Is M1 TDT a true HDEO, equivalent to Delvac1 5W-40

[OVERKILL]

Originally Posted By: sdude2k2000
I think you missed my point... I wasn't focused on the warm temp values, but the cold temp ones.

T6 5w40 = 87
Delo 5w40 = 88.5
Redline 15w40 = 97
M1 5w40 = 97.9
Amsoil AME 15w40 = 98.4

The TDT does have a lower HTHS value (3.8) than all the listed oils, which may play into why it's able to maintain pumping ability at lower temps despite being thicker than the other 5w's I listed at cold temp.

Mobil seems to take the same approach with their Delvac 5w40 as well (higher viscosity, lower HTHS).

I was only making an observation.


As Garak noted, "Cold temp" is actually cold and is measured according to that chart I posted earlier

40C isn't "cold" (it is 104 Fahrenheit). It is just the lower of the two points the "hot" grade of the oil is measured at (the 40 in SAE 40, 5w-40, 10w-40...etc). Using the 40C and 100C values, that's how VI is calculated.

 

[Garak]

If our "cold" temperatures in this province were 40 C, I'd gladly run a monograde.

 

[SilverC6]

I wish Mobil would get their certs in order on M1 TDT or bring Delvac 1 5W-40 strongly to the US commercial market.

I would buy Delvac 1 5W-40 with its Cummins cert exclusively for my truck if it were available at Walmart.

 

[Hessam]

I tried running TDT in my LX450 for 2 cycles, but was losing too much oil (about 2qts per 1500 miles), compared to T6 which I normally lose about 1.25qts per 1500 miles.
Other than minor valve cover gasket leak, there are not known engine issues. Spark Plugs are dry and in great shape after almost 40K.

I too would like to try Delvac 1 5W-40, if it were readily available here in the US.

I have even contemplated running the M1 5W-30 HM in the LX450, but not sure if that engine would like the switch to a lighter weight oil (even though M1 5W-30 HM is a pretty stout 30 weight oil).

 

[Oil Changer]

Absolute gems from Garak and OVERKILL. Too bad this information will be lost in this sub-forum.

OVERKILL, you are the master of concise explanations.