Another What Oil do u use thread

[XfireZ51]

Been looking for oil to replace the CASTROL GTX I had been using for a number of years. It is a conventional so wanting a synthetic.
Well, I found MOBIL 1 15W-50. Here are the specs which look like it contains adequate levels of ZDDP. Has anyone else discovered and been using it?

[secondchance]

In 2014, after an engine rebuild, my oil pressure was unusually and uncomfortably low - 15 psi or so. I used Mobil 1 15W-50 just to increase the low rpm pressure 'cause it was the only thing I could do. It turned out to be a crankshaft oil galley plug that popped out.
After years of using Mobil1 and Mobil 1 High Mileage, I gave up a couple of months ago and went to Amsoil Z-Rod 10W-30 over the same concern - ZDDP.

[Gunny]

Amsoil may be your solution. At one time I used M1 high mileage 10W40 that had the higher ZDDP but Mobil "quietly" changed the amount of ZDDP to a lower level. Click HERE for the current M1 oil specs. I have spec sheets from 2011 & 2014 showing that M1 high mileage 10W30 & 10W40 with a phosphorus level of 1000 and zinc level of 1100. Those levels were reduced some time after 2014 but, without access to later spec sheets, I'm not certain when that happened.

[XfireZ51]

Gunny,

Here’s the link to Mobil product specs on oils. You’ll note that the 15W-50 specifically mentions flat tappets and that the zinc content is within the acceptable range for our motors unlike Mobil 1 High Mileage 10W-40 which I have been using more recently.
The 15W-50 can be had at Walmart, as an example, for $22/5qts. I am changing to this for other reasons in addition to the ZDDP insufficiency.
You’ll note that this .pdf was published just this month, June 2019.

https://mobiloil.com/~/media/amer/us...pecs-guide.pdf
Same link.

[spork2367]

There is a thread with literally ALL this information already in it...

http://www.zr1.net/forum/showthread.php?t=30261

15W-50 is considered by most to be a little on the heavy side for a stock LT-5, but I wouldn't be super worried unless you were running it in low temps.

[Flyman 27]

Dom, I also did the same research you did and came to the Mobile 1 15w50 as a possible solution. And, Walmart does carry it regularly, but they also sell it online with free shipping. 5 qts for $23 is pretty darn cheap, but that was not part of the equation when I decided to change.
I have been using the Mobile 1 15w50 for 3 years now without issue. But I do not drive in cold weather at all.

[XfireZ51]

Originally Posted by spork2367

There is a thread with literally ALL this information already in it...

http://www.zr1.net/forum/showthread.php?t=30261

15W-50 is considered by most to be a little on the heavy side for a stock LT-5, but I wouldn't be super worried unless you were running it in low temps.

Always an interesting topic. I would agree w Hans in that thread, that the seat and spring pressures our motors experience(a benefit of 4v OHC architecture) don’t reach what the LS/LT motors need to run for the in-block cam setup to breathe as well. So the need for ZDDP not as great and I think we have examples of being able to “get away with” lower ZDDP content.

[XfireZ51]

Originally Posted by Flyman 27

Dom, I also did the same research you did and came to the Mobile 1 15w50 as a possible solution. And, Walmart does carry it regularly, but they also sell it online with free shipping. 5 qts for $23 is pretty darn cheap, but that was not part of the equation when I decided to change.
I have been using the Mobile 1 15w50 for 3 years now without issue. But I do not drive in cold weather at all.

I drive in cold weather only on occasion of clear skies and dry roads and then really to just get fluids up to temp and get some of the dust off the brakes and greases moving. For the most part, ZR sits there w neg cable disconnected.I try to start it every few weeks but wait for outside temps to be over freezing.
Good to know Dan.

[secondchance]

Originally Posted by XfireZ51

Always an interesting topic. I would agree w Hans in that thread, that the seat and spring pressures our motors experience(a benefit of 4v OHC architecture) don’t reach what the LS/LT motors need to run for the in-block cam setup to breathe as well. So the need for ZDDP not as great and I think we have examples of being able to “get away with” lower ZDDP content.

I had this discussion with multiple people including Marc and fully agree spring pressure on on our motor is not as high as OHV engine. However, pressure increases with RPM. Now, our LT5 will see 7,000 RPM at times (hopefully) where as typical OHV V8 seeing 6,000+.
In the end, i decided it simply was not worth the risk and started buying Amsoil online.

[lfalzarano]

I decided not to cheap out on my Z and also use Amsoil. Stick with Marc and not your Piggy Bank!


Sent from my iPhone using ZR-1 Net Registry