From M1 HM 10W40 to AMSOIL ZROD 10W40 95 JAGUAR

Here's what I found:

0W-30, 5W-30 (Below 40)
The use of 0W-30 and 5W-30 oils is allowed during ambient temperatures of 50-104 F (10-40 C) ONLY if: the oil is purely synthetic, the oil meets API SH/CF and CCMC G5 specifications.
10W-30, 10W-40, 10W-50 (-20 To 40)
10W-60 (Above -20)
15W-40, 15W-50, 20W-40, 20W-50 (Above 0)
5W-20 (Below -10)
5W-40 (Below 40)
 
No need for that. Although it is a flat tappet its not the same as before with stiff springs and any decent hdeo would be fine. I'd run any rotella since its cheap and all reliably will have a great package. i believe that even Pennzoil said their platinum or ultra platinum was suitable for flat tappet engines which i kind of can believe.

You have to remember that oils as a whole back then were ass compared to what we have now and you basically needed a lot of zinc to not ruin the engine but modern oils can deliver.
 
Thank you for your reply.
I do wish I had gone to Amsoil Z Rod back when I got the car. I would not be having this problem now, I just was not aware that companies could continuously reformulate an oil but still call it the same thing at that time, and M1 HM was so easily accessible.

As I said, my ONLY concern making the switch now, is that the car has been running on M1 HM for 8 or 9 years, is leaks. …..The car has no leaks at the moment, but I can’t imagine that every seal in my engine is in perfect condition. But I have zero engine leaks, and I do attribute that, perhaps incorrectly, to the M1 HM…
The more you post the more you keep sounding like an Amsoil advertisement.

What "problem" are you having exactly? Why do you need an elevated ZDDP level again? As far as I can see there is zero technical reason the Mobil 1 HM isn't adequate for your vehicle. The only time really elevated levels are needed are during break-in of a new flat tappet engine and this isn't your situation.

Here is a page on the ExxonMobil site mentioning ZDDP levels with a link to a PDF file showing the specifics:

 
The more you post the more you keep sounding like an Amsoil advertisement.

What "problem" are you having exactly? Why do you need an elevated ZDDP level again? As far as I can see there is zero technical reason the Mobil 1 HM isn't adequate for your vehicle. The only time really elevated levels are needed are during break-in of a new flat tappet engine and this isn't your situation.

Here is a page on the ExxonMobil site mentioning ZDDP levels with a link to a PDF file showing the specifics:

Good morning to you as well.

The link you posted to M1 10W40 HM is outdated. Back then the ZDDP was 1100. After the latest reformulation it is 900. It was 1000 for a while between those two

The reason I want to switch away from M1 HM is because of the dropping ZDDP. My engine is flat tappet and my understanding is that the ZDDP should be no less than 1000. I would actually prefer to keep using the same product, but since they continue to reformulate and drop the ZDDP, that no longer seems feasible. Amsoil Z rod is the only one I have researched and seemed like a good fit for my engine.

I outlined this in the first post, which perhaps you could have read instead of berating me for looking at a product you may or may not personally dislike.
 
Good morning to you as well.

The link you posted to M1 10W40 HM is outdated. Back then the ZDDP was 1100. After the latest reformulation it is 900. It was 1000 for a while between those two

The reason I want to switch away from M1 HM is because of the dropping ZDDP. My engine is flat tappet and my understanding is that the ZDDP should be no less than 1000. I would actually prefer to keep using the same product, but since they continue to reformulate and drop the ZDDP, that no longer seems feasible. Amsoil Z rod is the only one I have researched and seemed like a good fit for my engine.

I outlined this in the first post, which perhaps you could have read instead of berating me for looking at a product you may or may not personally dislike.
I have no issues with Amsoil products whatsoever and I'm not sure why you would think that. I made the observation based on your posts. In fact I currently use Amsoil gear oil in my ECHO.

Yes the sheet may be outdated I agree. But again what technical reason do you have for understanding that your engine needs that level of ZDDP?
 
Here's what I found:

0W-30, 5W-30 (Below 40)
The use of 0W-30 and 5W-30 oils is allowed during ambient temperatures of 50-104 F (10-40 C) ONLY if: the oil is purely synthetic, the oil meets API SH/CF and CCMC G5 specifications.
10W-30, 10W-40, 10W-50 (-20 To 40)
10W-60 (Above -20)
15W-40, 15W-50, 20W-40, 20W-50 (Above 0)
5W-20 (Below -10)
5W-40 (Below 40)
Good info but if those recommendations came out of the 1995 Jag manual, they are severely outdated. My 1993 F150 requires API SJ and I'm having a terrible time finding it.
 
@MNJ85 Call or email AMSOIL (I would call them) and voice your concerns with them. Let us know what they say.

I don't have the time or inclination to talk about High Mileage oil, however, in a nutshell:
The primary function of high mileage motor oil, contrary to popular belief, is not to condition seals. It contains a smidge more seal conditioner, but it's not outside of API limits. Its primary function is to provide older formulations for older engines, not just mileage-wise but also time-wise. Usually, in the same grade, High Mileage oil is slightly thicker and contains a more "traditional" additive package that's a little bit more beefed up. For example, if you drive a Hyundai Sonata with a 3.3L V6 from 2008 that has only 55,000 miles on it, you might want to run Mobil 1 High Mileage in it. You don't have to, but it's a good idea because those engines are older technology. This would work even better if I used the 2.7L V6 in that era's Santa Fe as an example.
 
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I have no issues with Amsoil products whatsoever and I'm not sure why you would think that. I made the observation based on your posts. In fact I currently use Amsoil gear oil in my ECHO.

Yes the sheet may be outdated I agree. But again what technical reason do you have for understanding that your engine needs that level of ZDDP?
Thank you for your reply.

The fact that the AJ16 straight six Jaguar engine is a flat tappet engine would be my “technical” reason. I understand that flat tappet engines need a ZDDP level of 1000 or more.

Quite honestly, M1 HM has served me well, and it was ideal in the sense that it had the high mileage package I preferred and the high zddp content at 1100 and later 1000. But this is no longer the case, hence my search for a replacement.
Thanks
 
@MNJ85 Call or email AMSOIL (I would call them) and voice your concerns with them. Let us know what they say.

I don't have the time or inclination to talk about High Mileage oil, however, in a nutshell:
The primary function of high mileage motor oil, contrary to popular belief, is not to condition seals. It contains a smidge more seal conditioner, but it's not outside of API limits. Its primary function is to provide older formulations for older engines, not just mileage-wise but also time-wise. Usually, in the same grade, High Mileage oil is slightly thicker and contains a more "traditional" additive package that's a little bit more beefed up. For example, if you drive a Hyundai Sonata with a 3.3L V6 from 2008 that has only 55,000 miles on it, you might want to run Mobil 1 High Mileage in it. You don't have to, but it's a good idea because those engines are older technology. This would work even better if I used the 2.7L V6 in that era's Santa Fe as an example.
Thanks for your reply. I did call, and while they extremely helpful and knowledgeable, when it came to the point of the “seal conditioners” in their product they told me “that is something they don’t advertise”

So that is why I am relying on the anecdotal experience of members here and those who know more than me to try to discover (probably impossible) how my engine will react going to the Amsoil Z Rod. This is the only thing holding me back from placing an order with them. Since as you say, the conditioners in the M1 HM are just elevated quantities of what they normally use, the more logical question is if users of Mobil 1 to Amsoil in higher mileage vehicles typically experience leaks, or rather, does the Amsoil make existing leaks more evident.
 
Yes I posted that above. The OP indicated that the listing is inaccurate.
The OP needs to read the oil specifications and understand them. Mobil 1 HM 10W-40 is an API SP motor oil that is not backward compatible with anything beyond API SN. That means, amongst other things, a limit of 800ppm on Phosphorus since the API no longer grants an exemption for xW-40 motor oils or higher.

10W-40 is not on the list that I provided, so I don't know to which inaccuracy you or he refer to.

@MNJ85 unless you're trying to pinch pennies, you need to get the correct oil for a classic car from AMSOIL, Driven, or any other manufacturer that formulates a motor oil for your vintage automobile. Royal Purple HPS and HPR are also high ZDDP options and pretty decent, I might add. If you're looking to save a buck, then take a look at the list I provided because it's pretty on point and accurate.

So, to recap, you need an oil with the proper formulation for your vintage vehicle. Looking at ZDDP numbers alone is not enough, as ZDDP has changed and evolved, and how it works, and so has the Phosphorus/Zinc ratio. There is a technical discussion from Castrol Australia from over a decade ago on this forum that, even back then, they changed how ZDDP functions within oil formulations and makes their own recommendations on what to use for flat tappet engines. So, if it's about saving money, then you need to make that clear. You might as well Mobil 1 Racing Oil and call it a day, as it has lots of everything, except detergents.
 
The OP needs to read the oil specifications and understand them. Mobil 1 HM 10W-40 is an API SP motor oil that is not backward compatible with anything beyond API SN. That means, amongst other things, a limit of 800ppm on Phosphorus since the API no longer grants an exemption for xW-40 motor oils or higher.

10W-40 is not on the list that I provided, so I don't know to which inaccuracy you or he refer to.

@MNJ85 unless you're trying to pinch pennies, you need to get the correct oil for a classic car from AMSOIL, Driven, or any other manufacturer that formulates a motor oil for your vintage automobile. Royal Purple HPS and HPR are also high ZDDP options and pretty decent, I might add. If you're looking to save a buck, then take a look at the list I provided because it's pretty on point and accurate.

So, to recap, you need an oil with the proper formulation for your vintage vehicle. Looking at ZDDP numbers alone is not enough, as ZDDP has changed and evolved, and how it works, and so has the Phosphorus/Zinc ratio. There is a technical discussion from Castrol Australia from over a decade ago on this forum that, even back then, they changed how ZDDP functions within oil formulations and makes their own recommendations on what to use for flat tappet engines. So, if it's about saving money, then you need to make that clear. You might as well Mobil 1 Racing Oil and call it a day, as it has lots of everything, except detergents.
Without being presumptuous, it’s not about money at all. To condense it to one sentence: it’s about the fear/cowardice that the seals in my car, after 8 years on Mobil 1 HM, are going to start weeping with the Amsoil. That’s it. Nothing more nothing less.
 
Without being presumptuous, it’s not about money at all. To condense it to one sentence: it’s about the fear/cowardice that the seals in my car, after 8 years on Mobil 1 HM, are going to start weeping with the Amsoil. That’s it. Nothing more nothing less.
They won't. If you want to hear it from someone who knows for sure, try and reach out to @MolaKule, he is an oil formulator, and he set me straight more than once when I was wrong. Please consider that he is also constantly swamped with work, and who knows how many others constantly reach out to him with questions, so it may take some time to get a reply.

Or read this thread: https://bobistheoilguy.com/forums/threads/high-mileage-oil-just-contains-seal-swellers.331495/

You should also reach out to AMSOIL and Driven and see what they advise you to do. Mass-produced motor oils are constantly modernized, and the manufacturer lists their backward compatibility. That's what you can trust, not anecdotes about the ZDDP level. For example, Delo 600 contains ZERO ZDDP, as it is a modern HDEO oil formulation meant to protect the DPF in modern trucks. And modern diesel engines in trucks don't need a lot of ZDDP, to begin with. It's a popular misconception that running a Diesel HDEO in a gasoline vehicle that's either moded (Subaru crown loves Rotella T6) or old is a good thing. It's far from the truth, and you can grenade your engine by doing so. So, I think that it's only reasonable to get in contact with the manufacturers I mentioned. Their spec sheets also list compatibility so that you can go by that.
 
They won't. If you want to hear it from someone who knows for sure, try and reach out to @MolaKule, he is an oil formulator, and he set me straight more than once when I was wrong. Please consider that he is also constantly swamped with work, and who knows how many others constantly reach out to him with questions, so it may take some time to get a reply.

Or read this thread: https://bobistheoilguy.com/forums/threads/high-mileage-oil-just-contains-seal-swellers.331495/

You should also reach out to AMSOIL and Driven and see what they advise you to do. Mass-produced motor oils are constantly modernized, and the manufacturer lists their backward compatibility. That's what you can trust, not anecdotes about the ZDDP level. For example, Delo 600 contains ZERO ZDDP, as it is a modern HDEO oil formulation meant to protect the DPF in modern trucks. And modern diesel engines in trucks don't need a lot of ZDDP, to begin with. It's a popular misconception that running a Diesel HDEO in a gasoline vehicle that's either moded (Subaru crown loves Rotella T6) or old is a good thing. It's far from the truth, and you can grenade your engine by doing so. So, I think that it's only reasonable to get in contact with the manufacturers I mentioned. Their spec sheets also list compatibility so that you can go by that.
Thanks for your response.
I called (again) today, and explicitly asked about seal conditioners in their products. They said “all their products have seal conditioners, and the z-rod is no exception. I don’t think I can get any more information other than that. It’s just a matter of me taking the risk that their seal conditioner additives are similar to what M1 High Mileage has.

Thanks
 
Thanks for your response.
I called (again) today, and explicitly asked about seal conditioners in their products. They said “all their products have seal conditioners, and the z-rod is no exception. I don’t think I can get any more information other than that. It’s just a matter of me taking the risk that their seal conditioner additives are similar to what M1 High Mileage has.

Thanks

Who knows, they might be the same? Amsoil gets their base and additives from other companies. They just blend.
 

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