 8 months. It is not driven hard and is not used for towing/trailering. Its biggest workout is carrying 7-8 people with their "gear". I chose Redline because I wanted something a little thicker at start-up and up to 40C because it seems to like the thicker oils when cold (I know it doesn't sound right) but it is smoother and quieter. I also wanted something that was thinner at operating temperature to see if I could gain a little MPG. The Redline fits for what I am looking for and I will be doing a UOA for at least the next two changes to see if further "fine-tuning" is needed. I will first be doing a top engine clean and then about 1000-2000 miles with a cheap oil to flush anything out, then going to the Redline. I'm also hoping the Redline will clean out the system because I keep hearing that it does clean up a lot.

On the other car, Grand Prix GTP, I want something thinner than I'm using, especially at -30C and 40C, because the car sees a lot of short trips, but I still wanted something moderately thick at 100C and good HTHS because it is supercharged w/approx. 12psi boost. I chose Amsoil XL-series, 2qts 5W-20 and the rest 5w30 (approx. 2.7qts) with 2oz. VSOT for added moly. This mix should result in HTHS 3, 53@40C, ~10.5@100C and ~4118@-30 (I don't know what affect VSOT has on the -30C and 40C viscosities but I assume they will go up). This mix will give me a difference of about 1000@-30, 5@40, with just slightly lower HTHS and 100C visc. than the ASL I'm using now. The car does see a mix of driving but sees mostly short-trips several times a week. I want an oil that starts out thin but can still take frequent WOT running and remain within a 5w30 range. The OCI will be based on the OLM system which has been about 8,000 miles/9months in the past. I'll be running a PureOne filter that is the next size longer and I'll be changing the filter each OCI. The car runs cooler than stock and the coolant only gets to "operating" temp >190-195 if I'm stuck in traffic.

Am I on the right track or totally derailed?

 

[buster]

If I were to use RL again, I would always drop down a grade. For instance, if my car called for a 5w30, I'd use their 5w-20.

 

[cfromc]

They seem to be at the top of the range most of the time. The 5W-20 reads like a 5w30 except the 9.1cst@100, which is only .2 off from a 5w30.

 

[TooSlick]

I DO NOT recommend blending different viscosity grades as the basestock blends and additive packages can be different - even if made by the same manufacturer. It is almost impossible to analytically predict the viscometrics of these blends, you actually have to test them. I certainly don't recommending dumping in a can of snake oil off the shelf and expect that to improve the performance of any fully formulated engine oil.

If you're hard over on using Moly, I think that Redline is an excellent product. But I'd save the "Mixmaster" stuff for your next Rave...

If I owned these two vehicles I'd run their Series 3000, 5w30 in both, with a 10k-12k OCI. I'd do an oil analysis EVERY TIME I changed the oil in the GP, since I simply dont trust those GM gaskets. How that design ever got through their endurance testing I never know??? I'm guessing their bean counters ran the numbers and the repairs turned out to be less expensive that re-designing these engines. I think that John Browning would probably agree....

To answer your original question...Amsoil has reduced the HT/HS viscosities of their 5w30/10w-30 by approx 10% from the SL formulations. I suspect they did this to meet the fuel saving requirements of ILSAC/GF-4 and to improve their "stay in grade" performance over 15k-25k OCI's. The preliminary analyses I've seen on these two oils (and their S2000) are better than the previous formulation. This is particularly true in terms of thickening over long drain intervals, due to oxidation/evaporation.

Amsoil changes their add packs about every two years, so I wouldn't read too much into that. Their diesel oils, Four Stroke oils and motorcycle oils still use high levels of ZnDTP and those formulations work very well.

TS

 

[cfromc]

Thank you TooSlick for responding. I value your opinion. The reason I didn't want to go with the HDD is because it is a little on the thick side and it seems like it might be a little overkill. The number one priority for the Suburban is wear reduction but I also want a little better MPG and I doubt I will get that with the HDD. I thought I would have great protection and maybe a little better MPG with the Redline since it is thinner at 40C and 100C. While any MPG increase will likely be very small miles but the GP, I'm not sure about. Likely at least 2.5 more years but beyond that, I don't know. Because of the unsurety, I'd still like to reduce the wear as much as possible in case I keep it for a long time. Because of the short-trips and very cold weather coming up, I'd like to use something as thin as possible while still having protection.

As far as moly, I didn't think VSOT was snake oil. I thought it was one of the few additives that actually was worth something...I have noticed that the XL 5W-20 and 5w30 have some moly in them so I was only going to add 2oz.

Just when I thought I had a perfect plan, I have to re-assess the situation. Wish I had a heated garage, then I might just go with the HDD. Maybe I'll go with 100% XL-7500 5w30 in the GP since it is significantly thinner at -30C than the ASL I'm using now yet the 40C, 100C and HTHS are virtually the same. I still want to use the OLM 8-9000 mile OCI since it is under warranty and I may purchase extended coverage.

Anyway, thanks, this gives me something more to think about. I won't tell my wife it was your fault. She keeps saying I'm cheating on her with "Bob".

 

[cfromc]

Called Amsoil Tech line (also sent an email-will post their written response when I get it) Erin at Amsoil did not recommend the mixing of the two XL-series oils due to the differant additives used in each to achieve their respective weights and attributes. He did recommend the TSO 0w30 when I told him I wanted a "thin" 5w30 although he stated that the TSO is nearly the same at -30 as the XL 5w30. I really thought that mixing would be OK since I've seen some people on BITOG do it and have good UOAs. Based on my OCI I think the XL-7500 5w30 might be best for the GP.

 

[cfromc]

Called Redline tech line and spoke with Dave. Posed same question regarding their oils. Dave said it was perfectly fine with to mix Redline's 5W-20 and 5w30. Also sent an email with the same question-will post when I get it. Perhaps Amsoil's blends are more specific to the intended rating while Redline's are not...? Actually, this will be easier because I can just buy a case of XL-7500 5w30 for the car instead of having two cases. The Redline dealer by me sells individual bottles at a good price so I don't need to buy a case at a time. May still consider going with 100% Redline 5W-20 in the 'burb'.

 

[427Z06]

Quote:

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From my research, mostly on this site, but I've also been looking around the 'net, it appears that an HTHS of less than 2.6 is detrimental to wear, while wear is reduced as the HTHS goes to 2.9 to an "acceptable" level and wear is further reduced (a little) as HTHS goes higher.

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HTHS numbers apply to particular engine designs run under particular conditions. Even the 2.6 HTHS limit for some engines is based on a certain set of conditions, usually at WOT and full load. Many here are incorrectly extropolating the predicted wear reduction based on HTHS numbers generated in any particular study because they don't know the other parameters involved.

In short, the use of HTHS numbers to predict wear reduction of the average engine here is way overblown.

 

[cfromc]

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Many here are incorrectly extropolating the predicted wear reduction based on HTHS numbers generated in any particular study because they don't know the other parameters involved.

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Hey, I resemble that remark. Seriously, I'm just trying to find the oil with the specs that are the most ideal for my intended usage. There are so many choices out there that I might as well aim for the best.

 

[427Z06]

Just how much time can you spend at WOT on the street? I bet you if it was 10% you'd be driving like a maniac. Even if you were towing 100% of the time in the mountains the best you could do is 50% (you have to come down the other side).

 

[cfromc]

In the Suburban its probably .001%. The GP, well, more than .001%. It does get to beyond legal speeds pretty quick with 300hp, increased rpm-limits, and a reduction of the transmission's torque-management. Still not 10% of the time though.

 

[cfromc]

Response from Redline:

Message : Can your motor oil 5W-20 be mixed with your 5w30 to achieve a desired viscosity? Will there be any additive clash or other undesirable effects?


Thank you for contacting Red Line Oil, yes the various viscosities can be mixed to achieve one in between, there are no adverse reactions.

Regards, Dave
Red Line Oil

No written response from Amsoil yet.

 

[TooSlick]

My analogy on mixing various SAE grades:

You mix basketballs and ping balls and you get a physical mixture of basketballs and ping balls. What you don't get is the two spheres melding into something the side of a softball,which is what you want in this case.

In other words, you get a physical mixture of different sized oil molecules. This mixture of large/small molecules does NOT behave the same way "viscometrically" that a group of all medium sized molecules would. At low temps, the large molecules still thicken too much and at high temps the small molecules still break down rapidly.

Does that make sense?

TS

 

[cfromc]

Yes, it does. Maybe I'll try the 5W-20 since we're going into winter.

 

[cfromc]

Reponse from Amsoil:

Thank you for contacting AMSOIL with your concerns,

In response to your inquiry, AMSOIL does not recommend mixing viscosities of oils due to the chemistries

Thank you again for the opportunity to respond to your concerns. As always, please feel free to contact us again if we can be of further assistance.


Sincerely,
Dale Anderson
AMSOIL Technical Services