High performance lubricants

In short, base oil is base oil and essentially where the viscosity rating comes from. The additive pack is what makes an oil good, poor, or amazing. And it’s not just quantity of specific additives but combination as well that fortifies the oil against wear, friction (different than wear), condensation, etc.

It’s a rabbit hole to fall down for sure, but suffice to say that Toyota specs a specific additive package for their 0w20 that isn’t the same as off-the-shelf Mobil 1 even though Mobil produces it for them.

What’s “best” is relative.

 

I use to work for them in the QC lab and there stuff is legit. They have a more stringent set of standards of how the viscosities should perform. You would be fine to run 15k and I bet that oil would still be a 5W30 if you sent it in for viscosity, HTHS, and TBN testing.

 

I wouldn't be too concerned. I don't know if it was just a fluke or poor fit for my vehicle. I didn't send diff oil in to Blackstone, just the motor oil. David mentioned that some of the additives can show up on the report as metals; I don't know why or how, but they are all just chemicals. I mean, baking powder usually contains aluminum... Per my Blackstone report, my aluminum was double the norm, and copper appeared for the first time. I switched to another oil and aluminum dropped back down to normal and has continued in that range for four or five more changes. Additive pack was still strong. All three of us - myself, David, and Blackstone were a little baffled.

I had an Auburn LSD in the rear diff with a few miles on it (replaced with a SpeedMaster helical gear type LSD). It was admittedly fairly worn, but still functional as long as I maintained the friction modifier additive in the oil. Every 15-20k it needed to be changed (I haul and tow a lot). I gave HPL DiffLite a shot after chatting with David. He recommends 75w90 for virtually every light duty truck, including his own Dodge Diesel, and let me know that I shouldn't need to add any Friction Modifier as it's already included in the fluid.

Shortly after changing the fluid, I needed to help drag a buddy and his trailer out of the snow up in the mountains in a snowstorm. The ride up was pretty clunky, and the rear behaved like a locker while recovering the trailer, but once I got back on the highway to head home, the rear was chunking and clunking and locking up all over the place. I had to put it in 4wd most of the way home just to keep the rear end from kicking out. I added one bottle, then two bottles (the norm for the Auburn), then 3 bottles just to get it to stop chattering and clunking. After a couple of months, the chattering came back so I changed the diff oil and found a couple of large pieces of metal stuck to the magnetic drain pan. I nursed the Auburn along for another year but it required FM every 5k miles or less from then on until I replaced it.

My front diff ran it for another year until it needed a few long workouts traveling home in snowstorms. One particularly bad winter storm required 4WD for several hours pulling a trailer home. Speeds were under 45 MPH but the trailer was plowing snow a few times. Half way home the front diff started buzzing/grinding around 45 MPH and just got worse. I had to finish the trip in 2wd, which was pretty hairy. I changed fluid and it appeared to go away for a while but is still there, albeit quieter. My buddy will be pulling the diff as soon as I get my blower back from Whipple and can drive the truck again.

I used it in my sequoia as well, but now have a bearing issue. I can't say with 100% certainty that it was an issue with HPL oil, but all of the vehicles that I've used it have had issues within a year of use. I've had zero issues with the tundra in the decade prior to using HPL; same usage.

 

Thank you so much for your reply! I understand a bit better now.