Truck in front of the camper

wnjj wrote:

mkirsch wrote:
8.1L's produce a lot of heat and do use oil, up to a quart every 1000 miles. Mobil 1 5W30 seems to hold up the best.

When I bought my 8.1L, my dad already had his. At the time he had read that running 10W30 helped reduce oil consumption. I cannot confirm it helps but I have been running it since new and at 70k miles it still goes a few thousand miles before it needs a quart.

I think I’d be pouring 15-40 Dino oil in it as needed. Just like virtually every other 4s engine I own or have owned, for years.
Afaik, the 8.1 is a “loose” motor, just as most big bores are/need to be. So not only do they like/can handle a bit higher viscosity, 15-40 is just universally fine unless a particular engine needs thinner oil for “real” reasons….like the tight, small bore, small oil return galley old Triton 4.2, 4.6, 5.4s. I’m sure there are others too.

One thing to consider is not just oil consumption, but randomly variable oil consumption. A characteristic that I’ve really only seen in big blocks, save for the 350 in my buddy’s boat.
Recent example is the motor in our 86 GMC. It’s a low mile (like 20-30k miles, tops) Mark VI GM crate motor straight from the dealer about 20 years ago. So not a powerhouse by any means but a step up from the TBI peanut port heads engines.

That thing will suck down a quart in 3 tanks of gas one time and not use a drop the next. And it’s only a cruiser, rarely/never works hard.
Just a couple days ago I was scolding the boy about last time he checked the oil. He admitted it probably needed oil. While he was working on something else I popped the dipstick so I could give him a good told ya so, and it was full right to the top dot!
Doesn’t leak a drop, not even oily around the mains or anywhere else. Doesn’t burn enough to even make a hint of blue smoke on cold starts. Just sometimes uses oil, sometimes it don’t!

I personally wouldn’t want that, knowingly, for a daily driver or even more so a tow pig. I’m more of a change the oil, shut the hood and forget about it until the next oil change….
Maybe an intermediate check if it’s well into an OCI and going to hit the road for some high miles or big towing.

Again, the OP being super budget conscious, the best rig is the best condition, low miles, for the best price he can find. Whether it’s wearing a bow tie or a blue oval or a goat w/horns on the grille.