Originally Posted by ka9mnx
The subject is heavier grade (weight) for older engines.
Mobil1 EP HM 10w-30
KV@100C 10.2
KV@40C 63.7
HTHS 3.1
Mobil1 HM 10w-30
KV@100C 12.1
KV@40C 78
HTHS 3.5
Mobil1 HM 10w-30 is clearly the heavier oil and probably less expensive.
Originally Posted by ka9mnx
BTW I don't see why the vanilla Mobil1 wouldn't fulfill your 10k OCI requirements.
You'd said EP was overkill for my application; I was wondering why. M1 guarantees the EP formula to protect for 15,000 miles, where they make no such guarantee for the standard formulation. There have been times (in fact, it's common) that I go a few hundred miles over 10,000 before I have a chance to do an oil change. I like the cushion that EP provides. Additionally, the EP variant contains more PAO, which I also like.
In the last couple of years, I've also become a fan of 10W-30 oils as compared to 5W-30, due to a lot of research I've done due to owning my WRX.
10W-30s tens to be more shear-stable, more resistant to dilution, and have better NOACK ratings than 5W-30s.
I've just used the M1-EP 5W-30 for so long, and the truck has run so well on it, that I've seen no reason to switch.
But now that there is an HM version of EP, it's got me thinking, since 206K in the truck...
IMHO, M1 oils are one of the best value oils on the market.